Lens Calibration Questions

TheCheesehead

I have heard of people getting great results after sending lenses in with their bodies to get calibrated by Canon. Should I send in my 5D with 50 1.4 and 20mm 2.8? Would I see a marked improvement? Thanks!

Brett1000

TheCheesehead wrote: »

I have heard of people getting great results after sending lenses in with their bodies to get calibrated by Canon. Should I send in my 5D with 50 1.4 and 20mm 2.8? Would I see a marked improvement? Thanks!

I suppose the difference would depend on the degree of "mis-calibration". Have you done any focus chart comparisons ?

TheCheesehead

No I haven't, can you point me to some self-help focus charts? Thanks!

Projoe

I'm new here but wanted to put my to contribute to the discussion. Lens Calibration is really important and now that the major manufactures have given us the ability to do our own micro focus adjustments ourselves we don't have to send our lenses and bodies in for calibration unless they are completely off.

Most newer cameras which allow for micro focus adjustment in camera give you a +-20 calibration for front or rear focusing. There are a bunch of product on the market that help you to do own calibration. Focus Pyramid, Len Align, Spyder and a fee others.

Which ever you use, the beauty of simply attaching a lens to your camera and the camera automatically corrects for auto focus variances is simply awesome!!!

I'm in the car now but when I get back to the studio. I'll upload a few pictures of a 300mm 4.0 Canon L glass being aligned.

Helvegr

I've been thinking about doing this myself. I'm loving my new 50mm 1.4, but wide open the DOF is so narrow that even the slightest issue with focus would throw things off. Plus I'm getting the impression that it might be off just a little based on some pictures.

NeilL

Lens calibration via stationary, well-lit high-contrast targets in the exact focal plane throughout, at one focal length, or shortest & longest in the case of zoom, and with the camera on a tripod, with mirror lockup and remote cable release/delayed shutter is good to do, sure, and especially good for our need to have our gear in "perfect tune" before we do anything real with it.

But, with a moment's consideration, you will realise that the real world is likely going to challenge all those precious lab-perfect best case scenario parameters, and you're going to be fighting for focus against all the randomness out there and in yourself! With your photographer skills rather than with your camera-lens calibration!

So you're gonna still need experience and luck, but yeah it does often make some positive difference to do home calibration if there's a largish discrepancy. Anything larger than that should certainly be dealt with by the manufacturer.

Neil

Ferguson

Check out Focal: http://www.reikan.co.uk/focal/


It's a semi-automated program for doing the AF Fine Tune adjustment, and also in the more expensive versions have lots of goodies like testing accuracy of each focus point.

I used it for my Nikon D800 and was very pleased. With (some) Canon's it is even more automated as the canon firmware lets it adjust AF Fine tune from the teather.


PS. no relation to the author other than a customer.

divamum

+1 for Focal. It's wonderful and makes a tedious job a lot easier (and, likely, more accurate).

JayP

Looks great and very reasonably priced too. I tried Lens Align but too many opportunities for being out of focal plane. I like the automated aspect.

Demian

Yeah, Focal is nice. I picked it up recently, and it makes calibrating your own lenses SO much easier. A little expensive, but I think it's worth it, especially if you have a lot of lenses. It also makes it easy to quickly calibrate rented and borrowed lenses.

Helvegr

I sent the Focal people a message asking about the D4. It was mentioned that the D800 and D4 should support the manual adjustment, but they only have the D800 in their list when purchasing. Hoping the D4 is supported.

jmphotocraft

FoCal seems great, but I would not use it for any cameras it does not fully support yet. I've heard of some weirdness with the 5D3.

jmphotocraft

DIY Autofocus Calibration with Canon EOS Utility
Copied from here: http://www.birdphotographers.net/forums/showthread.php/58042-AF-microadjustment-tricks, in case that page goes away. I have used this method with good results.

By arash_hazeghi

There is a very convenient way to perform MA with Canon EOS cameras, all you need is a good sturdy tripod and head, a simple contrast target and a small mirror.

First find a target that has fine high contrast features, you can print an ISO chart, a dollar bill or even a map but the target has to be perfectly flat. Pin the target to the wall at a distance ~25-50 times the focal length, for a zoom lens choose the focal length that you use most often. First use the spirit level on the ball head to level the camera in XY plane. It is essential that sensor plane is parallel to target. To do this you can use a small mirror, tape it to the target look through the camera’s finder until you can see the center of your lens in the mirror and lock down your tripod. Optical axis is now perpendicular to target and you are done with the mirror.

You must have Canon EOS utility application installed on your machine, this is included with every canon camera, if you have an older version make sure to go to Canon’s website and download the latest update. You are ready for micro adjust now.
Follow these steps:

1) Connect the camera to your computer via the USB port, cancel any image download pop-up/application
2) Run EOS utility.
3) Click on Camera setting/remote shooting icon.
4) Click on Remote Live View Shooting this will open a new window with live sensor video feed.
5) Make sure AF is in phase detect mode (quick mode AF) that uses camera’s main AF sensor.
6) Choose the center AF point and make sure the white rectangle is centered on the AF point, this illustration is for 5DMKII, AF points pattern will be different for different cameras.
7) Click on magnifying icon for a full size view.
8) Click AF ON button the camera will now perform AF.
9) Click on a 200% magnification, you are now viewing sensor output at 2:1. Note it is essential that tripod be placed on a solid surface plus nobody should walk in the proximity of the setup or you will see vibrations on the screen!
10) Now click on the ( > ) or( < ) buttons to shift focus back or front one click at a time until image appears sharpest on the screen, notice the contrast edges, you want them as crisp as possible. Write down how many clicks you have moved relative to the center, infinity symbol indicates far direction
11) Repeat this a few times until results are consistent.
12) Each click on the ( > ) or ( < ) corresponds to one unit in the AF micro adjust scale in the camera.
13) Disengage LV by clicking close in the Zoom View and Remote Live View Windows.
14) Go to MA menu option in your camera and dial in the exact value noting the back or front direction.
15) Go back to step 3 and perform AF again, if image is already as sharp as possible when you click 200% you are done, if not iterate until you can repeatedly get the sharpest image. You can shoot test images and transfer directly to your computer.

Your camera and lens static AF should be adjusted with great accuracy now.

MomaZunk

Cool, I purchased FoCAL over the weekend and calibrated all my lenses with my camera. It really gave me some piece of mind since I have dropped a couple, and was wondering if anything was off. I only needed to adjust between -2 and +6 on my 4 lenses. Now I just need to do another check outside at longer distances for the 200mm range.
Data and graphs make us engineers happy.