leaf gain adjuster

[rueyloon]

hello

hi, anyone using the leaf gain adjuster ?
I find that if I do ilumination correction as well, it adds alot of noise
to the image. Are you guy getting the same result ?

cheers

[rainer_v]

hello

hi, anyone using the leaf gain adjuster ?
I find that if I do ilumination correction as well, it adds alot of noise
to the image. Are you guy getting the same result ?

cheers
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there are two ways how noise can come in the image: pushing up the level of the vignetted corners of the image will increase the noise level, simply because they are underexposed as the result of the lens caused vignetting.
so applying a  center filter will avoid his better than software levelling.

the seond reason may be the following:
i always wondered about how the gain adjuster can adjust the vignetting without adding at the same time the noise .... the way how to avoid this should be to soften or to denoise the white reference file, but  the gain adjuster has to remove also at the same stage of processing the centerfold issue, which is visible in form of a defined line, so softening is not possible, otherwse the cf line would appear again.
its logic that the noise of the white refernce shot is added to the image. noise level should be more or less the double than without the adjuster.as longer the white shot is, as more noise should be added.
brumbaer tools has had the same problem till it was introduced its "denoise" function one year ago. with the B-tools this is possible because the tools do not have to remove the cf at the same stage, the cf is removed by a sw code meanwhile transferring the images.
 supose phaseone goes here a similar way with its LCC method. they dont have to remove any centerfold, so they can soften their LCC shot, which does not introduce new noise to the image.

[rueyloon]

Hi, this is good, I'm getting more ideas. Since noise is a function of ilumination (I see more noise in the shadow area), if I shoot the reference file much brighter, say almost blowing the highlights, I'll end up adding less noise when doing the correction, sound theory ? I'll test it out in my next shoot.

there are two ways how noise can come in the image: pushing up the level of the vignetted corners of the image will increase the noise level, simply because they are underexposed as the result of the lens caused vignetting.
so an center filter will avoid his better than software levelling.

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[rainer_v]

if I shoot the reference file much brighter, say almost blowing the highlights, I'll end up adding less noise when doing the correction, sound theory ? I'll test it out in my next shoot.
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 so it is ...

[yaya]

Ruey the user guide for the CGA instructs you how to expose the Gain file, usually by adding 2 stops in shutter speed. (the diffuser filter cuts approx. 2 stops).

This will ensure that there is minimum or no noise added to the corrected file. The centrefold is being corrected just like any colour cast (it IS an acute case of colour cast) which is why we don't need to soften the Gain file.

Yair

[adammork]

hello

hi, anyone using the leaf gain adjuster ?
I find that if I do ilumination correction as well, it adds alot of noise
to the image. Are you guy getting the same result ?

cheers
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If you expose, so the histogram is as close as possible to +2, without going over, you will se no noise in the adjusted image.

For interior, adding around 2 stops is normally what it takes, but outside on a sunny day I often need to add 4 stops.

For not ending up with too long exposures inside, I use a small handheld flash all the time - This do the trick!


/Adam

[rainer_v]

If you expose, so the histogram is as close as possible to +2, without going over, you will se no noise in the adjusted image.

For interior, adding around 2 stops is normally what it takes, but outside on a sunny day I often need to add 4 stops.

For not ending up with too long exposures inside, I use a small handheld flash all the time - This do the trick!
/Adam
[a href=\"index.php?act=findpost&pid=152085\"][{POST_SNAPBACK}][/a]

great idea.