Bill_de Loc: US

I have done some reading on the subject. Although just because something is published there is no guarantee it is correct. There seems to be a general agreement. High resolution sensors above 12mp on crop sensors increase the need for fine tuning. Shooting at F4.0 or smaller decreases the need. If I ever find my images are not sharp enough I'll give it a try. One writer said + or - 5 is satisfactory, and only higher deviations will be noticeable.

I never shoot charts taped to a flat wall, so I figure that gives me a little wiggle room.


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Ratta Loc: California

A quick question: what do you all use to do your lens calibration and do any of you have a favorite AFTER using multiple methods. Thanks

TriX Loc: Raleigh, NC

Hello Susan,

Yes, the points on the graph show the acuity at various MFA settings before final correction - the final correction is the highest point (acuity) on the graph.

You can purchase 2 different versions of the SW ( https://www.reikan.co.uk/focalweb/ ). I would recommend which ever suits your needs and budget. After you down load the SW, you have an option of either purchasing a target or downloading and printing (which is what I do). You mount the target on a well-lighted vertical surface (wall) at the specified distance from your camera (depending on the lens FL) and after it prompts you to center your focus on the center of the target, the SW then takes a number of exposures. With each exposure, the MFA is changed and the camera defocuses and refocuses, a point is plotted on the graph, and the projected final correction is refined. At the end of the process (about 5 minutes), the final MFA value is determined - it's the peak of the graph where the acuity is the highest. Depending on your body, the entire process may be automatic or you may have to change the MFA between exposures (you are prompted both visually and audiably).

Let me know if I can be of further help.

Cheers,
Chris

Howard5252 Loc: New York / Florida (now)

If the body has a Fine Tune option ... the lens can be fine tuned to each body (that has the option) . It will take a little time and effort on your part but "Better to light a candle than curse the darkness". If your other bodies can't be fine tuned ... well, as you said "... it was a lesson learned".

mwsilvers Loc: Central New Jersey

Absolutely. Three of my current Canon bodies have the micro focus adjustment feature, but my Canon 60D, which was my primary camera at the time, does not. My Sigma 30mm f/1.4 predated the Sigma USB hub. At f/1.4 to f/2.8 it was way off, and at the time calibrating it with the camera seemed like the only option. On the other hand my Sigma 18-35mm f/1.8 was almost perfect on the 60D out of the box.

therwol Loc: USA

I bought a 70-200 f4 VR last year, and it has been my only lens so far with a focusing issue (On my D810). I went out in my back yard to try out the lens, taking pictures mainly of birds in trees, and every photo was out of focus. The lens was near focusing, and you could see it even without magnifying the images. I got a sickening feeling and had to make a decision, take it back or adjust the focus. I decided on the latter. It needed +6 at 200mm. I didn't do any formal testing at other focal lengths, but I've not noticed a problem so far. I think that this situation with lenses is ridiculous.

mwsilvers Loc: Central New Jersey

It not ridiculous. Its quite common and a result of manufacturing tolerances. That same lens on a different copy of your camera, or a different copy of your lens on your body might require completely different adjustments, or even better no adjustments at all.

romanticf16 Loc: Commerce Twp, MI

Use a relative's card at the public library.

romanticf16 Loc: Commerce Twp, MI

The Spyder may calibrate for lens color casts, but not focus.

romanticf16 Loc: Commerce Twp, MI

With that fast a lens I'd send camera and lens in for adjustment. It could be the mount surface of either?

mwsilvers Loc: Central New Jersey

More likely normal manufacturing tolerances. In any case if using microfocus adjustment fixes the issue, why would you want to send your camera and lens in for calibration? If you then try to use that calibrated lens on another body it would likely not focus properly. Most of the problems people have with focusing issues are not due to problems with the lenses but to the tolerance difference with the particular camera it's mounted on. That's the reason for the availability of the fine tune feature on the prosumer and above bodies.

therwol Loc: USA

I'm sure you've heard the expression, "If we could send people to the moon, we should be able to do X, Y or Z" I believe that a camera, regardless of the lens mounted on it, should be able to tell whether a picture (or the subject of a picture) is in focus when the picture is taken. If the current sensor arrangement allows for errors, then it needs to be redesigned. Do you remember the Nikon FA film camera from the 1980s? The lenses used in those days included older lenses that were modified with an AI aperture ring and AI lenses whose diaphragms were not calibrated with the precision of the AIs lenses that were current when that camera was new. To compensate for the inaccuracy of the diaphragms of the older lenses, the camera took a second meter reading after the aperture closed, and the shutter speed was adjusted to compensate for any aperture errors, resulting in correctly exposed pictures. Our newer cameras need to be able to see whether the image on the sensor is in focus and adjust the focus when it isn't. If that requires a bit of technology that doesn't exist at the present moment, then someone needs to work on it. I still think it's ridiculous to spend hundreds and thousand on lenses and have to adjust each one to compensate for errors in the way they focus.

mwsilvers Loc: Central New Jersey

Sending people to the moon costs billions of dollars. You can always buy $45,000 Hasselblads. I'm guessing they're made to tighter tolerances. But if you want affordable mass produced equipment there is a trade off in manufacturing tolerances. More precision always costs significantly more money.

tradio Loc: Oxford, Ohio

I did inquire a few years back about sending both lens and camera to Nikon and they estimated just over $400. I thought that was a little steep but, that was also a internet inquiry and not a person to person quote.
It's just like cleaning your sensor, if you are not comfortable doing it, take it to the "man".

Retired fat guy with a camera Loc: Colorado

There is no info on how to calibrate a lens. That's what I am looking to find out what and how to do.