Focus calibration highlighted potential lens problem

johnnypanic

johnnypanic

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Recently purchased, Focal pro, to calibrate my Sigma 150-600 contemporary. As I have the Sigma dock, I was able to calibrate at 16 combinations, of focal length and distance. All seems fine, with a few variations, of a few fine tune points here and there.

Also decided, as I have the software, to calibrate some of my other lens. Firstly, the Tamron 24 - 70 2.8 and the Tamron 70 - 200 2.8. This is where the problems begin :eek:

On the 24 - 70, fine tune values were +4 at the 24mm end and - 5 at the 70mm end. Also tested at 50mm, which gave a value of -3.
Even more problematic, is the 70 - 200, which gives a value of +5 at the 70mm end and - 18 at the 200mm end!

These were calibrated, with my D610, so will run the tests again on the D610 and also run on my D500. But, if the variances are as dramatic as this, what are my options?

Thanks in advance for any guidance.
 
I would take Focal with a pinch of salt.
I had to get a refund on my version due to some really weird inconsistencies.
 
Bigfungun said:
I would take Focal with a pinch of salt.
I had to get a refund on my version due to some really weird inconsistencies.
Click to expand...

Anything specific? I had researched a bit, before buying the software and most reviews, were quite positive.
I'll run the software again, to see if it gives approximately, the same results.
 
Perfectly understandable that you may get variations at different focal lengths, if you mainly use a specific focal length adjust for that, otherwise take an average.
Caveat: make sure you use a good target and excellent light on it.
 
johnnypanic said:
Anything specific? I had researched a bit, before buying the software and most reviews, were quite positive.
I'll run the software again, to see if it gives approximately, the same results.
Click to expand...

I carried out the tests 3 times to ensure continuity and ended up with 3 different sets of results.
I gave up after that and used my trusty Lenscal thingy.
 
I get very consistent results with FoCal. Usually the resulting analysis is a micro adjustment within +\- 5.

An adjustment of 18 on canon would be huge - how do your current photos look on the 70-200 at the long end? Would checking your setup for the test - target, distance to target and lighting?
 
Bigfungun said:
I carried out the tests 3 times to ensure continuity and ended up with 3 different sets of results.
I gave up after that and used my trusty Lenscal thingy.
Click to expand...

Think this confirms that I'll need to run the tests, a few more times, to confirm. Had hoped, that the Focal software, would make this focus testing easier and quicker :confused:
 
newbie1 said:
I get very consistent results with FoCal. Usually the resulting analysis is a micro adjustment within +\- 5.

An adjustment of 18 on canon would be huge - how do your current photos look on the 70-200 at the long end? Would checking your setup for the test - target, distance to target and lighting?
Click to expand...

I had thought, that it would need adjustment at 200, but nothing as severe as -18. According to the software, target, distance and lighting were all good.
 
johnnypanic said:
Think this confirms that I'll need to run the tests, a few more times, to confirm. Had hoped, that the Focal software, would make this focus testing easier and quicker :confused:
Click to expand...

This is why I stopped using FoCal. Everytime I ran the calibration I got different results.
I use Dottune now.
 
:agree:

+ 1 for Dottune

GC
 
I gave up with FoCal - used mainly to test 300mm and 600mm lens - and went back to the Spyderlenscal, which is far more easy to use and understand
 
Looks like I'm going to have to do more work and try another system. Ahhh well, so much for Focal, making the process easier and quicker :eek:
 
This is the problem with zoom lenses, and and area where Canon trump Nikon as they allow different fine tune adjustments at each end of the zoom I believe. I've tried all kinds of lens calibration techniques and still find the ruler at 45 degrees/spyder lens cal the best for me. However, what I've also learnt is that if on the whole you are not getting noticeable front/back focus then don't bother as, from my experience, setting fine tune does make the AF less reliable. It's sharper when it nails it, but it does have more focussing errors (although still very few). I used to go through the process of checking all of my lenses, now I don't bother unless I see a clear issue as there are too many variables that can lead to focus errors and you're never going to get it right 100% of the time, especially with zooms.
 
I find that my lenses seem to adjust themselves ........ I take 1 or 2 OOF, (out of focus) shots and then what do you know ........ the next 25 are sharpe ....... then after that a few more OOF and back again to sharpe images

mystery!!!;)
 
johnnypanic said:
Looks like I'm going to have to do more work and try another system. Ahhh well, so much for Focal, making the process easier and quicker :eek:
Click to expand...

Eyes are a good tool to use ;-)

I too dont bother with Focal any more. As others have stated, you get a different result each time, i also find the software to be buggy.
 
Buy a mirrorless system and be done with AF fine tune forever lol

So glad ive never to deal with it again, was my biggest annoyance with dslr
 
F/1.4 said:
Buy a mirrorless system and be done with AF fine tune forever lol

So glad ive never to deal with it again, was my biggest annoyance with dslr
Click to expand...
The new on sensor phase detect in continuous AF is still prone to focus errors unfortunately, I just don't think it's as prevalent.
 
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