Outdoor Photogrammetry Surface Scanning for Materials with a Flash
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- čas přidán 7. 06. 2024
- #photogrammetry #scanning #flash #tutorial #materials #photography
In this video I present a ring flash based photogrammetry setup for outdoor materials scanning. The idea for this one came after someone asked what the hell is this thing, after seeing the ring flash setup.
I start with some theory, move into details and finish with 2 tricky examples.
Hope someone finds it useful.
If you like it and want to see even more content like this one, please subscribe to my channel, share it and leave the thumbs up.
Big thanks who did it already as it really helps me to move forward.
Stay safe and till the next one
Cheers!
Grzegorz Baran
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Following your advice I split the video into sections so its easier to navigate on youtube
These are all key subjects covered:
00:00 Intro
2:44 Shadow Theory
7:10 ISO Explained
7:75 Outdoor Conditions
9:29 Flash Setup Details
13:58 Flash Power
14:43 Histogram Explained
16:10 General camera setting
16:44 Inverse Square Rule
17:24 Flash Angle
19:49 AR400 technical limits
22:40 Detailed Setting
24:34 Substance Response to cross polarisation
32:05 Complex Surfaces - Rocks
37:10 Overwriting the sun - Earth
40:36 Monopod approach
42:27 Outro
So much effort goes into these photogrammetry gems! Thank you, Grzegorz, for sharing it with us!
Thanks Gleb, very appreciated :)
You must be loved by 3d artists around the globe.
:)
Twoj kanał jest najlepszy jeśli chodzi o fotogrametrie, ogromna ilość cennych informacji. Dzięki.
Dziekuje bardzo! Naprawde milo mi to slyszec
Your channel is a goldmine. I'm so happy I came around this. I've always wanted to try to make my own PBR materials but there are not many quality in-depth tutorials out there like yours. Really good job.
Thanks, I am really glad to hear that. Still have a few interesting ideas for videos so stay tuned .. and good luck with your PBR materials :)
Amazing video, thank you kindly.
Thanks Chris :)
Thank you! Your videos are always very interesting.
Thank you very much. Cheers!
Dude, this is so in-depth, thank you so much!
Cheers :)
I used to collect it all from your older videos. i had no idea there was material with such a meticulous, exhaustive breakdown of high quality photogrammetry!
:D
These videos are a goldmine of information. Thank you so much for making them!
Great to know you found them informative Jon :) Cheers!
Great video again! So full of useful information. Thank you!
Thanks :)
Nice content, very well explained, Great Job! Thanks!
Thank you, appreciated
amazingly detailed information.
Thank you Terence :), doing my best
this is so detailed and so much content!!! thanks for sharing !
Cheers! Anytime :)
nice, great spots !!
Cheers! :)
just what i am looking for and also just in time!
Glad to hear that :), hope you are gonna find something useful in this one :D
i am more than thankful for this video in terms of usefulness :D
thx, very useful!
Thanks!
Wielkie dzięki za to co robisz :) Ilość wiedzy jaką przekazujesz jest powalająca!
Cala przyjemnosc po mojej stronie :)
Because of your videos ive become obsessed with photogrammetry. I've been learning 3d modeling and attempting indie game dev. My focus was achieving highly detailed but needed a way to generate my own textures as endlessly scrolling online libraries can time consuming and costly. Ive watched a lot of your videos multiple times and even bought your ebook. Maybe one day ill be half as good as you.
Hey, I am sure you can be even better to me, just never give up. Photogrammetry is just a tood though, one of many, and should be considered as one. It worth to know them all and pick the best one for the job. Good luck on your path
@Grzegorz Baran I appreciate it! I've managed to make a couple of successful 2x2m surface scans using your methods, which got me pretty excited. Is the process any different if I wanted a smaller texture such as a wooden fence, for instance?
@@Chaser2666 Nah, its just the matter of scale and coverage density, all principles are basically the same.
As Photogrammetry amateur (but Pro 3D), this is extremly good and clean, thanks !
Thanks :)
Thank you again very much for such great workflow analysis. I’ve been thinking to setup my self with monopod, but after seen your way of using tripod, I cant Imagine it would serve me with my photogrammetry workflow. Also the comparison with different substances and their way to react in ambient, unpolarized and polarized light was great! Absolutely great contnent!
Thanks. Yeah, the monopod is a better pick if you shot just with a camera in decent lighting conditions, but fails when used with heavier equipment and also when shooting complex surfaces like grass etc. in poor lighting conditions. I also use a monopod to record my videos :). These are reasons why I usualy carry both but if I have a choice I would pick a tripod as a tripod can also work as a monopod if you stick legs together [42:02] while monopod can't stabilise the camera as good as a tripod can.
Wonderful share, thank you!! Leaving my support, friend!
Your video is great!
Have a Lovely Day 💜 Greetings!
Thank you, very appreciated
Man, love your videos! Just finished printing my turntable for indoor Photogrammetry. I hope I can come by with my not so great ring light for now. At least got a polarizing filter and foil to mount on the ring light. Super stoked to see the first results...
Cheers! Good luck with your setup dude :)
I study 3D CGI so stuff like PBR, Photogrammetry etc., I’m watching your second video and I’m awfully impressed. You go into details and explain them very well.
Subscribed. Keep posting these videos, they are gold.
Pozdrawiam.
Thank you. It means a lot. Will do my best to create and share even more material related content on this channel. Pozdrawiam :D!
This was very useful and greatly presented, barely any detailed info on this out there so thank you so much!!! I have found that when shooting some surfaces when the sun is very bright I would use the silver side of the reflector against the direction of the sun to cast light from it to the opposite side of the surface and sometimes it kills the harsh shadow, not as well as the flash but still!
Thanks a lot, btw. your solution sounds like a very interesting idea but I would affraid that the light reflected this way might be not consistent enough. I would rather use black side of the light reflector to absorb the light and its shape to cast a shadow and this way shot in a shade. I did it many times and it works great, the only problem is to hold it steady during windy weather.
Really awesome video. Everything is very clearly explained with great details, the annotated diagrams and high quality video footage make it easy to watch and follow. I also like seeing all the amazing scenery where you live, the drone shots look especially cool. No doubt the local people think you are doing something strange with so much odd looking gear! Great job as usual, thanks for sharing!
Thanks Barnyz :), appreciated
@@GrzegorzBaranArt it made my back ache watching it :0 You should get small lite weight Sony camera and small lens to go with it.
@@Barnyz :DDD
Your video are very useful and informative! Thank you to share your knowledge. It might not sound much, but talking about weight reduction, I took the habit to NOT wear my backpack while doing photogrammetry: this add to your weight on the back especially when you are bending just even a lit bit.
Thank you! :D Regarding the backpack and weight reduction, it all depends on the location and if you scan alone or in group. When I scan I am usually 100% focused on a subject and dont pay much attention to surrunding environment. I mean, even to the level where I was caught by tide waves a few times while scanning the beach sand. It takes a few seconds for someone to steal/grab a backpack, especially when they see that you are super busy. Photography equipment is usually perceived as expensive and is easy to re-sell, so a backpack full of it might be considered as an opportunity for some folks. Therefore, sometimes I do as adviced and leave the backpack on the ground, especially when I am alone away from people, but usually when I am not, and there are some people nearby, it feels just safer and easier to carry it on my shoulders. But as said, it all depends on the exact case, if I scan alone and how heavy is the current load - sometimes it is just the camera and the drone, sometimes it is just the drone, sometimes if I parked car nearby I carry just a single, small bottle with water, sometimes I carry more etc., especially if it is a full day of scanning. But you are absolutely right, keeping it on the ground makes the job less exhausting. Cheers!
Great video love the info you provided we just upgraded our camera to a r6 love the drone shots do you use a nd filter? Thanks for sharing👍
Thanks, doing my best :) No, I dont use any ND filter for the drone. R6 souds great, wish I can afford one :D. Probably my next after 80D dies is going to be 90D or R as Canon plans to end all DSLRs.
Great video and really interesting. I will be scanning a larger area outdoors soon and was looking for information like this. Thanks a lot! Unfortunately I don't have a ring flash. Can I use as well a standard flash like the nikon sb800 with diffuser cap?
Thanks. Yes, you can use standard flash lights but they wont do as good job as a ring flash. Many depends on the surface complexity. While it can work for flat surfaces, these which has some higher elements will get the micro direct shadows. Just put something like a pen and take a picture of it on a white background. If you get the shadow based outline it means that you need to compensate it somehow until it is gone. The ring flash iluminates the light from the lens point of view so any shadows are always invisible for the lens. By using a flash light mounted over the lens you risk getting some shadows depending on the distance to the lens and the surface. To deal with them you would need to use second flash mounted to the oposite side .. or even add a few more but this way you would simply mimic the ring flash. This is why we usually use ring flash for scanning, but standar flash based setup is of course possible.
You can also consider static flashes with very diffused light but I dont think it would work well for large areas. Also these would need to be very powerful to do the job.
Of course with more flashes or with the diffused one you would struggle with cross polarisation.
Great video as always, thank you very much. One question; do you think laser pointers may help distance checking while carrying flash without tripod or monopod. At 0:28 of Quixel's "Behind the Scans: Xeric Shrublands" video their rig has laser pointers. I thought these pointers can help keeping same distance and line during scanning. But I haven't tried yet.
I would say the sky is the limit here. I am sure laser pointers can help, especailly when you shot from such close distance like guys from Quixel do so you can clearly see them. Quixel guys seems to have slightly different approach in this video, but bear in mind that they use different equipment and I dont think everyone from quixel has access to this exact setup. In this video tho they use Elinchrom dual head flashes which have TTL function built in. It means that the flash power changes with the distance automatically. Also with such close distace they can use much lower output power. Using dual flashes makes sense as images arent full square but rectangular, also two flashes delivers the level of light which easily overpowers even direct sunlight on a desert. Its noticeable especially when you shot from such close distance. To make it lighter and work longer they carry a battery, which is quite large and heavy in a backpack. But this is much more expensive solution to AR400 .. I would say 5 times more expensive and honestly.. I cant imagine holding it myself high up front for a few minutes :). Just try to rise your hand over your head and keep it high there for 1 minute and you will get what I mean. Last but not least, there are features in photoediting software which can bring all images to similar tonal level and make dark images brighter and bright darker.. and as long you have the data to use and didnt under or overexposed any you can tweak them without actuall loss of any data. So slight distance changes from the camera to the flash arent a big issue and are fully manageable. So presented quixel approach seems to better to mine but also has its own pros. The price is a big one in her. It makes sense to pick their approach if you scan really a lot every day but at the end .. its just the final result what matters. I am sure quixel plays with stuff the same way we all do since its still uncharted territory .. and every way to improve it is a good one. So I would definitelly consider laser markers if they can help you in anything. Hope that helps :). Cheers!
Hey there,
Would love a course on how to use steps past Agisoft. Like how to create texture maps, normal maps, etc. I’ve watched your other videos before on how you do it but that assumes you’re familiar with each software and what each step is doing.
Hey, its a very good idea. I was even considering to cover it in a series of videos .. one per exact channel but still not sure would a single one covering all of them woouldnt be better... but I put it quite far in my 'STUFF TO DO' queue as I prioritised other videos. Especially that I covered some texture details in a few of my videos already. But thats correct, I didnt create a dedicated video just about texture channels and I plan to do one, just not sure what format should I pick for this one.
@@GrzegorzBaranArt I think it would be better to focus on individual videos to explain the what, why and how of each step after successfully rendering in Agisoft. You seem to use 2 pieces of software made by the same company (a big company like adobe or something, can’t remember their names). Anyways, looking forward to seeing more. If you want to put them on a paid platform let us know, happy to support :)
I don't know if youtube show you statistics of what part of the video the users see, but if does, you'll see the path of a madman going back and forth at 29:23. I know you have shown before differences in between polarized images, but this composition you've made is beautiful. I guess having the xrite in the middle helped you while editing to achieve perfect exposure in the comparison, but how different were the raw pictures and the camera settings? (Dude, I would love to see those raws... I could set those as wallpaper one in each monitor). I guess all filters you can buy differ in some manner and not "proper for scientific purpose" but are yours in between exposure steps or are they so close that you can barely notice? Just curious.
Anyway, as always I think your videos are invaluable for cg artists.
Yeah, filters matter. Some atr thinner, some thicker so some lets more light int while sone less. Also filters, even the top brands differs within the same type regadring the color. So if you pick the same filter from the same manufacturer made in a different time, they will still differ. But the color tint isnt important for filters really. Whats important is lack of any color, brightnes and perspective distortion across the filter surface. It is more important for the one mounted on a lens, and doesnt matter too much for the one mounted to the source of light.. as long it keeps the flat angle. Images I used for this comparison were color calibrated, these are not pure RAWs. So I corrected the White Balance to avoid any color shifting and set the lowest brightness level using for each using grayscaled darkest XRite color checker's clip value (BLACK: RGB52,52,52) to give each the same luminance starting point. This is the only that way to compare these images :D which makes sense for me. Its not a hack tho but part of standard calibration procedure as it is much easier to do it this way, then spending hours messing with the camera setting to get identical histogram coverage. This is why we shot full RAW as this way we have plenty data to work with without any quality loss. If I ever make a video about actual color calibration I should cover all the details of what I am talking about and compare different luminance distribution curves for polarised and non polarised approaches. Cross polarisation really messes luminance part as XRite Color Checked wasnt designed with cross polarisation in mind and captures differ a lot and make calibration much tougher and less accurate from the luminance point of view. Hope that helps :). Thanks for such kind works about my vids, trying to do my best with each and it means a lot knowing that it wasnt waste of time and someone actually found something useful in here :D. Cheers!
I love these videos, so busy these days making art there's little time to get out and take pictures/do photogrammatry, your channel is inspirational.
BTW I got the same ring flash and polarizer from Nz - if you have any transportation tips that would be great. Concerned about damaging the film.
For camera shopping I highly recommend looking at the Canon R5/R6. Mirrorless - with the in viewfinder greater range of information such as instant histogram, is so much better than SLR.
Thanks a lot Dan. I am afraid of lens incompatibility if I move to Canons R series. Also considering Sony A7RIV as an option but I am not sure. I feel like Canon is just superior to SONY as a still camera (I had an opportunity to shot with SONY too). I carry filter mounted on a flash in my backpack. As you can see on the video I arranged a dedicated space for the flash in my Mindshift 30L backpack [37:50] so it feels very safe and well protected there.
Well as you probably know you can use a lens adapter with your old lenses, or just sell them. But the new R series - or any mirrorless - are really a treat. Lighter, smaller and the viewfinder with histogram as I said (and true exposure simulation). Canon's coming out with new lenses quickly that are really amazing (as usual). I love the new primes - 35, 50 and now 16. The _only_ thing that still catches me is the lag when initially looking through the viewfinder, still not used to the small lag. Also the battery life isn't as good, they're really power hungry.
@@GrzegorzBaranArt Not later after you got your 80D I got a M6Mk2, that would be equivalent to a 90D (bigger diff apart from mirrorles to dlsr would be on video, so non important to this conversation).
Coming from the 700D I already had some lenses and the feeling of a rough outdoor camera. The M6 came with a 18-135 ef-m but with a cheap adapter I can keep using ef-s lenses, who I like much better than the Ef-M (although they work fine in my non technical opinion) maybe because they feel design for outdoor use. The same for the body, I feel more comfortable getting the 700D (and most likely the 90D) closely to dirt (both cases taking proper care). In the other hand I don't miss the shutter at all, can't say the same from the eye viewfinder but I've learn to live without it (too expensive for this model). My overall opinion is that compact mirrorless are best suited for "city" and "home", meanwhile, The R series are quite dope (as much as expensive), probably the adaptors are not almost affordable and they are getting better everyday. I hope that Canon finally comes together and develop some aps-c classic rough bodies to meet in the middle. In any case is not worth to talk about recommendations now, your camera really looks like you take good care and those mf shutters live long, when time is due you'll do your own research for products that don't exist yet. What do you think are your dream specs? Mine would be (not talking video now) 50mpx for around 1000$. Hope my camera live long enough to have that available (btw, the 700D still live through mud and pain non problem).
@@UnrealVirtualUniversity My dream specs? A very good 24-70mm zoom lens which doesnt creep when facing down :).. I love the premium one (24-70 mm 2.8 GM) for Sony mirrorless cameras even tho its really heavy. Regaring the camera itself.. I just dont know. I am considering switch to SONY but from the other side, all my lenses are CANON and CANON is a very good brand too. So if I have to pick a camera today, I would probably pick older and heavier: Canon EOS 5D Mark IV and a good 24-70mm zoom lens.
Regarding the pixel resolution, I have found that for photogrametry, large images slows me down and becomes a bottleneck in reconstruction. Photogrammetry benefits from having more images even in lower resolution then less images taken in higher resolution. Even if I use Sony A7R4, I still set it on ASP-C Crop mode. High resolution makes total sense if you want to create very high resolution stuff.. like 16k textures. I have found that 24-26Mpx is totally enough for any 4k or even 8k materials. So I always prefer a better and brighter lens with less blur or any if supported by the flash :) as this one really quarantees lack of blur due to really short exposure time.. to any higher image resolution. Image resolution really matters for any single image based reconstruction technique only. Because by covering 2by2 meters of any surface taking 200 images with 24Mpx you have really 14x14 images with 6000x4000px. If you get 50% overlapping for each it would give you 14x3000x2000px = 42000x28000 px actual texture resolution. Its a lot since I usually need just 4096x4096px out of it. So the key in here is the actual micropixel blur caused by long exposure, aperturesetting and lenes distortion. if we blur jsut 2 pixels, we lose the effective resolution by 2. If we lose 3 of 4.. we limit the effective resolution 3 or 4 times which in worst scenario for 24MPx sensor with 50% overlapping would mean 750x500px = 10500x7000px and in this case even if it is enough for 4k texture, its definitelly not nough for 8 or 16k anymore and this is where the image stabilisation, good lens.. and what is the subject of this videoo.. flash come in handy, as with the flash we usually dont lose any sharpness. So if you have place to store a lot of data, and hqve quick camera and super fast SD cards to avvoid buffering during capture. And if you consider future reconstruction when 16k becomes a standard, shoting in higher available resolution makes sense. But as long you need to sacrifice anything, imo it doesnt have such high priority and I would pick a better camera with better lens and lower matrix resolution in Mpx. Imo 26-42Mpx is a totally enough and safe range for years to come. Of course I might be wrong and thats just my private opinion. But this is why I am considering 'Canon EOS 5D Mark IV' which is an awesome, full frame camera with 26Mpx resolution only.. and I blieve the quality output this camera offrs, is the reason why it keeps the price even years after being released and is still comparable to all new mirrorless counterparts. Hope that helps :)
Anyway.. I am still not 100% sure what camera would I pick today if I can any.. and its a very tough choice as each choice has some pros and cons. Cheers!
@@GrzegorzBaranArt You've make me thing about lens creeping. I made back in the day lens rings for follow focus in the 3d printer. I nade multiple of them to be able to control zoom rather than focus in the gimbal and I've had to think about it, but this rings probably could help to lock the wheel adding something else... apparently they use some kind of rubber band but doesn't always work, maybe a combination of two rings and a elastic band with some theet should do the trick.
your videos are so good! thank you so much. I don't know if you have already covered this in one of your videos but how du you create the roughness/specular map? I've seen some tricks for statonary setup but I especially wonder how to create those maps for a mobile setup. For example if you do photogrammetry out in the street of objects that are made out of different materials that are more or less reflective, how can you caputre those informarion? The only thing I can think of is taking two pictures from every position, one with cross-polarized filter and one without. But is there not another way, where you can be more mobile, because if you do it with this method, the two pictures have to be made frome the exact same position, which means you would need a tripod.
I've seen setup from quixel megascans where the just take picutres with the cameras hold by their hands. Do you have any ideas how they create the specular like this?
Thank you and you are welcome. I was planning to recird a video about roughness at some point, after the one about color calibration but I dont have much time recently and it takes me really a lot of time on research and experiments before any of these happen. Roughness is a very tricky subject and similar to color, there are no an easy, 100% way to make or even measure one. So it is very benefitial to understand what roughness really is and how shader expects to use it. I usually generate roughness manually using captured data - and the way to generate one depends on the data available. The way with cross-polarisation works to some degree, but also isnt perfect and has some flaws. It definitelly helps to read reflectance levels by substracting cross polarised data from pararel polarised one and use this information when creating the final map. But as you said, for this technique to work you need to take two images from the same spot - one cross and one pararel polarised.
Thank you for this video. It is so helpful. I am a Sony A7IV camera user and wondering what might be compatible hardware for the cross polarization setup, specifically the synchronized flash setup. In the video you use a Canon setup with a Riko 400 and XT 32c + xt16 receiver. I am inexperienced in synchronized flash systems... Would you know if the XT32c and XT 16 are incompatible with Sony cameras? Or should I buy for a specific "Sony compatible". Prior to trying to buy the XT32c I was unaware that camera brand might affect compatibility with the XT trigger/receiver. I had purchased an xt16 receiver before realizing it may not be compatible or even if this part will work with the Godox 400 (Riko 400)... I know your setup doesn't require TTL (nor would I buy a part for that feature) but your setup does require a faster than 1/250 flash... I purchased the Godox 400 being in the US. But for the flash trigger/receiver and being a Sony user, I wonder if a: Godox XProS TTL Wireless Flash Trigger for Sony Cameras would be compatible with the setup (although I can't seem to find a receiver for it)?...it seems to be the only Sony compatible part that fits the spec of speed. In general I am just not sure what flash trigger/receiver is compatible or if your recommendation is cross compatible. forgive the specificity of this post, although I would appreciate any feedback. Thank you again for your videos! They have helped refine my practice more than any other channel !
Hey, any wireless Godox trigger should work. You just need make sure, that you purchased vershion for SONY hot shoe. Usually when you shop and you see any transmitter, you should select the camera you want it for. So all of these you mentioned has version for Canon, Nikon, Sony etc. I recently purchased PRO ST-III Plus 2.4GHz Radio Frequency TTL Flash Trigger with High-Speed Sync
(amzn.to/3r41dcb) and I use it on a daily basis. When getting a receiver - this small jingle you plug into the flash, you just need to be sure it has the same frequency.
I suggest to watch the other video I made where I show more details about these: czcams.com/video/REA3XNgUMJg/video.html
You dont really need HSS as it limits the flash speed significantly after the first burst (delay between every next image is longer). Also AR400 doesnt support TTL feature but honestly, I think its good to have these as an option if you ever consider swap the flash to another one.. this is what I use since I use different flashes for different purposes (you should see what I am talking about in my incomming video).
I used to use SONY version of 'PRO ST-III' with AR400 and SONY A7R4 without any issues, cant see any reason why others would struggle. Just make sure you picked a SONY connection version.
awesome videos, definetely underapreciated.. btw are you only using agisoft, I did some comparisson, and reality capture consistently gives out better scans.. it solves stuff that agisoft doesn't .. on all occasions, also seems that RC detects different components automatically, so in a way you can put in all the different scans and it does a sort of default batch processing of all objects you did .. in any case I feel you would have a much higher success rate, it's sort of cheap to get started with it anyway, great vids, very informative
Thanks a lot, appreciated. Yeah, I use Agisoft Metashape on a daily basis, because it outputs very good results, has no any scan limits and is way cheaper. I purchased a license a few years ago for 150USD and I still use it as all updates are free. I also use 3DF Zephyr from time to time but Metashape is more consistent and iutputs denser geometry. I was planning to make a comparison video between: Meshroom, Metashape, Reality Capture and 3DF Zephyr but it stucked in my video queue :). I guess sooner or later I should make one but have a few interesting already in production now.
@@GrzegorzBaranArt yeah a comparison would be great, I just don’t get why I get fails with same data on metashape, reality capture supposedly doesn’t use point cloud but only depth map.. a speed test would be great as well.. there were some 10$ free credits going around where people were promoting and doing tuts on RC - you could probably get a sponsorship by them, might be worth a shot ;)
@@robob3ar Will do. Metashape since 1.6 also use depth maps for reconstruction. This software was way behind RC but it has changed a year ago. Now it is fast, doesnt need unlimited resources, can do the job on an average notebook now. RC is still faster to Metashape but reconstruction quality is very similar. RC used to be better but it isnt anymore imo.. and its way more expensive now.
Hey Grzegorz, amazing tutorials as always :) Do you know if the Pixapro 400 works with focus stacking?
Thank you. I am not sure how to answer your question as focus stacking and the flash are 2 totally separate subjects. Every flash which can be sync with cameras shutter release can be used for image/focus stacking. Its more about the rail and the camera mounted on it then the camera and the flash. But, yes, AR400 like every other flash light or LED light can be used to iluminate subject for image/focus stacking. Of course a lot depends on flash placement, working distance of lens used, focal length and the size of the subject.
@@GrzegorzBaranArt thanks! I guess I didn't compose my question correctly :) Have you tried your ar400 with focus stacking? I have an external flash and have issues when trying to use it with focus bracketing. It works well otherwise
@@eveb6325 I still dont fully understand the question but as said, any flash light which can be sync with shutter release should work with focus stacking, unless we are talking about different things. For focus stacking I use automated rail which when moves the camera forward, after certain time I set outputs the signal to the camera to release the shutter. Camera outputs signal to the flash and triggers it so the flash flashes when camera takes the picture. Next the automated rail moves the came ra forward .. waits until it stabilises for the amount of time defined by me, and entire preocess repeats over and over until the stacked capture is over. The only issue I can see here is the size of the flash itself, as for really tiny subjects it is simply too large, therefore crosspolarisation wont work, also if the distance to the subject is too close (and it happens when you use microscope objective based setups or high magnification lenses) it wont even illuminate it as the lens might cast shadow on it. So there are a lot of variables to consider, but yes, any flash works with focus stacking as why wouldnt it? Hope that makes sense, unless we are still talking about different things.
Honestly, I dont use flashes for focus stacking anymore as flash needs the mechanical shutter to be released. Each camera has limited mechanical shutter life span - usualy to about 100k-150k captures, therefore I do my best to use a digital one instead. But as said, camera wont trigger flash for digital shutter, and if it somehow does, you will get weird lines across the image. Maybe this is the issue you have and you need to switch your camera to mechanical shutter mode? As said, its really hard to help without knowing more details.
So to answer your question, yes, I can do focus stacking with AR400 and any other flash as well as LED lights etc. I guess I should make some kind of video on the subject of stacked captures and extreme magnification ones, but I really struggle with time. Dunno, maybe I should set a patreon or webpage and share all my experimets there in plain text and images only as it would be much easier? Will think about it.
Anyway, yes, I did. All my magnification shorts are based on image stacking - some were stacked from thousands of images just for a single frame
Thanks so much Grzegorz! My mirrorless canon just has some troubles with the external flash. I did change to a mechanical shutter, however it still doesn’t trigger it when I try to do focus stacking. I’ll continue to test and maybe I’m just missing something very simple 🤦🏽♀️😀
Re: Patreon - yes I would totally support you and so will other happy users! Can’t wait!
@@eveb6325 Yeah, it must be something very simple - probably in transmitter setup or channel sync between transmiter and receiver. As said, digital/silent shutter mode in camera intentionally doesnt trigger flash as it would cause visual glitches - because of how digital shutter works. This is why cameras are designed to trigger flash in mechanical shutter mode only.
Good luck with finding what prevents your AR400 from work. Yes, it should work like any other flash.
Hey there, thank you very much for all the explanations! It's a treasure for all of us involved in photogrammetry:)
I have a question about the flash. I'm in Italy and the Godox AR400 is out of production, it only can be shipped from usa.. Do you have a valid alternative? Thank you and keep going with videos!
Can be the Godox Kit 2 Flash Macro Mf12 a valid alternative? It's not a ring flash and I don't know if cross-polarization is possible with it.. It's a mess
@@brandogallo3466 AR400 is available under many brands like WistroAR400, PixaproAR400, RICOAR400 and many more. This number comes from the flash output power which is 400W. The MF12 has 12W as it was designed for macro. Its a great flash and can be polarised.. just in a slightly different way, but its not the best choice for photogrammetry. You would basically need 40 of them to match the output power of a single AR400. There are other ring flashes available but they are more expensive, AR400 was the cheapest one in this class.
@@GrzegorzBaranArt thank you for the answer Grzegorz! Unfortunally Wistro, Pixapro, Rico and Lightspeed are all unvaible in my country... I tried to ask to some professional photography shops and seems there is nothing like them avaible.. The only solution seems to buy from usa or china. If you know other brand let me know please, in the while thank you so much and keep going with videos, I really appreciate them!
Hey Grzegorz! Thank you so much for your cool tutorials! Always high quality content and full of very usefull information, really appreciate that!
I have started with 3D (Blender) about 2 years ago and enjoy every second of creating new stuff. Now i wanted to start photoscanning my own textures and came across your video when searching for tutorials.
Now I have a couple of questions regarding the creation of pbr materials.
At the moment, what i quite don't get, is the step of baking from high poly to low poly.
- since it says baking from hight to low, does that mean you bake geometry as well?
- And if so what would be a good amount of polys for the 2x2 square to bake on?
- Or does low poly mean just the flat 2x2 square (only the 4 corner polys, to be considered as low)
- i just understand at the moment why there is a need of polys on the 2x2 target plane when we are baking only images (albedo, ao, bump, normal etc.)
- and can i set this target plane up in blender as well? (And then bring to substance for baking)
Would really appreciated it if you could help me with understanding this process a bit more indepth!
Thank you very much and have a nice day!
Loris
Thank you,
- PBR baking is a process of projecting 3D data into 2D form (set of PBR textures)
- amount of polies for high poly depends on the texture resolution you want to bake. By setting the density you need to make sure that there is always enought data to fill each pixel of the texture. Keep in mind that its all in 3D so themesh density has to be considered with 3D in mind. So if you do simple math for flat surface, for 2048x2048 texture you would need at least 2048 multiplied by 2048 pixels which gives you about 4mln polys as a minimum. In this case you get 1 poly per pixel. Since it is 3D I would multiply it by 2 at least which gives at least 8mln poly for 2k texture. It is because lets say, that you have a pebble.. edges of it is vertical therefore it gets some vertices just to cover a single pixel etc. So for grass reconstruction, even 100mln poly dense mesh might not be enough while for flat wall, 5mln would be fine.
To be safe and make sure that I always have a lot of information to bake from I aim for 100mln poly meshes with 16k albedo maps used to carry color information... for 4k texture sets.
- yes, you can set your target plan in Blender or any other app which works for you, just make sure that export setting is correct so its not rescaled or rotated durign the export.
Hope that helps
@@GrzegorzBaranArt Ah i see, great advice with this calculation, thank you!
- so generally, the higher poly the better, just for the sake computer performance you would choose a lower poly count?
- and do i get this right, the plane to bake on does not need any poly? its just for baking on the different maps, so no subdivision or so, just a basic standard plane?
@@lorisdiminico yes. Denser mesh needs more resurces (RAM, processing power) and more time for actual reconstruction. Its not worth to build 1bln poly heavy mesh for 2 or 4k texture. Regarding the low poly plane.. yeah, it doesnt need to be dense. It can be made of 2 triangles. But I have found that it might be worth to get a slightly denser one for complex shapes for better alignment.. usually for cliffs etc. .. as the low poly plane is just the canvas for the baked texture and what matters are just its normals/direction and efficient UV projection so the baked texture isnt stretched. So low poly model is a kind of window we project the highpoly data through. Hope that makes sense and I didnt went to away with this comparison ;)
@@GrzegorzBaranArt I think i slowly get this. yeah i think with 1bln poly mesh my computer would go up in flames hahah
Thank you very much for replying so fast and giving all these highly valuable information! Really appreciate that! So now i just have to wait till the snow is gone and then im out for my first photoscanns.
Thank you very much for your help and have a nice day!
You mentioned that you use a circular polarisation filter on the camera. Why did you not use a linear filter, is there some kind of advantage? also do you know if the polarising filter on the ring flash is linear or circular?
The difference between linear and circular polarisation filter is that linear filter works both sides while circular is just one sided. Circular to be one sided needs another polarisation layer which twists the light. In result, circular polarisation filter works as polariser only when seen through from one direction, and doesnt if inverted. Circulars polarisation filters for cameras cannot be mounted in a wrong way as they have a thread on one side only. One sided (circular) polarisation prevents issues with double cross-polarisation when light gets reflected from camera's mirror therefore, its better to use circular polarisation filter for camera to avoid blacking out an image in certain cases. It the case for any camera systems with mirrors - usually for DSLR cameras.
All Scan-Space filters I used had linear polarisation filter. Hope that makes sense :)
Grzegorz Brzęszczykiewicz
How should carry a flashlight and camera in a single bag? Are there any recommendations for a backpack?
Hey, I made entire video about backpacks :). After all this time from the video release I havent change my mind and still fully recommend 'MindShift FirstLight'. Here it the video I mentioned: czcams.com/video/KoAn1jDH4ss/video.html
I would consider also 40L version of the same backpack for longer trips as I usually use 99% of 30L available space. Since its fully adjustable I change the layout depending on what equipment I carry. You can see the layout I use to carry a camera and the AR400 flash at [41:18] of this video. Hope that helps. Cheers!
Hi Grzegorz, how do you manage such fine detail and high poly on 3D scans? my workstation is pretty decent (6 cores, GTX 1080, 24g RAM) yet every time I use metashape it runs out of memory if i try to get more than around 16M polygons or run mesh refinement...
Do you use dense cloud based reconstruction or depth map based one? The depth map based reconstruction doesnt need so many resources as the cloud based one. 16M polys isnt much for GTX1080 and 24GB of RAM to handle, you should not get into memory issues with this setup unless you are doing something crazy ;) like forcing super heacy reconstruction manually etc. Can you please tell me at what reconstruction stage and what reconstruction setup Metashape tells you that it lacks of memory to proceed? Do you use recent Metashape version?
@@GrzegorzBaranArt thanks for your reply! I'm using metashape pro 1.8.3, and the memory overload happens either while generating dense point cloud on highest quality or running photoconsistent mesh refinement even just on high setting. The latest model I tried to run on was a small church with ~600 photos in 4k resolution. Maybe that's too many pictures? I tried to use fewer images but then I lose details on things like railings and bas-relief. But you're absolutely right about depth-map reconstruction, I've been able to scan an entire village with it and it only took a few hours to process. I also just wanted to say your channel has been a massive help getting my business started, I've been creating photogrammetry scans since I was 13 years old but your advice really brought me to the next level. Now I'm creating made-to-order materials and high definition art scans :) I probably owe you a few beers lol
@@K3Techs As adviced, please dont use dense cloud based generation anymore as since 1.6.2 Agisoft introduced a depth map based reconstruction which is way more faster and efficient option. They left dense cloud generation mode as a legacy for those who wants to use it for some reason, but in practice they stopped improving it as a tool :). Cheers Pierre!
Hi
I just wanna ask for what exatly do u use these scans?
Hi, here is my portfolio: www.artstation.com/gbaran
Basically PBR materials are useful when applied ot any geometry in 3D scenes when they are done you simply drag them and drop on any 3D object. It is useful in gaming industry - and this is how I use them on a daily basis since I work as Expert Materials Artist at Ubisoft - but also in movie industry. Scanning allows us to speed up the process and getting the best possible quality at the same time.
Materials can also be sold separately and there are a lot of material libriaries available, like mine: www.artstation.com/artwork/NxNE41 but also like Quixcel Megascans, textures.com etc.
All of these are useful to build a 3D scene and in case of scans.. make it look real easily.
Usually you see these materials when you play a 3D game or watch a movie which contains scenes made in 3D (VFX) which often dont or cant exist in reality. Most content of Avatar, Star Wars, Dune was made digitaly this way. Hope that makes sense.
i have a somewhat probably normal situation here....right now i only own one lens. the sigma 1424 for sony e....wondering if this ring flash would work using one of the filter holder systems such as haida or nisi....curious what your opinion on the matter says. thanks homie.
To be honest, I have no clue. To be 100% sure you would need to check manual and compare hole and lens front diameters. Also bear in mind, that even if these are fine, if you plan to use polarisation filter, its reduces effective diameter even more. I used AR400 with the polarisation filter from Scanspace mounted with Sony24-70mm GM and Sigma 24-70mm lenses and while Sony lens still had some space left - not much, Sigma 24-70mm was basically touching the polarisation filter and sometimes when I was unflolding it to zoom in, it was pushing polarisation filter off the flash. So in practice to I had to mount the camera first, and mount polarisation filter after. But even if tight, both were fine. So if I have to guess, I would say that even if tight, you still should be fine, as I believe that gap size has standard diameter as Godox wouldnt want to eliminate part of the market by making it to small... but its a guess and I would measure it first or ask in the store you are planing to purchase from. Hope that helps :D
@@GrzegorzBaranArt amazing. thanks brother.
Same experience for me when using a flash versus not, some people are curious and some are fearful. I have had 3 people over 4 trips become aggressive toward me, one saying he was going to smash my camera. You could take non flash photos all day long and have nobody even look twice as you, but the flash upsets their monkey brain I guess.
I had never met anyone behaving really aggresive directly towards myself during the scanning. Maybe except some kid who threw a rock and hit me while I was in the middle of capture :). But I met a lof of curiosity though .. even one guy made additional half mile to walk next to me when I was scanning the grass for this video. Unfortunately he walked in front of the camera so I had to re-record the content. Was considering to add him to this video tho so funny it was.. but I decided not to and focus on the subject. Regarding aggression.. I have found seaguls are freaking agressive recently towards my drone like never before ..my drone gets attacked by at least one seagul every time I scan something on the coast :D
@@GrzegorzBaranArt May the gods of birds have mercy on your drone.
świetna robota. napisałem do ciebie na instagramie w związku z podobnym problemem. Mam nadzieję, że uda Ci się odebrać moja wiadomość. pozdrawiam ciepło
Odpowiedzialem na Artstation :)
Hi, Is it possible to simply change the battery when the flashlight overheats?
Hey, I am not sure what you mean: you can change battery anytime, usually when its out of juice. If you meant battery removal to force overheating counter reset, I dont know as you can reset overheating protection simply by turning the flash OFF and back ON without waiting 10 minutes for it to cool down.
I do that sometimes when I am in a hurry, or when there is just a few final shots left to finish the capture and I already know I am gonna move to another location after so the flash will get time to cool down anyway. Its also external conditions depentend, so when I shoot in cold windy weather which helps to keep the flash at lower temperature it is ok to override this protection when needed. When I shoot in a hot sunny day, I would recomment to check flash temerature with hand before even the overheating protection kicks in and let it cool down when needed. AR400 has is a quite simple and cheap flash and a lot depends on user. As far as I remember the OFF/ON overheating protecion workaround works just 2 times in a row and the 3rd time forces you to wait 10 minutes before you can use the flash again anyway.
To be honest, I never used the second reset as I I dont want to damage the flash. This protection is built for yours and flash safety. Its just an electronic counter which doesnt take any temperature reading into consideration as there is none - hence the manual option to override it.
Bare in mind that the temperature doesnt affect just the bulb, but also electronic components inside. So I wouldnt strongly recommend not override the protection more than 2 times even if it is possible and even if you shoot in winted. But I never tested if it can be done through battery removal and dont have any plans to test it as I need my flash.
Hope that makes sense :). Cheers!
@@GrzegorzBaranArt Thanks a lot for your answer,Love you!
Regarding the battery, I thought it (battery) was overheating and not the lamp, so I thought to replace it if it overheats)But now I've found out that the lamp itself is overheating and it doesn't make sense.
I have 3 more questions and I will be very glad if you answer:
1)When taking a portable photo in the sun, when the AR400 lamp overheats in 40 photos, it would be better to find another option.I found out that the Quixel(Epic Games) team uses the ELB 500 TTL, it is quite expensive, but the problem is not that, but that I did not find how to attach this lamps to the camera and I will have to develop and order a mount(for rig) (or ask for its parameters from Quixel) which could be a problem. Do you know any better and more powerful analogues of the AR 400?The price is not very important)
2)Also, for fast studio photogrammetry, I decided to use a continuously rotating stand and continuous series of photos to scan a large number of objects faster.This requires a very low shutter speed (1/4000;1/8000) since the object will be spinning continuously and I do not need it to be at least somehow lubricated.To do this, I will need to buy 3 Godox QT 600 or 3 Godox QT1200 (2 in front, 1 on top) the question here is whether there will be enough light (taking into account polarization) for a 1/4000 / 1/8000 shutter speed, I will test it in the studio where such equipment already exists. In your opinion, will this idea work?
3)I'm thinking of buying a Sony A7R V with 61 megapixels, is it a good choice for photogrammetry (I need 8k textures)?Maybe I don't need so many megapixels and I should buy the something simpler like Nikon D 850 with 45 megapixels, it will be 2 times cheaper.
@@mrlogo3733 no probs
ELV500TTL is superior to AR400 because it outputs more light and has TTL which gives advantage when it comes to outdoor captures without fixed distance. I never used it tho as it was too expensive for me and AR400 was good enough for the job. I had a feeling that Elinchrom was also providing a handle kit with their product but if not, you might need to develop your own custom handles. To be honest, nothing stops you to develop your own rig using whatever is out there on the market. For example use multiple AD200Pro flashes.. each outputs up to 200W and have TTL so when you combine 4 of them you get 800W and TTL etc. I would say, sky is the limit here.
Regarding the object movement during capture - everytihng depends on how much detail you want to get from your captures. If you aim into the highest level of detail, the subject should be still during the capture, and there is even some delay recommended to make sure all imcromovement is gone too. The smaller the subject and the higher the level of detail you expect to get, the more relevant it is. If you aim just into the shape, you can even get reconstruction from video. With the object sitting still you can get a better depth of view etc. but as said, it all depends on the subject type, size, capture contitions etc. and sure, you can capture things when they move if well illuminated and you are fine to sacrifice some quality. Its all about the balance and when you want to get from it.
The texture resoution from photogrammetry captures doesnt depend on matrix size, because you capture many images which next get combined into a single one. Sometimes image size can become a bottleneck when it comes to data processing. Its always better to get more smaller images than less larger, therefore, camere lens and sensors physical size are more important to image resoution. Yeah, Sony A7RV is a good camera for photogrammetry.
I cant tell you about your shutter speed as it depends on camera setting, distance to the subject and amount of light, but in certain conditions it is certainly possible to shot at 1/4000 or 1/8000. Btw. bear in mind that flash duration on its full power takes about 1/300s, therefore you wont be able to utilise full amount of lught it outputs in 1/4000sec. and you will need to compensate for these. This is why turntables stops and delays shutter after they did... to compensate all of that. But as said, it all depends on what you want ot get from your capture.
did u get any new tripod or any new gear in 2024?
if yes then please mention them in the reply
It depends for what, For surface scanning I use the same Tripod and monopod but I upgraded my camera to CannonR In a meantinme. I also upgraded the flash transmiter to a better one, but it doesnt make much difference. I purchased another tripod with reversed column for photometric stereos scans - I covered it in detail in my video about photometric stereo scans. I also purchased some Sirui monopods but I use them mostly for 'content creation to hold lights and cameras which record what I do' :D
Hope that helps
What is "black treatment"?
I guess I was talking about 'BLACK' slider during image preprocessing stage in DxO Photolab - this feature increases luminance of darkest areas. The darker the pixel, the more impact it gets. This is the easy way to get rid of or at least reduce power of shadows and flaten the luminance cross-image consistency :)
@@GrzegorzBaranArt Thank you!
Cyborg
Cheers! ;P
please add some gaps between sentences of narration
hey, I would but some folks requested to remove them to shorten my videos :). It is actually a lot of additional editing work to remove them all but I will do some research consider to bring them back in my new videos.