Vuescan acting wonky!

[Bernard_L]

6000+ dpi for scanning 4x5
That is 300dpi for a 80x100 inch print, suitable for peeping at nose-tip distance.

[Steven Ruttenberg]

6000+ dpi for scanning 4x5
That is 300dpi for a 80x100 inch print, suitable for peeping at nose-tip distance.

True, but it gives a much better print/image when you reduce it to say 300dpi for 16x20 or 32x40. Although, I am not sold yet on imaging the grain structure so to speak.

[minh0204]

I do panorama stitching and it always had its pitfalls.

Steven, none of the usual pitfalls of panorama stitching will apply here if you don't touch the scanner during the scan. If you are slightly unsure, do a 10% border overlap and the strips will match exactly.

[Steven Ruttenberg]

Steven, none of the usual pitfalls of panorama stitching will apply here if you don't touch the scanner during the scan. If you are slightly unsure, do a 10% border overlap and the strips will match exactly.

I can give that a try. Always willing to try something once. If it works then that is a plus for the toolbox!

[Bernard_L]

Steven, none of the usual pitfalls of panorama stitching will apply here

Except that the geometry is different and I'm unsure how panorama-stitching-software "X" will behave. What the software expects is a 3_D scene and the camera rotating around the entrance pupil (not the stinkin' nodal point, mind you). What you have is a 2-D object and lateral translation.
Hopefully there will be an option for that situation as well.

[Steven Ruttenberg]

PTgui handles flat images very well, I do that all the time with my tilt/shift lenses for my digital camera. You are correct, rotate about entrance pupil not the "nodal" point which is a misnomer for the entrance pupil. I find mine using a laser pointer and visually align/find the entrance pupil for each lens. For each focal length as well if a zoom lens. Once could do this for a fixed prime on large format assuming one only uses the back standard to focus. So, could amke a freaking huge pano iwth a 4x5 using say a 150 or 210 lens. That would be interesting. Same rules would apply, do not alter your exposure setting at all from first image to last, do not alter focus, nor alter f-stop. I have seen people do all of this to "optimize" each frame. Also, if you have significant vignetting that will have to be taken care of by the stitching program. (PTGui will do this if you get the full blown version). Might also require a center spot filter to (maybe, depends on focual length and f-stop used)

[Jim Andrada]

+1 for PTGUI.

[Bernard_L]

PTgui handles flat images very well

I learned something without even having to do the test. Thank you.

[mrred]

When I set the Media to Slide Film, it makes 2 passes, is this correct ?

You probably have the infrared clean option enabled in the filter tab.

[Ted Baker]

One simple solution from a capture perspective if your wet mounting is, three passes with each colour. And simply combine the three images. This does mean that you will need to do the post image processing yourself, which may or may not be a problem (i.e. raw scanning where you do all the processing yourself including gamma, and color matrix). For example if your using colour perfect, that requires a raw scan anyway, so you have don't have to do the hard bits.

Actually I think there may a magic trick to fool vuescan, and get around the 32bit limit. Will give it a go next scanning session and let you know.