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Reikan FoCal Pro Lens Calibration
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Nov 21, 2022 10:51:24   #
abc1234 Loc: Elk Grove Village, Illinois
 
I used this to calibrate my lenses several years ago but am now upgrading to the newest version. In addition to running on a desktop computer, it now runs on Android and IOS. It can also connect wirelessly via WiFi. The price is great, $99.88, down from $135.88. The simpler version is $89.99. A great price for an excellent product.

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Nov 21, 2022 14:32:08   #
Hanson
 
May I ask: How does it calibrate your lenses? What does it mean by calibrate?

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Nov 21, 2022 23:50:12   #
abc1234 Loc: Elk Grove Village, Illinois
 
Hanson wrote:
May I ask: How does it calibrate your lenses? What does it mean by calibrate?


Let me start with your second question. Lens manufacturers adjust the autofocus mechanism so that optics produce an image that is in focus at different apertures and distances. However, for some unknown reason, a user may find that when focusing a DSLR through the reflex system, not live view, even a brand new lens may not focus properly. You can expect this over time with a lens as the mechanical parts wear and fall out of adjustment. In these cases, the lens's sharpness depends upon the electromechanical mechanism that controls how the glass elements focus. Unless you compare the sharpness of your lens against another lens, previous test shots, or a standard, you may never notice the declining sharpness.

Calibration is the process of comparing the performance of your lens's focusing accuracy against that of an objective standard. If FoCal finds the performance can get better, then it will perform a microadjustment to the lens. FoCal tells the camera's onboard computer or the firmware in the lens (I do not know which) how much the lens must compensate for the wrong focusing.

I hope this answers your question without getting to technical.

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Nov 22, 2022 06:44:42   #
billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont
 
abc1234 wrote:
I used this to calibrate my lenses several years ago but am now upgrading to the newest version. In addition to running on a desktop computer, it now runs on Android and IOS. It can also connect wirelessly via WiFi. The price is great, $99.88, down from $135.88. The simpler version is $89.99. A great price for an excellent product.


Many experts caution against fine tuning a lens, or, if you will, lens calibration. Most calibrations can only be done for one specific distance, many, many folks who try to fine turn end worse off than before calibration.
Over my 50 years of professional photography I have never had to fine tune a lens, be it Canon, Nikon, Sony, or Hasselblad.
I now only shoot mirrorless, which focuses the image right on the sensor, no need for any calibration for any lens.
I caution anyone trying to calibrate, DO NOT DO IT.
Lots of folks here will disagree with my statement, but after 50 years of hanging photography, and after more than 500 weddings, I have never, NEVER, had any issues with not getting a tack sharp image.
If you know what your doing, you will NEVER have to fine turn a lens.
Goodbye.

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Nov 22, 2022 08:23:31   #
redtooth
 
Good information billnikon .

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Nov 22, 2022 08:31:51   #
agillot
 
Now , maybe you can answer that , if the lens focus at wide open , but let say you are shooting at f8 or 11 , even if you are slightly off at wide open , at 8 or 11 the added depth of field would take care of that ?????

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Nov 22, 2022 09:07:44   #
jerryc41 Loc: Catskill Mts of NY
 
I got a notice from them when they had the iPhone version ready, and I recently got an email telling me that the Android version is ready. Fortunately, I don't do any photo work with my phone.

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Nov 22, 2022 09:10:29   #
abc1234 Loc: Elk Grove Village, Illinois
 
billnikon wrote:
Many experts caution against fine tuning a lens, or, if you will, lens calibration. Most calibrations can only be done for one specific distance, many, many folks who try to fine turn end worse off than before calibration.
Over my 50 years of professional photography I have never had to fine tune a lens, be it Canon, Nikon, Sony, or Hasselblad.
I now only shoot mirrorless, which focuses the image right on the sensor, no need for any calibration for any lens.
I caution anyone trying to calibrate, DO NOT DO IT.
Lots of folks here will disagree with my statement, but after 50 years of hanging photography, and after more than 500 weddings, I have never, NEVER, had any issues with not getting a tack sharp image.
If you know what your doing, you will NEVER have to fine turn a lens.
Goodbye.
Many experts caution against fine tuning a lens, o... (show quote)


Bill, I respect your experience. Focusing manually or using mirrorless obviates the need for calibration. My much more limited experience did show that calibrating did improve the sharpness. This is all a matter of expectation and comparison.

By sharpness, I mean focusing accuracy, not the optics.

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Nov 22, 2022 09:13:55   #
abc1234 Loc: Elk Grove Village, Illinois
 
agillot wrote:
Now , maybe you can answer that , if the lens focus at wide open , but let say you are shooting at f8 or 11 , even if you are slightly off at wide open , at 8 or 11 the added depth of field would take care of that ?????


Good question. Yes, the increased depth of field may compensate for any focusing error. However, the maximum lens sharpness is often two stops down from the maximum aperture. As you stop down past that, diffraction decreases the sharpness. Just be aware of these issues.

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Nov 22, 2022 09:15:52   #
abc1234 Loc: Elk Grove Village, Illinois
 
jerryc41 wrote:
I got a notice from them when they had the iPhone version ready, and I recently got an email telling me that the Android version is ready. Fortunately, I don't do any photo work with my phone.


Jerry, what that means is that they have migrated the desktop program to those devices so that you can run the tests and calibrations from any Android or IOS device. The app is not for adjusting the device's camera.

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Nov 22, 2022 10:19:29   #
NormanTheGr8 Loc: Racine, Wisconsin
 
I used it with my 7dmk2 and was very pleased with the results ,over time things inside the camera and lens move ! I would check every 3 or 4 months

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Nov 22, 2022 13:48:34   #
MikeT9
 
No, it allows you to carry out the calibration using a mobile phone instead of a laptop, making the procedure more mobile.

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Nov 23, 2022 06:18:55   #
Architect1776 Loc: In my mind
 
billnikon wrote:
Many experts caution against fine tuning a lens, or, if you will, lens calibration. Most calibrations can only be done for one specific distance, many, many folks who try to fine turn end worse off than before calibration.
Over my 50 years of professional photography I have never had to fine tune a lens, be it Canon, Nikon, Sony, or Hasselblad.
I now only shoot mirrorless, which focuses the image right on the sensor, no need for any calibration for any lens.
I caution anyone trying to calibrate, DO NOT DO IT.
Lots of folks here will disagree with my statement, but after 50 years of hanging photography, and after more than 500 weddings, I have never, NEVER, had any issues with not getting a tack sharp image.
If you know what your doing, you will NEVER have to fine turn a lens.
Goodbye.
Many experts caution against fine tuning a lens, o... (show quote)


I also found this out.
I played around with micro adjustments just to see what would happen.
I found no improvement on several lenses so put them back to 0 where they were originally.
Saw the whole thing as a waste of time and effort.

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Nov 23, 2022 08:30:40   #
abc1234 Loc: Elk Grove Village, Illinois
 
Architect1776 wrote:
I also found this out.
I played around with micro adjustments just to see what would happen.
I found no improvement on several lenses so put them back to 0 where they were originally.
Saw the whole thing as a waste of time and effort.


Without knowing the experimental details and seeing the results, I would hesitate on generalizing from your experience.

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Nov 23, 2022 10:21:35   #
User ID
 
abc1234 wrote:
Let me start with your second question. Lens manufacturers adjust the autofocus mechanism so that optics produce an image that is in focus at different apertures and distances. ....................


That challenges common sense.

Heres how it works in various cameras that I use:

The lens manufacturer calibrates nothing, but does provide that lens elements can move when commanded to move by the body AF system.

The body AF system is informed by the sensor image data as to which way the elements should move, and as to when the motion must cease.

Nothing involved there needs calibration and theres no provision for tampering with its function.

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