Photoshop: Adaptive Wide Angle - Failed to Calibrate

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  • Updated 4 years ago
  • (Edited)
Posted this on the Adobe forums with no response for > 3 days ( Trying a different(?) forum to try to get different eyes.

I am using Adaptive Wide Angle in order to straighten some edges of some artwork photos. I am using the 'fisheye' correction. More often than not, I draw the line to use as my 'basis' and then when I drag the center point to have the curve match the one in the photo I receive this error message:

"Failed to Calibrate. You may need to adjust the constraint more precisely or try another constraint."

I have tried this on both 32 and 64 bit. I will say that it will work in some areas of the same photo, but not at the critical points where I truly need it. I have no idea what is lacking during the calibration, so I'm unsure what to adjust. Since my corrections are usually on the edge, I thought that may be the issue, but I added some whitespace around the photo and still get this error.

Any ideas? Is there a work around? What does it even mean (calibrate? 'more precisely'?)? I can supply a photo if needed.


Adobe Photoshop Version: 13.0.1 ( 20131024.r.34 2013/10/24:21:00:00) x64
Operating System: Windows 7 64-bit
Version: 6.1 Service Pack 1
System architecture: Intel CPU Family:6, Model:10, Stepping:9 with MMX, SSE Integer, SSE FP, SSE2, SSE3, SSE4.1, SSE4.2, HyperThreading
Physical processor count: 4
Logical processor count: 8
Processor speed: 3500 MHz
Built-in memory: 16269 MB
Free memory: 12914 MB
Memory available to Photoshop: 14660 MB
Memory used by Photoshop: 60 %
Image tile size: 128K
Image cache levels: 4
OpenGL Drawing: Enabled.
OpenGL Drawing Mode: Advanced
OpenGL Allow Normal Mode: True.
OpenGL Allow Advanced Mode: True.
OpenGL Allow Old GPUs: Not Detected.
Video Card Vendor: NVIDIA Corporation
Video Card Renderer: GeForce GTX 660 Ti/PCIe/SSE2
Display: 2
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Paul Benson

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  • confused

Posted 4 years ago

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First, I assume the photos on question are indeed captured by a fisheye lens (only its profile not supported by Photoshop), and the photos are uncroped (the lens axis projected on the photo center exactly). Otherwise it is expected that the calibration tool will fail (even it does not fail it will get wrong result).

Then, the calibration tool does not guarantee a successful resolution to the lens' focal length. It is more likely in certain cases the tool fails than other cases. This is because the following reasons (skip the rest of this section if you only want to get recommendations). First, no lens perfectly embodies a stereographic projection. That imperfection is the reason why Photoshop prefer a lens profile over use simplified projection model. Second, it is inevitable that errors are introduced when you align the constraint with a salient line in the photo. The solution of the lens focal length is much more sensitive to the introduced errors in certain cases (see the following section) than others. In such cases, a minor error would render the solving process fail.

The rule of thumb to avoid failure is
1. Make the constraint as far from the photo's center as possible.
2. Make the constraint and the line connecting the center of the constraint and the photo's center as close to perpendicular as possible.
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Paul Benson

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Thank you for the reply. Even though it does not fix my problem, I appreciate the knowledge you have shared.

It is not a fisheye lens, but the lens is known by Photoshop (EF-S18-55mm f/3.5-5.6 IS). It is the 'starter' lens that came with my SLR. Quick and dirty, but it does the job for this task (or so I thought). The pictures are uncropped. When I first start the tool, it will do an initial modification which actually exacerbates the distortion I am seeing and it makes the picture 'pinched'. That may be part of my problem, since I am actually trying to un-pinch the picture. As I said, it sometimes works, but I also get the error.

I am taking pictures of my wife's paintings which are on rectangular canvases. Therefore, it is easy for me to know what should be a straight line. Since I am trying to maximize resolution, I try to fit as much of the picture in the frame as possible; thus, I am definitely following your first rule of thumb in that the edges I am trying to straighten are very close to the edge of the picture.

I will also say that since I am drawing the constraint line from the artwork's edge to edge, and the artwork is fairly centered, then the center of the constraint and the center of the photo are close to vertical and horizontal.

I did not realize this tool was so closely tied to the lens. I thought the lens profile was used as a starting point, and then the rest of it was 'just math'. I believe I heard in a tutorial that this tool should work without a lens profile, so I may remove the meta-data and see what happens. I also have watched a few tutorials, and it just seems like people are straightening lines all over the image without incident. Granted, they are using pictures shot with a fisheye lens, but, it seemed to be a fairly 'fool proof' filter.

I know the lens I am using is not the highest quality, but I hate to shell out the cash for this task when Photoshop is so close to doing what I am hoping to do. I mean, it is literally just scores of pixels away from perfection (I am moving the center constraint about 50 pixels). I guess I was thinking the algorithm to remove fisheye would also be used to remove pinch (and it does, sometimes).

Again, thank you for your post.