How to Calibrate the 35mm Sigma Lens Easy
how to tune a Sigma lens on longer distances/infinity via the USB dock?
So I have a 2 Sigma lenses that I want to calibrate.
- 24-105mm
- 150-600mm
I've first tried calibrating the shorter of the 2 and while it's easy to calibrate if the distance is not far (.45m to .90m), I'm having through with the next 2 which is around 1.9m and infinity.
at 1.9m distance + no changes using the software + 50-70-105mm focal lengths, it's easy to easy the lens is front focusing. at 24mm focal length, it's impossible for me (and I'm near sighted) to see if the where the focus is. I made some adjustments on the 50-70-105mm focal lengths but because the depth of field is large enough that it's hard for me to completely say the focus is at zero.
at "infinity" distance (in my case, I tried around 4-5 meters away), the distance (at any focal length) is too great for me to see where the focus is.
I haven't looked at the 150-600mm due to lack of time (though I'm guessing I'll experience the same issue at the longer distances!).
Any ideas? Thanks!
Sony Alpha NEX-5 Nikon D7100 Nikon D750 Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF-Nikkor 80-200mm f/2.8D ED +4 more
(unknown member) • Forum Pro • Posts: 11,356
Re: how to tune a Sigma lens on longer distances/infinity via the USB dock?
2
MrJayViper wrote:
So I have a 2 Sigma lenses that I want to calibrate.
- 24-105mm
- 150-600mm
I've first tried calibrating the shorter of the 2 and while it's easy to calibrate if the distance is not far (.45m to .90m), I'm having through with the next 2 which is around 1.9m and infinity.
at 1.9m distance + no changes using the software + 50-70-105mm focal lengths, it's easy to easy the lens is front focusing. at 24mm focal length, it's impossible for me (and I'm near sighted) to see if the where the focus is. I made some adjustments on the 50-70-105mm focal lengths but because the depth of field is large enough that it's hard for me to completely say the focus is at zero.
at "infinity" distance (in my case, I tried around 4-5 meters away), the distance (at any focal length) is too great for me to see where the focus is.
I haven't looked at the 150-600mm due to lack of time (though I'm guessing I'll experience the same issue at the longer distances!).
Any ideas? Thanks!
1. Forget about measuring. Simply connect the lens to the dock, start software, look at the matrix. Screen capture it and print it. As you can see on top of the chart there are red lines indicating the distances.
2. Make a setup outside in a good light. Put your camera on tripod approximately where you think it should be and focus on your target. Take a look in the focusing window. There is a white line in the middle showing the distance. If it matches the red line in the picture you printed do nothing. If it doesn't move tripod and refocus until it does.
3. Don't use any software to do it. Software is designed for a single camera adjustment not the USB dock with multiple adjustments.
4. At MFD (Minimum Focus Distance) add few inches once you established where it supposed to be. Just for a good measure so lens can actually focus reliably.
5. Longer distances. If you don't have proper target you might not be able to calibrate because you need to look at large DOF and most setups don't have large DOF. The good news because it is a large DOF it is not so critical as at MFD. I built target myself to be able to do it. The ruler is 4 feet long at 45 degrees. The focusing target is 5x5 parallel to the camera.
6. Infinity. Mostly guess work because you can't make a target that large.
If you can find three buildings in a row and stand at 45 degrees at the distance indicating in the matrix chart you printed take a picture of the middle building and inspect it. See if the blur on the other two buildings is the same on both sides. A street island with trees in line might work the same way if you can stand far enough. The good news DOF is very large so don't worry about it too much unless you are a way off.
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Re: how to tune a Sigma lens on longer distances/infinity via the USB dock?
SushiEater wrote:
1. Forget about measuring. Simply connect the lens to the dock, start software, look at the matrix. Screen capture it and print it. As you can see on top of the chart there are red lines indicating the distances.
Thank you. I am using a lens calibration target I got from Amazon.
Sony Alpha NEX-5 Nikon D7100 Nikon D750 Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF-Nikkor 80-200mm f/2.8D ED +4 more
(unknown member) • Forum Pro • Posts: 11,356
Re: how to tune a Sigma lens on longer distances/infinity via the USB dock?
MrJayViper wrote:
SushiEater wrote:
1. Forget about measuring. Simply connect the lens to the dock, start software, look at the matrix. Screen capture it and print it. As you can see on top of the chart there are red lines indicating the distances.
Thank you. I am using a lens calibration target I got from Amazon.
Throw it away. It is designed for close distances only and that is why it is only 11 inches long. You can't calibrate infinity with it. You probably will not be able to calibrate some wide lenses with it either.
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Photography Director for Whedonopolis.com
Re: how to tune a Sigma lens on longer distances/infinity via the USB dock?
SushiEater wrote:
Throw it away. It is designed for close distances only and that is why it is only 11 inches long. You can't calibrate infinity with it. You probably will not be able to calibrate some wide lenses with it either.
what's the size of your calibration target (the DIY one you posted)?
Thanks!
Sony Alpha NEX-5 Nikon D7100 Nikon D750 Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF-Nikkor 80-200mm f/2.8D ED +4 more
(unknown member) • Forum Pro • Posts: 11,356
Re: how to tune a Sigma lens on longer distances/infinity via the USB dock?
MrJayViper wrote:
SushiEater wrote:
Throw it away. It is designed for close distances only and that is why it is only 11 inches long. You can't calibrate infinity with it. You probably will not be able to calibrate some wide lenses with it either.
what's the size of your calibration target (the DIY one you posted)?
Thanks!
The ruler is 4 feet. Target is 6x6 inches. It will calibrate everything but infinity.
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Source: https://www.dpreview.com/forums/thread/4491971
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