iSRD Dust Removal feature

[john10001]

I have tried using this feature in Silverfast and it seems to me to be a software based feature not hardware is this correct?

Also when I use it to remove scratches and dust the settings that I have to use in order to do this also wipe out peoples eyes, teeth and other areas that it also thinks are defects when they are not. Lowering different settings doesn't help much because then it also still leaves in the true defects the dust and scratches and doesn't reduce them by much.

For example on one negative setting detection at 65, defect size at 7 and intensity at 100 will get rid of the dust and scratches but it will also remove other detail that are not defects like eyes, and finer detail in the image. Reducing the settings to detection 55, defect size 3, intensity 100, will prevent this but leave large portions of dust and scratches still visible. These figures also differ greatly from one negative to the next so as to make it pretty much worthless as a feature as it would take up so much of your time doing these settings for each individual frame to make it not worthwhile cost/benefit/time wise.

Just wondering if anyone has had good results using the iSRD feature and found settings that you can apply to all your scans to get a decent level of dust and scratch removal without sacrificing detail and noising and softening out your results into a watercolour?

I feel I may as well just use the CanoScan software to do this because it is faster and I can also scan at 48 bit colour to get a positive and not have to revert the colours in software to obtain this. I can then just use dedicated software to remove any noticeable defects by hand without affecting things that are not defects.

John

[LSI_Morales]

Hi John

I have tried using this feature in Silverfast and it seems to me to be a software based feature not hardware is this correct?

Incorrect iSRD stands for infrared smart removal of defects. The "infrared" part means it needs an infrared channel which is a hardware feature (not included in all scanners).

SRD is a software based feature equivalent to iSRD but without the infrared channel. Detection of scratches and dust is made by a software algorithm.

There are certain types of film emulsions which disperse the infrared light and send the image information as defects in the infrared channel. Kodachrome and silver halide black and white are two classic emulsions affected by this handicap.

Also when I use it to remove scratches and dust the settings that I have to use in order to do this also wipe out peoples eyes, teeth and other areas that it also thinks are defects when they are not. Lowering different settings doesn't help much because then it also still leaves in the true defects the dust and scratches and doesn't reduce them by much.

If you are using iSRD and have this kind of effect, you might use masks and select the areas where such defects should be corrected leaving the important details untouched.

Cheers

[john10001]

Thanks for clarifying. If this is the case I don't think iSRD is working then and it seems to be only the SRD part that is being utilised. I would say it definitely seems to be only software only that is actioning in my Silverfast so I have probably not done something correctly? In the Canon software the dust and scratch removal feature does seem to work on the infrared channel but I only get good results when it is set on high setting and everything else is disabled. I can tell this is definitely the hardware because I am not getting things that are not defects taken out too.

[LSI_Morales]

Hi John

I would say it definitely seems to be only software only that is actioning in my Silverfast so I have probably not done something correctly?

Since I am not sitting next to you is hard to say if you are only using SRD or if there is a problem with the program or the scanner.

Are you working with SilverFast 6.6 or SilverFast 8?
Is it SE, SE Plus, Ai or Ai Studio? Which operating system?

Cheers