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Lens calibration issues ?
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Nov 30, 2018 15:35:50   #
abc1234
 
I have been using the Reikan FoCal and am still struggling with it after about 20 hours. Your must be fastidious about it and if you do not have the patience, I suggest that you forget about adjusting the micro focus. Once I get done with my tests of FoCal, I will post my results here.

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Nov 30, 2018 15:44:11   #
Dngallagher
 
abc1234 wrote:
I have been using the Reikan FoCal and am still struggling with it after about 20 hours. Your must be fastidious about it and if you do not have the patience, I suggest that you forget about adjusting the micro focus. Once I get done with my tests of FoCal, I will post my results here.


One of the fastest ways to use MFA was the "DOT tune method", but FoCal goes beyond that by analyzing the actual sharpness of the target at several MFA adjustment points. You need your target steady, at the proper distances and well lit, either buy a target or print in high res on photo paper.

Once you get the procedure down, it becomes fast and easy. You do need plenty of room for telephoto lenses though :)

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Nov 30, 2018 16:39:56   #
abc1234
 
Dngallagher wrote:
One of the fastest ways to use MFA was the "DOT tune method", but FoCal goes beyond that by analyzing the actual sharpness of the target at several MFA adjustment points. You need your target steady, at the proper distances and well lit, either buy a target or print in high res on photo paper.

Once you get the procedure down, it becomes fast and easy. You do need plenty of room for telephoto lenses though :)


Taking the actual calibration pictures is the easy part. Set FoCal on automatic and just wait. However, setting up everything which includes moving my pc from my upstairs office to downstairs where I can get enough distance for my 150-600 lens is another story. Tethering the camera is very much better than shooting untethered. I originally worked outside but the sunlight was changing slightly but caused very poor results and reproducibility. Getting enough light on the subject plus using the right tripod were other learning experiences. Now that I have figured out what it takes to get good results, I will give it a final go.

One thing that I may have learned is that for my Sigma 18-300, FoCal works well at 18 but is useless at 300. The lens is probably of too low quality at 300 so I will try again at 200. Fortunately, the rest of lenses are of much better quality.

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Nov 30, 2018 16:53:53   #
Dngallagher
 
abc1234 wrote:
Taking the actual calibration pictures is the easy part. Set FoCal on automatic and just wait. However, setting up everything which includes moving my pc from my upstairs office to downstairs where I can get enough distance for my 150-600 lens is another story. Tethering the camera is very much better than shooting untethered. I originally worked outside but the sunlight was changing slightly but caused very poor results and reproducibility. Getting enough light on the subject plus using the right tripod were other learning experiences. Now that I have figured out what it takes to get good results, I will give it a final go.

One thing that I may have learned is that for my Sigma 18-300, FoCal works well at 18 but is useless at 300. The lens is probably of too low quality at 300 so I will try again at 200. Fortunately, the rest of lenses are of much better quality.
Taking the actual calibration pictures is the easy... (show quote)


Ohh, I hear ya about the setup... I have just enough room inside to do up to a 300 mm lens....above that I need to head outside. I could do my 70-200 & 16-300, but cannot fit my 150-600 inside.

When I did the DOT tune method I would set up my 170-500 and my 150-600 in the family room and shoot to the woods edge... but DOT tune did not rely on any off camera analysis.

IF warmer weather returns :) I will set up my 150-600 outside and see what happens ;)

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Nov 30, 2018 17:11:51   #
abc1234
 
Dngallagher wrote:
Ohh, I hear ya about the setup... I have just enough room inside to do up to a 300 mm lens....above that I need to head outside. I could do my 70-200 & 16-300, but cannot fit my 150-600 inside.

When I did the DOT tune method I would set up my 170-500 and my 150-600 in the family room and shoot to the woods edge... but DOT tune did not rely on any off camera analysis.

IF warmer weather returns :) I will set up my 150-600 outside and see what happens ;)


Welcome to the club Don. Much harder and less clear in reality. Unfortunately, my training is in science so I am a bit anal about method and interpretation. What is DOT? I tried SpyderLensCal and similar approaches and found them unreliable.

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Nov 30, 2018 17:25:37   #
NormanTheGr8
 
Dngallagher wrote:
Reiken’s FoCal does a great job, even tests to find the sharpest aperture of each lens, which might not be f/8 :)



Another FoCal fan here the software even tracks settings and changes made for future reference

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Nov 30, 2018 17:28:56   #
stangro
 
Nikon ONLY allows calibration at one focal length on a zoom lens. Unless all your intermediate focal lengths are front or back focusing the same, the recommendations I have read are to leave it be (unless you shoot primarily at one focal length - like primarily at 200mm, for instance, then calibrate it for that zoom length.

I have the same lens as you, and I have resisted a calibration attempt on it, or my other zooms for that matter. I only calibrated my primes (the ones that needed it).

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Nov 30, 2018 17:36:40   #
Dngallagher
 
abc1234 wrote:
Welcome to the club Don. Much harder and less clear in reality. Unfortunately, my training is in science so I am a bit anal about method and interpretation. What is DOT? I tried SpyderLensCal and similar approaches and found them unreliable.


DOT Tune is just adjusting MFA based on live view and matching it to the viewfinder view, basically using AF in live view, then making sure that in viewfinder the focus dot lights up - by adjusting MFA you get viewfinder focus dot matched to live view AF.

http://1000wordpics.blogspot.com/2013/09/how-to-use-dottune-af-fine-tune.html

Many many videos on the DOT Tune method, for Nikon or Canon - as long as the model has MFA.

BTW - On my Canon 80D, DOT TUNE came up with the same settings for my Tamron 16-300 as did FoCal. BUT FoCal has that nice official looking documentation it provides for each lens when finished ;)

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Nov 30, 2018 23:15:54   #
aubreybogle
 
I am also about to embark on thisReikan FoCal adjustments process using a variety of Canon lenses from Kit to Ls and a TAMRON 18-400 and SAMYANG 2.8 14 MM. I purchased the latter two very recently because of their reasonable prices, generally good reviews, and I just wanted to evaluate them (unscientifically) because I was curious. Initial casual shooting indicate they perform very well. Maybe not as well as a roughly comparable L, but satisfactorily nevertheless. I will also report back.

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Dec 1, 2018 00:55:35   #
GENorkus
 
abc1234 wrote:
Welcome to the club Don. Much harder and less clear in reality. Unfortunately, my training is in science so I am a bit anal about method and interpretation. What is DOT? I tried SpyderLensCal and similar approaches and found them unreliable.


I'm interested in a good marked area too. Just got a 1970-ish 500mm f 4.5.

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Dec 1, 2018 09:16:37   #
abc1234
 
GENorkus wrote:
I'm interested in a good marked area too. Just got a 1970-ish 500mm f 4.5.


Do not understand what you mean. Please clarify.

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Dec 1, 2018 09:34:52   #
GENorkus
 
abc1234 wrote:
Do not understand what you mean. Please clarify.


I plan to just calibrate by the value marked on the barrel to actual length. Simple enough. That way I can focus in lower light conditions just by dialing it in.

Did that on my nifty 50 and found the marking were excellant to within a foot at 30feet. My hassel now is that 500mm lens' minimum focus is 30 feet and much more distance is needed.

With approximating, I found my 500mm to be about 50 feet off the marked distance at 600 feet. I'll need to check that with a bit more accuracy.

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Dec 1, 2018 12:27:49   #
abc1234
 
GENorkus wrote:
I plan to just calibrate by the value marked on the barrel to actual length. Simple enough. That way I can focus in lower light conditions just by dialing it in.

Did that on my nifty 50 and found the marking were excellant to within a foot at 30feet. My hassel now is that 500mm lens' minimum focus is 30 feet and much more distance is needed.

With approximating, I found my 500mm to be about 50 feet off the marked distance at 600 feet. I'll need to check that with a bit more accuracy.
I plan to just calibrate by the value marked on th... (show quote)


Do you not have autofocus?

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Dec 1, 2018 12:44:02   #
GENorkus
 
abc1234 wrote:
Do you not have autofocus?


No. Auto focus wasn't invented back then for the common person. 100% manual.

Sometimes I use the markings as a poorman's distance finder.

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Dec 1, 2018 12:52:16   #
abc1234
 
GENorkus wrote:
No. Auto focus wasn't invented back then for the common person. 100% manual.

Sometimes I use the markings as a poorman's distance finder.


Got it. Thanks.

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