Luminous Landscape Forum
Raw & Post Processing, Printing => Adobe Camera Raw Q&A => Topic started by: Pete_G on January 26, 2013, 11:48:37 am
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I think I kinda understand how this software works. If I create sets of 9 images of a test chart at various apertures, I can create a lens profile
that, I presume, LR and ACR can use, reading the aperture from the EXIF and applying the appropriate data for that aperture to create a lens correction.
But how does the focus distance work, since within the fairly limited restrictions of shooting test charts the focus distance can only change by a small amount.
Am I to assume that ALPC uses this data and extrapolates it for focus distances far outside those used in shooting the charts, and finally, how important is it
in terms of the quality of the lens correction, to go this exta step of including different focus distances? I'm profiling a prime lens only.
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I have a related question about distortion/focus distance. (Sorry if I'm hijacking!)
Can the lens profiles include variations by focus distance? For example, I have problems using the Adobe profile for Nikon's 14-24/2.8. In use, the profile overcorrects to a pincushion state. I usually need to back off the correction amount to ~60%, which isn't perfect.
Is it even feasible to create a profile for a superwide at a far focus distance? Seems like the target would be too small in the frame.
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I have a related question about distortion/focus distance. (Sorry if I'm hijacking!)
Can the lens profiles include variations by focus distance? For example, I have problems using the Adobe profile for Nikon's 14-24/2.8. In use, the profile overcorrects to a pincushion state. I usually need to back off the correction amount to ~60%, which isn't perfect.
Is it even feasible to create a profile for a superwide at a far focus distance? Seems like the target would be too small in the frame.
You can use different focus positions. With a wide angle you are going to need a very big chart though. You don't have to use the Adobe supplied shooting charts - you can make your own if you need different sizes/grid sizes.
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You can use different focus positions. With a wide angle you are going to need a very big chart though. You don't have to use the Adobe supplied shooting charts - you can make your own if you need different sizes/grid sizes.
thank you so much!