[Digging back in time here...: I know the following isn't really a direct
answer to the question, but I just thought I'd bring this technique to your
as the basis for the technique, me and Joel Benford (lurker on this list)
set about merging 3 frames into 1 image. We did this on a number of images.
He'd used a tripod to make night photographs and carefully bracketed, with
the intention of merging later.
His HP Photosmart S20+ scanner is no good for this task, as the motorised
film feed during scanning causes misregistration of the images. So we
ended-up using my Primefilm 1800 scanner (you may think this scanner is crap
but it has pixel perfect registration, something I still find quite
astonishing!). I no longer have the Primefilm. Tests with the LS40 show it
does the job equally well.
Instead of using Peter's four control points for the +2EV image, I used two:
And instead of using his control points for the -2EV image, I used:
The results were very worthwhile. See some samples at:
The hardest part is correcting for any rotational error you introduce by
scanning. You should experiment with the curves, to suit your taste and, I
suppose, the nature of the film used.
Of course, Vuescan does this automatically for a single frame, if your
scanner supports Vuescans "long exposure pass" option.
> -----Original Message-----
> From: firstname.lastname@example.org
> [mailto:email@example.com]On Behalf Of Rob Geraghty
> Sent: 26 September 2001 00:10
> To: firstname.lastname@example.org
> Subject: filmscanners: RE: filmscanners: Merging multiple scans in
> Photoshop to deal with very high-contrast scenes
> Anthony asked:
> >Has anyone here done any significant work with merging multiple scans to
> >overcome limitations of film in high-contrast scenes?
> I've tried it with two layers. It tends to show up the limitations of the
> scanner very quickly. If you have a scanner with a good range, you may
> not have the same issues I did with the LS30. The balance
> between the layers
> had to be very carefully made, or dark noise and banding ruins the image.
> Rob Geraghty email@example.com