importance of Dmax for those who scan slides?

[cherieamour]

Hello people,

The Dmax of scanners are often taken into consideration, because it helps in bringing out details (I think), but has anyone found it really true in practice?

For example, the Epson v500 (dmax: 3.4) vs Epson v700 (dmax: 4.0?)

If one scans a lot of slides, especially those with high Dmax of around 3.8 such as Velvia or Ektachrome, will details really be brought out on the Epson v700, and lost on the Epson v500?

Also, is high Dmax needed for slides that have been "exposed well" or in good conditions with no large density range?

Or, can slides be scanned on a scanner with Dmax of 3.4 and perhaps using multi-pass on Vuescan or photoshop to dig out details?

Hope those who scan slides with scanners of known Dmax can share their opinions (:

Thanks!

[kanni]

Scanner with Dmax can help to bring out details in dark area.

Maybe I separate the issues first.

1) Dmax-Dmin = Dynamic Range.
If your slides have very bright and very dark regions, multi-exposure (scan at different exposure) will help. I didn't try Vuescan before. But I tried SilverFast. They have an image sample in their site.
http://www.silverfast.com/highlights...posure/en.html

I dunno Vuescan definition for multi-pass. If it is multi-sampling (scan the same image twice or more using same exposure), it can only help to reduce random noise caused by the hardware.

2) Dmax of 3.4 vs 4.0
This value shows the hardware capability to extract dark information. If the hardware cannot support, with the use of software, it will still not work out well.

Practically, I am not a very good photo-taker (too noob to state myself as photgrapher :P). So, the slides that I took dun really make full use of the film capability.
I think in my normal usage, 3.4 is sufficient for me.