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The Definitive Sony B&W Images Thread

KenLee

Active member
They are. They are linear outputs. The mid tone needs to be stretched to make them look brighter.

Working on it.. :)


I tried applying a Gamma 2.2 layer adjustment in Photoshop: that may be to much, but it's remarkable how much noiseless data is in the shadows.
 
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V

Vivek

Guest
Not the way to go. Yes, there is a lot of useful data.

I tried applying a Gamma 2.2 layer adjustment in Photoshop: that may be to much, but it's remarkable how much noiseless data is in the shadows.
 

scho

Well-known member
Vivek,

Your crops are private so I can't see the full size images. I can also see the pixel grid in background of my Darktable images and being only 24 mp they are likely more evident than with your 42 mp images. I will print a few images and if the pattern is not evident in the prints (very likely) I'm just not going to worry about it anymore.

Carl

Learnt one way to stretch the image output.


Untitled by Vivek Iyer, on Flickr

There are pixel squares. Crops from the background window (67% and 300%; different areas):

300%

Untitled by Vivek Iyer, on Flickr


67%

Untitled by Vivek Iyer, on Flickr
 
V

Vivek

Guest
Carl, I will send you (large version)of some other image taken at the same place.

With an ipad, you can enlarge the crops i posted to see the squares. They are much smaller than yours.
 

LargeSense

New member
Hi,

I assume the pattern is a result of an in factory flat field calibration with the CFA. When you remove the CFA, the calibration will be off. This would most likely be applied to all images in the camera even RAW. RAW is usually not the exact image off the sensor.

There some free astro software out there that might help doing a custom flat field. It would be a lot of work for every image but could be applied to some special images.

Bill

Learnt one way to stretch the image output.


Untitled by Vivek Iyer, on Flickr

There are pixel squares. Crops from the background window (67% and 300%; different areas):

300%

Untitled by Vivek Iyer, on Flickr


67%

Untitled by Vivek Iyer, on Flickr
 
V

Vivek

Guest
Thank you, Bill for the pointer! Dark Table, indeed has a flat field option. I will explore that.

Carl, Here is one that is a larger file (3000x2000).

Untitled by Vivek Iyer, on Flickr
 

scho

Well-known member
Thank you, Bill for the pointer! Dark Table, indeed has a flat field option. I will explore that.

Carl, Here is one that is a larger file (3000x2000).

Untitled by Vivek Iyer, on Flickr
Thanks Vivek. I looked at your crops on the iPad and scaled them up so I could make out the pattern. I could not see the pattern on this 3000x2000 image, but probably could by scaling up on the iPad. I also saw that flat field option in Darktable but not sure how to use it yet. I use the LR flat field app for correcting lens casts but not for very fine grid patterns, but I guess it should work.
 
V

Vivek

Guest
Carl, At 600% there is a defined pattern! :bugeyes: For normal use, most of the time, it is going to be OK. :)

Let us compare notes on the flat field use. Thanks.
 

KenLee

Active member
Hi,

I assume the pattern is a result of an in factory flat field calibration with the CFA. When you remove the CFA, the calibration will be off. This would most likely be applied to all images in the camera even RAW. RAW is usually not the exact image off the sensor.

There some free astro software out there that might help doing a custom flat field. It would be a lot of work for every image but could be applied to some special images.

Bill
Hey Bill - Nice to see you :D
 

scho

Well-known member
RPP (Raw Photo Processor) to the rescue! No more pixel dot pattern.

 
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