DSLR Lens Calibration - Why It Is Necessary and How It Is Done
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- čas přidán 3. 07. 2024
- Calibrating DSLR lenses is a necessity and if done correctly, it will give you confidence that your DSLR will get the focus right - every single time.
This video provides you with all the insights you have to know to correctly calibrate your DSLR-lens combination.
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Video Content:
0:00 Introduction
0:37 Importance of Calibration
1:46 Calibration Process
7:51 Test for Focus Shift
9:45 Calibration Intervals
10:34 Conclusion
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Written Article: www.thomaseisl.photography/te...
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#dslr #lenscalibration #phototechnique #focusshift #spyderlenscal #photographytechniques #autofcus #autofocuscalibration #thomaseisl #thomaseislphotography
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I encourage you to take a look at my written calibration guide for further reference:
www.thomaseisl.photography/technique/dslr-lens-calibration
Thank you for your tutorial! it's very helpful.
Great!
Very useful. Vielen Dank.
Great! So good to hear!
.... 10 / 10 + .... excellent
Thank you very much!
You've touched on just about every aspect that is important in this one video! 🤓
(You might want to reveal though that Mirrorless shooters won't have this problem)
I'm putting it on my list for interns etc.
Ah, many thanks! That is great to read!
Of course you are correct about mirrorless. Interestingly, certain camera-lens combinations might require calibration on a mirrorless as well - e.g. Four Thirds to Micro Four Thirds OM-1
Thanks for sharing this! Personally, I have always shot with mirror-less systems for my personal work and now I have an education job where I am now shooting with DSLRs to document school sports and other activities. While I was aware of the need to calibrate the lenses, I thought I could live with the slight inaccuracies...NOPE!
Yep, I know exactly what you mean. I had the same "journey" - DSLRs need calibration. When they are calibrated, they are amazing!
Thanks for sharing that!
I wish I found this one year ago. I had a severe focus shift on Voigtlander SLIIS 28mm and 90mm.
The problem was very noticeable at mid range, about 5 meters : it was impossible to get sharp images.
But I did not know of focus shift, found no clear explanation. On exper forums, no one was able to point me to this, so I think it’s largely unknown and misunderstood.
I ended up selling the lens, because I thought there were defective and could only be recalibrated at the factory.
I replaced them with SLII versions, which have been fine as-is.
Thanks a lot for tgis tutorial.
I'm glad that you found it informative!
I've had some unnerving "encounters" over the years as well - only after understanding why the electronic rangefinder of the DSLR was fooled I was able to properly calibrate these lenses.
Interestingly, in 99% of the cases everything is alright. But there are these rare cases that need special attention and then you are out of luck if you don't know the underlying optical phenomena.
I'm glad that your new lenses are spot-on right out of the box, because that is how it should be!
Thanks for the contribution, Jean-Christophe!
Also, some zooms have some focus difference depending on the range, for instance I have a tamron 17-50 2.8 that I adjusted for 50mm but would front focus beyond -10 when on 17mm. I had to send the lens to tamron for a repair, it's a lot better now. I think some bodies allow for autofocus adjustment at different focal length but that's unfortunately not the case with my Pentax K3 iii.
Yes, this can be an issue. Some lenses can be configured via USB (dock) to migrate such issues - or by sending the lens to the manufacturer as you did!
I tried this and I am really not sure it helped with my zoom lens. Maybe I need to try again. Good video and good clear instruction/demonstration. Thank you.
Thanks! The problem with a zoom (depending which one it is) is that the focus can shift throughout the range, so it might be correctly calibrated at one distance and wrong at another.
Question: for an 85mm 1.8 at what distance should you calibrate ?
I recommend 2m, and after calibrating it, test it at 1m and 5m for accuracy! Then you should be good to go!
Great video! Not sure if you can offer any advice but I own both the 40mm and 58mm voigtlanders. When I attempt to calibrate them using the fine tuning tool on my d810 and 850 they both read as the same lens making it impossible to store 2 different tunings. Have you come across this issue?
So, it took me a while, I checked my lenses for this behavior as well. Here is what I found out: it seems, that all Voigtländer lenses have the same ID, which results in the the Nikons mistaking them for being the same lens. On my D800, the first lens you set a correction value for is the one that will be registered. So even the 58mm might be labeled as 40mm in the AF fine tune menu. I've tried different tricks, but it seems that there is no way to resolve this apart from setting the correction value manually when you change between these lenses. Or, you can take a look at my mastering manual focusing tutorial, as you won't need the electronic rangefinder after mastering this technique - no need for setting the AF fine tune for MF lenses when you don't use the ERF
@@ThomasEisl.Photography Thank you! I thought I was going crazy and couldn't find anything about it on the internet. I will most certainly watch that video! Thank you again for trying to figure this out.
Most welcome!
This is very detailed and informative! Thank you! One question if I may. There are much cheaper kits than the Spyder. It is also possible to have a home made one. Are you aware of big disadvantages of using cheaper models or even home made kit?
Great to read!
You can definitely use a cheaper alternative or even a tilted ruler. It is essentially the same thing, it really comes down to usability.
I also highly recommend taking a look at MTF Mapper with its custom charts. It allows you to calibrate the AF in very advanced ways - for free.
Hope this helps!
@@ThomasEisl.Photography Thank you for your help!
You sort of did not explain how the calibration is actually done. Eg how you interpret the measuring you do on the calibration target to set the actual value in the AF fine tune menu. So the ' why it is necessary' is spot on but the 'how it is done' is only vaguely explained.
Thank you very much for offering constructive criticism!
When you perform an action so often you risk to not mention the seemingly obvious, which might not be obvious!
I invite you to read the written article as it might be helpful. Also, if you've got a specific question, I'm happy to answer.
Thanks again and cheers!
Some prominent CZcamsrs advise against people calibrating their DSLRs because it’s claimed they tend to screw it up. Thoughts? Thanks
Oh, I'm totally pro calibration - if you know how it is done, and you can always reset the calibration.. I'd even consider it essential when shooting DSLRs especially when you run into issues in practice.
@@ThomasEisl.Photography Thanks for the reply, although I’m sad to add to my extensive to-do list…
I had some spare time during COVID and actually got into some depth on this subject with my Canon 5DSr and 5DmkIV.
I did hours and hours of test shots, and more hours of detailed analysis , and my results were, well inconclusive.
Today, I always use the micro-adjustments in the OFF position, which is where I obtain the best results.
I'm not saying this is the correct approach for everyone, but in my situation this whole thing proved to be a huge waste of time - and mooney too, because I bought these accessories.
I have only the best lenses from Canon, and I have paid the price for this. Perhaps the Quality Control on these high-end lenses includes calibration obviating the need for this adjustment.
I don't know, and I certainly won't predict results for anyone else, but in my case, having purchased the top-of-the-line products and used them with care, this adjustment proved unnecessary.
Thank you very much for taking the time to share your experiences!
If the focus works - you should not change a thing. I completely agree. Canon has very good lens profiles that automatically compensate for focus shift and more. Thanks to this technology, once a lens is calibrated (at the factory) things are usually fine.
Maybe you will need the calibration tools later, good to have them around just in case!
The in-body callibration for Nikon only has room for one plus or minus value. But I you have a Sigma Art or Tamron G2 lens you can set multiple values for multiple distances and multiple focal ranges ( the last only with zooms of course). This can result in 12 or 16 different values for one lens. For that you must have the usb lens docks. Whished that Nikon lenses had this feature.
Thank you for the comment - yes, Sigma really outdid themselves with their USB-Docks and the accompanying calibration options.
I only owned one Sigma art lens TBH and I did not calibrate it to the fullest extent (although I had bought the USB dock) as it was working just fine,, but the usefulness of this feature for the demanding user is clearly there. The true peak of DSLR performance and reliability is possible with their lenses for sure.
Thank you for sharing your thoughts and your continued support of the channel!
@@ThomasEisl.Photography 👍
@@ThomasEisl.Photography
Calibrating wide aperture lenses does make one appreciate mirrorless all the more..
Can you calibrate older zoom lenses…like the Nikon D 80-200 2.8 ?
Yes, as long as there is a CPU. However, keep in mind that there could be slight focus shift across the zoom range. So the calibration is only valid for a certain distance and f stop. In practice for most situations, this is however not an issue.
making sure the sensor plane and calibration plane are on the same level is the issue. This is an inexact science and for me it makes the whole process inexact
Well, it is a bit of a hassle, but it can be done ☺️ just give it a try and follow my tips, it will work out.
Focusing using the image sensor should be the most accurate. It's the focus when using the viewfinder you have to worry about where the prism system is now involved and not the image sensor.
Sorry, I don't quite understand. Could you rephrase that, please?
I do not believe alignment is always called for. Sometimes, yes, especially with 3rd party lenses. For example, I have 8 Sigma EF mount lenses (zooms and primes) I only had to microadjust a 35mm prime. If you use only one camera body, it's much easier and more accurate to do adjustments on a dock than in camera. Of course, if, like me, you use several bodies, the dock method won't work. It's also a royal PITO to adjust something like a 150-600 on the dock because you have to calibrate for different focal lengths at specific test distances....And that cannot be done in body.
True - some lenses are just fine as they are. And yes, calibrating lenses like the 150-600 is really crazy in practice haha. Thanks for sharing that. Best, Thomas
Don’t forget mirror slap. My Nikon D600 in quiet mode produces sharp images better than regular mode. Mirror slap on some cameras could be an issue.
Thank you for pointing that out, you are completely right!
I don't have much time but I'll try to address where I see you're going wrong.
Before you read further, you may not have the adjustment available to you but the good news is that you can do this all for FREE - no purchase necessary.
Firstly, keeping things simple, if you have a focus issue, it's usually with a specific lens/body combination (If it is with all lenses - service will restore operation) and it's going to be worse at some distances and with certain lighting situations. Why? You've seen chromatic aberration cause some light frequencies to focus closer or further with different glass - usually magenta and green casts - the sensor may get confused. This means that there is a correct MFA adjustment for each distance and lighting situation which MAY be different. To complicate things more, there's the problem of focus shift - where the calibration is different for each aperture used.
Next, when using the display to focus - you don't have MFA adjustment issues as it's the camera image sensor that is focusing - as opposed to light from the backside of your mirror getting reflected onto the AF sensor - lens, body, mirror, sensor - all move in relation to each other so errors can get compounded - or in some instances, or the errors can also cancel each other out.
This is why the feature is deep within the menu system of pro lenses - a work-around if you have to shoot through the viewfinder. Personally, I'd rig up a tablet and focus through that if I was shooting stupidly wide apertures and focus is critical - or just use the camera display. Because of focus shift, your image may still be out of focus if you're not shooting wide open! I've seen Canon's old 50mm f/1.8 shift massively when stopped down to f/2.8!!
Just as an aside, the Old Canon 50mm would also sometimes focus short and sometimes far - there was a literal spread! you can't MFA for that!
Next to check calibration, all you need is a ruler, some tape and a cereal box - maybe a book to put the camera on.
If I remember right, the distance Canon recommends to MFA each lens is 50x the lens focal length - but that's a factory specification. For me, it's the right value for the shot - whatever that is. MFA your lens for the job at hand. Take a small target to check MFA when you're out and about.
Place the ruler at an angle that you can see with 15cm or 6" mark, level with the front of the cereal carton - just as you're doing with the target. For a fancy target just print a QR code and stick it on the box - it has plenty of contrast - no need to buy anything unless you are going to do this for a living...
Adjust as needed - compare live-view with viewfinder AF but also check you're at your sharpest for different apertures.
This can make focus through the viewfinder MORE accurate than live-view for some stopped down apertures - but it's no game-changer.
Your title is wrong. It's not usually necessary. It's more necessary for full frame lenses on APS-C bodies but honestly, use a work-around, choose a more appropriate aperture and understand what's going on rather than going with the belief that because you can micro-adjust it's going to be perfect.
With Mirrorless, there is no adjustment you can do - just flip up your SLR mirror and focus on your tablet, phone or the camera screen!
That's all.
cb
Did you watch the video?
@@ThomasEisl.Photography Yes, I did eventually. I had to leave and I was half-way through typing my notes and wanted to post them for you. Everything was satisfactory.
You only really notice focus shift in the first few stops of aperture - beyond that and you're going to have plenty in focus. Now if you had some way of setting MFA for an aperture 1/3 stop off wide open, that could help some lenses!
Frankly, the tone and lack of demonstration/interaction and engagement puts me off.
DSLR Lens Calibration - Why It Is necessary (It's not always) and How It Is Done (Spend money? Not necessary)
The point of my post was really to disprove your title (or was it clickbait?)
A useful video would address:
Do you have the capability in camera (most prosumer cameras don't - canon started with the 60D, 7D and 5D2?
When could it be useful? (i.e. when live-view and TTL focus produce consistently different results)
How to test this without spending money.
What else could cause such issues (You missed CA being a cause with some lenses)
Show some examples (and failures).
cb
@christopherberry8519 oh I don't do clickbait. I seriously think that checking a lens and calibrating it if needed is necessary for a professional. And that is where the title came from. Thanks for contributing.
Like Michael R. I understood the theory behind this process but since you're more of a Nikon guy naturally you couldn't show the method for us Canon users. Straight after watching this I watched v=aAiGyl5CKlQ which provided a simple method for Canon DSLRs. Seems they have an option called "AF micro adjustment" to correct any back- or front-focusing alignment issues, although the feature may only be present on mid/high/pro level Canon cameras and not on the low/entry level models.
I have noticed that some photographers and even manufacturers warn that a camera may be unable to focus at minimum range or infinity when AF tuning is applied, so maybe this is why it is limited to higher models, as your average camera user wouldn't use it and providing the option on cheaper cameras runs the risk of amateurs messing with settings they don't understand and end up harming their photos rather than improving them, since this is clearly a fairly technical process that requires the owner to know exactly what they're doing before going ahead.
I have to admit that I deliberately did not show the fine tuning process in detail, as the menus differ from brand to brand (Canon and Pentax are currently not in my household), but I rather wanted to share my best practices applicable to all brands.
So I'm glad that a fellow CZcamsr could provide the detailed process for your Canon cameras!
Interestingly, I was not aware of the close focus issue and I've never encountered it - but it makes sense, because if the correctional factor is set too high and the lens is adjusted for a longer distance, it would be only logical! I tend to calibrate my lenses for portrait distances (1-5m), so that might be why I did not encounter that.
For photographers like you, who know what they are doing and what they want to get out of their cameras, I encourage AF fine tune as it will help to improve the performance of the equipment (if found lacking in the first place).
Thank you for your comment and your continued, much appreciated support of the channel!
@@ThomasEisl.Photography Question - do vintage SLR lenses tend to have focus shift issues as much as modern electronic lenses? I suppose, if they did, you'd need to send them somewhere to be serviced, since they can't be corrected in-camera?
That is a very interesting point, the issue is as follows:
If you focus a lens by looking through the lens itself (like a classic SLR) the focus shifts but it does not matter as your seeing it and focusing on the matte screen anyways. It is "what you see is what you get". The separate AF module of an SLR and the way AF systems in DSLRs work are the reasons for the issues.
Actually modern lens designs (with less spherical aberrations) are usually less prone to (relevant) focus shift.
Did that make sense?
Also, I'd like to add that this does not count for focus shift stemming from stopping down a lens, but from "focus breathing"
@@ThomasEisl.Photography It did, thank you very much!
What a nightmare to do all that in order get the focus right. Your 'explaining' is not really clear either. I use my lenses with many different apertures and focal lenghts. Do You seriously suggest that I have to go through this whole procedure every time when I change aperture and focal length and ISO and God knows what? Many years ago I 'calibrated' a Pentax 40mm ltd.pancake lens by throwing it against my garage wall because it would focus shift no matter what I did and has ruined some photo outings. Luckily none of my many other lenses required such calibration on different dslr's. I would otherwise have given up photography altogether long ago.
Yes, lens calibration can be a bit tedious, but it is not as bad as it sounds haha 😆
Thanks for sharing your experiences, and sorry for the limited lens 🤯