Re: filmscanners: Film grain vs 2700 DPI scan resolution
"Frank Nichols" <[EMAIL PROTECTED]> wrote: > 1. With 200 film, is the grain "large" enough for the 2700 DPI to record it? > If so could some one describe it (or email me a couple scan clips showing > examples?) Colour neg films have a random mixture of different sized dye clouds. The only C41 film I've scanned which showed no appreciable apparent grain in mid-tones and highlights was T400CN B&W film exposed at EI250. All other C41 films *seem* to show "grain". I don't think anyone one the list has the exact figures to show the comparison between dye cloud size and the area of a pixel at 2700dpi but from what I've read here, some are approaching the same size. Errors occur when the CCD elements see the boundaries between different coloured dye clouds and these errors create a random pattern resulting from the random pattern of dye clouds in the film. So what you see *isn't* actually the grain, but an interference pattern based on the grain. > 2. Would you expect 1 stop down to be enough to see serious increase in > grain in 200 film in these conditions? Yes. Referring back to the scans of T400 I see a serious increase in the apparent grain in shadow areas of the same frame. So I'd expect any change in exposure with a C41 film to demonstrate a change in apparent grain. Define "serious" however. :) > This weekend I am going to repeat the tests with a couple rolls of FUGI > Provia 100F to see if the "noise" I am seeing FUGI 200 goes away. With low contrast images in Provia 100F and a 2700 dpi scanner you shouldn't see any significant artifacts caused by grain. Higher contrast images will probably start to generate problems with scanner noise in the shadows but this is *not* anything to do with film grain aliasing. For a more meaningful comparison of grain in C41 it probably makes more sense to compare a 10x8 enlargement with a 2700dpi scan than to look at a 6"x4" print. Rob
Re: filmscanners: Film grain vs 2700 DPI scan resolution
At 07:26 PM 6/30/01 -0600, Frank Nichols wrote: >1. With 200 film, is the grain "large" enough for the 2700 DPI to record it? >If so could some one describe it (or email me a couple scan clips showing >examples?) To answer your question. Yes. Frank, the biggest single improvement in my photo "technique" these last couple of years was giving up on generic ISO 200 negative films. I may have stumbled on to that discovery, but the difference in the scans was huge. And I made this discovery (and saw the vast improvement in the scans) while using a 1950 dpi film scanner (Microtek 35t+). Try a roll of Fuji Reala or Kodak Royal Gold and see if you don't agree. Both are ISO 100. As I write this, I'm scanning one of my favorite (old) images to see if the Nikon can improve on earlier scans. What a pity -- the image is on Kodak Gold 400, and the grain is just awful. rafe b.
Re: filmscanners: Film grain vs 2700 DPI scan resolution
I suggest you try this grain reduction algorithm... similar to PS Smart Blur but better at isolating smooth backgrounds from a face etc.., experiment with small images first to find the right settings. http://www.rphotoz.com/astrophoto/bgsmoothwindl.html rafeb <[EMAIL PROTECTED]> wrote: >As I write this, I'm scanning one of my favorite (old) >images to see if the Nikon can improve on earlier scans. >What a pity -- the image is on Kodak Gold 400, and the >grain is just awful. > > >rafe b. Herm Astropics http://home.att.net/~hermperez
Re: filmscanners: Film grain vs 2700 DPI scan resolution
On Sat, 30 Jun 2001 23:31:24 -0400 rafeb ([EMAIL PROTECTED]) wrote: > >1. With 200 film, is the grain "large" enough for the 2700 DPI to > record it? > >If so could some one describe it (or email me a couple scan clips > showing > >examples?) > > > To answer your question. Yes. I suggest you stick some of your old ISO200 pics through that LS8000, and see if they now exhibit the 'grain' they did at 2700ppi - I bet they don't:) One interesting anomaly of the SS4000 is that whilst it shows very little grain from Fuji Superia 400, and not much even with 800, it shows some of the gritty pseudo-grain with Fuji 200 which I ascribe to aliasing. It certainly isn't present in lab prints direct from the negs. I believe the ISO200 grain just happens to be of a range of sizes which cause an aliased result with this CCD pitch, where 400 and 800 are larger and do not - so you see 'true' grain from these materials. To see true grain from ISO50-100 colour neg or tranny, I think you'll have to be on the far side of 8000ppi. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner info & comparisons
Re: filmscanners: Film grain vs 2700 DPI scan resolution
On Sat, 30 Jun 2001 19:26:33 -0600 Frank Nichols ([EMAIL PROTECTED]) wrote: > 1. With 200 film, is the grain "large" enough for the 2700 DPI to > record it? > If so could some one describe it (or email me a couple scan clips > showing > examples?) No, IME you are unlikely to see genuine grain off ISO200 Fuji using 2700ppi. You are likely to get some aliasing which looks like grain. A way to check this would be to have a reasonably large C41 print made (say 12x8"). I'll bet. > 2. Would you expect 1 stop down to be enough to see serious increase in > grain in 200 film in these conditions? Yes, you'll likely see quite a large increase in apparent grain in darker tones (eg shadow areas) especially. > > This weekend I am going to repeat the tests with a couple rolls of FUGI > Provia 100F to see if the "noise" I am seeing FUGI 200 goes away. It will. Also try a slower colour neg film, eg Reala. Regards Tony Sleep http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner info & comparisons
Re: filmscanners: Film grain vs 2700 DPI scan resolution
At 12:07 AM 7/2/01 +0100, Tony Sleep wrote: >On Sat, 30 Jun 2001 19:26:33 -0600 Frank Nichols ([EMAIL PROTECTED]) >wrote: > >> 1. With 200 film, is the grain "large" enough for the 2700 DPI to >> record it? >> If so could some one describe it (or email me a couple scan clips >> showing >> examples?) > >No, IME you are unlikely to see genuine grain off ISO200 Fuji using >2700ppi. You are likely to get some aliasing which looks like grain. A way >to check this would be to have a reasonably large C41 print made (say >12x8"). I'll bet. Well, I don't know if it's grain or an alias of grain, and not sure I'd recognize the difference. To me, it just looks like grain. Not just on the print, but on screen as well. To be honest, I never did color darkroom work on C-prints, just a bit of Cibachrome printing. But I sure have seen my share of 35 mm, Tri-X, pushed to obscene speeds and printed at 8x10" and 11x14", on an Omega B22 condenser enlarger. Whatever this stuff is that I'm seeing, it clearly correlates to film ISO rating and quality... just like grain. So I guess to my feeble mind, simple "grain" is an adequate model for what I'm seeing. Not having the wherewithal to get 8000 dpi scans of my images, this simple (though flawed) model will suffice until new observations warrant its replacement. rafe b.
Re: filmscanners: Film grain vs 2700 DPI scan resolution
Which brings up some additional questions-- I'm a real newbie to this area, though a physicist by trade. I've suddenly gotten interested in photography again, after a long lapse. I bought me an Acer 2740S, which seems to be a reasonable low-cost entry machine, and began exploring unknown (to me) territories. I thought I'd stick to Fuji negative film and see what happens with various speeds, from 800 down to 100 (is there anything slower readily available?), and various VueScan settings. Any suggestions as to what I might expect, what to try, and what to look for? . . . . . . On Mon, 2 Jul 2001 00:07 +0100 (BST), you wrote: >On Sat, 30 Jun 2001 23:31:24 -0400 rafeb ([EMAIL PROTECTED]) wrote: > >> >1. With 200 film, is the grain "large" enough for the 2700 DPI to >> record it? >> >If so could some one describe it (or email me a couple scan clips >> showing >> >examples?) >> >> >> To answer your question. Yes. > >I suggest you stick some of your old ISO200 pics through that LS8000, and >see if they now exhibit the 'grain' they did at 2700ppi - I bet they >don't:) > >One interesting anomaly of the SS4000 is that whilst it shows very little >grain from Fuji Superia 400, and not much even with 800, it shows some of >the gritty pseudo-grain with Fuji 200 which I ascribe to aliasing. It >certainly isn't present in lab prints direct from the negs. I believe the >ISO200 grain just happens to be of a range of sizes which cause an aliased >result with this CCD pitch, where 400 and 800 are larger and do not - so >you see 'true' grain from these materials. > >To see true grain from ISO50-100 colour neg or tranny, I think you'll have >to be on the far side of 8000ppi. > >Regards > >Tony Sleep >http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner >info & comparisons . . . . . . Socrates was a lawyer. He could argue, with equal conviction, on either side of any question.
RE: Re: filmscanners: Film grain vs 2700 DPI scan resolution
> Frank, the biggest single improvement in my photo > "technique" these last couple of years was giving > up on generic ISO 200 negative films. I took a different approach...I use MF. I can shoot Tri-X till the cows come home, developed D-76 1:1, and they look very good IMO. I know that's B&W, but I'm sure that the same would apply to color. I do really like shooting 35mm, but anything I really want to scan, and expect better than 8x10, I've resigned my self to MF. Mail2Web - Check your email from the web at http://www.mail2web.com/ .
