How Can I "Lock" Scanner Exposure in Vuescan or NikonScan

[joe_oliva]

I am trying to stitch together a panorama I took of four frames.

Please see the attached jpeg for a single frame view taken with a wide

angle lens.

 

The panorama sections were taken with a Pentax 6x7, fully manual

exposure, with no change in settings between frames. When I scan the

indivdual frames with my Nikon LS 9000, the auto exposure makes

adjustments to each individual frame such that there are differences

in both the color and contrast between frames. Unchecking auto

exposure in the NikonScan preferences doesn't seem to help, and the

Nikon guide is slightly better than useless.

 

I purchased Vuescan this week, which is generating better results, but

still differences between frames. The problem here is with the

continuous tone of the sky, as well as the subtle white of the jet,

even small diffences in color and contrast stand out like a sore

thumb. It is not important that the scanned frames turn out well

exposed, and color corrected, that is what I will address in

post-scanning processing, but it seems to me that I should be able to

set the exposure for one frame, lock it, and use it for subsequent frames.

 

Thanks much for your (informed) input.

 

All the Best,

 

www.Jetpix.com<div></div>

[steven_clark]

You can do it in Vuescan. Just read the manual under the "advanced workflow" section.

[awindsor]

You can do this in VueScan by showing all of the options in Input. Go the full hog and lock both film base colour and (most important) image colours. Make sure you do not clip to % white point and black point since this will alter colour balance too. <P>

 

If you get close then using <A HREF="http://enblend.sourceforge.net/">Enblend</A> will get you the rest of the way. This will even account for light fall off which is likely to be a problem even with correctly scanned negatives.

<P>

 

Hope thats helps !

[awindsor]

Selecting HTML in "The above text is: " dialog yields: <P>

 

You can do this in VueScan by showing all of the options in Input. Go the full hog and lock both film base colour and (most important) image colours. Make sure you do not clip to % white point and black point since this will alter colour balance too. <P>

 

If you get close then using <A HREF="http://enblend.sourceforge.net/">Enblend</A> will get you the rest of the way. This will even account for light fall off which is likely to be a problem even with correctly scanned negatives. <P>

 

Hope thats helps !

[john_amiet2]

Joe, apart from the advice offered above, I have 'solved' a similar problem when scanning an XPan neg in two sections and then recombining for printing. I could not get colours to match in the two halves using VueScan, which IS an excellent program. I solved it by scanning as RAW, combining in PS and then invering. Then adjust levels etc of each layer until the visually match. Then flatten. It may be a bit 'nuts and bolts' like but I have an exhibition print of it hanging that is very popular with the punters.

[joe_oliva]

You all have been most helpful. A VERY large print is going on display in Washington D.C. in March, after which it may end up at the Unit that operates AF-1.

[andrea_d.]

If you want to avoid Nikon Scan do autoexposure for every frame automatically be sure to uncheck the corrisponding option in "Preferences-single scan" and "Preferences-preview settings" (also "preferences-batch scan" if you do this). Then choose the frame better exposed and let the scanner manually expose on it (clicking on the button half white-half black). Then scan it and the other frames without changing anything. It works.