Gamma settings

[garyritson]

I am getting to grips with archive suite but lots of slides are coming out too dark. Lots of the slides are indeed over and under exposed but I wish to clear up the gamma situation first. I only have a couple of questions.
Does the gamma settings within silverfast ai and hdri have to be the same as the gamma settings on my pc?
I know this may seem like a simple question but to someone who is just starting any help would be great.
Also when in the hdri side for gamma settings there is a tick box for hdri output, if I tick this what actually happens?
Thanks

[LSI_Morales]

Hi there

Does the gamma settings within silverfast ai and hdri have to be the same as the gamma settings on my pc?

Yes, it has to be the same (some people use a tolerance of +/- 2)

Also when in the hdri side for gamma settings there is a tick box for hdri output, if I tick this what actually happens?

When scanning in HDR or HDRi modes, SilverFast creates a raw file with a linear gamma value which looks underexposed when opened in programs other than SilverFast HDR. By ticking this option SilverFast will export the raw file with the same gamma used for preview in SilverFast Ai.

Cheers

[garyritson]

Hi there,
Thanks for your reply.
I have not had this hdri output tick box ticked on many previous slides, is there a way to make these slides look brighter or do I have to re scan them all again.

Thanks
Gary

[LSI_Morales]

Hi Gary,

If you open your pictures in SilverFast HDR the gamma correction will be performed automatically. If you use other imaging program than SilverFast HDR then you will have to perform the gamma corrections manually with the adjustment controls for every application.

Cheers

[garyritson]

Hello there, I just clicked image auto adjust button but want to go back to the original image, how do i do an undo?
Gary

[LSI_Morales]

Hi there,

If you are working on a Mac you will find the undo button at the left side of the "Prescan" button. Or the key combination "cmd+Z" to undo the last action

On windows, pressing the shift key will switch the "Options" button to "reset" which can be used to reset to the original prescan. Or the key combination "ctrl + Z" to undo.

You might find useful our user manual where you will find a relatively detailed description of the program at: http://www.silverfast.com/documentation/en.html

Cheers

[garyritson]

Dear Sir/Madam
I now seem to have a good workflow going scanning my negs with the correct IT8 targets. I am now getting to the step of working on the raw files and have optimized a few of them.
When I view them on VLT the previews look good, bright and sharp but when i double click them and open them they look dark!!!!! (they open in 24bit colour)
I have checked that the gamma setting is the same as on my computer and in the options.
What could I be doing wrong? Any help would be great,
Thanks
Gary

[LSI_Morales]

Hi Gary,

could you perhaps post a screenshot of your settings in the options dialogue?

Cheers

[garyritson]

Dear Sir,
Here are the three screen shot images. The first is the screen shot the options, the second is a shot of the options plus the darker photo and the third is a shot of the VLT.
Thanks
Gary

[LSI_Morales]

Hi Gary,

Thanks for your screenshots.

You have set the gamma value to 1 which makes images look darker.

Try using a gamma value between 2 and 2,2 (I marked the spot on your own screenshot)

options 3.jpg (55.72 KiB) Viewed 4057 times

Cheers

[garyritson]

Dear Alejandro,
Than you for your reply. I will give that a go. I am just a bit confused though. I was informed in an earlier post that the gamma settings on my computer screen must be the same as in the options. My computer gamma is set currently to 1. Is this still correct?
Gary

[LSI_Morales]

Dear Gary

I am just a bit confused though. I was informed in an earlier post that the gamma settings on my computer screen must be the same as in the options. My computer gamma is set currently to 1. Is this still correct?

No, the gamma setting should not be the same as your screen, it should be the same value as your operating system gamma, Windows gamma value is 2,2.

Cheers

[garyritson]

Dear Alejandro, Thank you for your reply. Does this mean I must re scan everything that has been previously scanned with the Gamma gradation set to 1 ( which is what my screen properties) was telling me it was set to)?
Gary

[LSI_Morales]

Hi Gary

Does this mean I must re scan everything that has been previously scanned with the Gamma gradation set to 1 ( which is what my screen properties) was telling me it was set to)?

A gamma value of 1 is a linear gamma value. If you scanned your pictures in HDR or HDRi RAW modes, they will have a gamma value of 1 anyway. So they can be left that way.

If your pictures where scanned in 24 bits and saved as jpg then those images will probably have to be re-scanned.

Cheers

[garyritson]

Dear Alejandro, Thank you for all of your replies. I think I now seem to be understanding the Gamma issue. One thing that has been a confusing issue to me is why my computer graphics screen properties has gamma set to 1 yet windows Gamma is at 2.2 or so. Would you perhaps guide me as to why my laptop is set up like this?
PS What should my screen properties gamma be set to? If I change it from 1 to 2.2 then everything is very washed out and light.
Thanks
Gary