Calibrating Lenses Questions

arshuter

Senior Member
I've seen a few youtube vids on this. My questions; is it really necessary? All the videos are for prime lenses how do you do zooms? and what if you get clear images on the bottom end and not the top, say a 70-200 take good pics to 130 but blurry on up, if this is even possible. Just too much time on my hands I guess.
 

Andy W

Senior Member
The zooms that I have calibrated were checked at four distances with four focal length settings at each distance. I've done three Sigmas and two Tamrons. It is a pain in the #$$ but it helps.
 

Horoscope Fish

Senior Member
I've seen a few youtube vids on this. My questions; is it really necessary?
Ultimately only you can decide that for yourself. Personally, I check all my lenses for front/back focus. Some have needed adjusting, others have not. My personal opinion is that calibrating focus is definitely worth the effort.

All the videos are for prime lenses how do you do zooms? and what if you get clear images on the bottom end and not the top, say a 70-200 take good pics to 130 but blurry on up, if this is even possible. Just too much time on my hands I guess.
Specifics always depend on the lens in question. Nikon camera bodies only allow for a single, global adjustment for a particular lens, be it prime or zoom, so you have to use an averaged adjustment. Many (but not all) Tamron and Sigma lenses are able to use their respective "docks" which allow for correcting front/back focus at various distances and focal lengths.
 

Fred Kingston

Senior Member
To add further to what Pauls says... With zooms you average... I use Focal... which uses an algorithm to test at various focal lengths then tests and uses an average of those focal lengths... In your example, I would test at 70, 100, 150, and 200 and see which way THAT lens needs to be adjusted and then settle on that number.

Another method assumes you have a pretty good portfolio taken with that lens. Lightroom (and I assume other programs/sources) let you search through YOUR images and find the focal length that most of your images have been taken at... and then test/adjust for that focal length...
 

desmobob

Senior Member
I've seen a few youtube vids on this. My questions; is it really necessary?

I'd say it's certainly not necessary, but how could a person not want to at least check to see if their lenses were focusing as accurately as possible? :rolleyes:

Plus, it's a photo-related project to do while stuck at home...
 

DaveNewman

Senior Member
100% essential IN MY OPINION and this is why...

purchased the D500 and got my "old" 200-500 calibrated, to find out it was +14 (out of 20) out.... sharpest was found to be at 7.1 and f8 which is really no good for wildlife shooting, found out and testing on of Fstops the lens was at fault......

got a brand new lens (same one) go this calibrated with the camera and was +1 out and f6.3 to be at its sharpest. Lens now is stop on, also gave me a peace of mind knowing that all is good..

might cost, but i think its worth it
 

Woodyg3

Senior Member
Contributor
I have used Steve Perry's recommended procedure for auto-calibrating, which I know is only available on some cameras. Here's a link in case your camera is one of those, and you want to give it a try. It's pretty simple.

https://www.youtube.com/watch?v=5cHhrWF-pqM

Meanwhile, I will also say that I only calibrate if I notice that the lens is back or front focusing.
 
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