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21 January 2009 @ 04:50 pm
I'm back in town . . .  

And just dropped off the film so as of yet have nothing to show for it. And even after I pick up the slides and negs, it'll probably take me a while to get them scanned in.

So I reckon I'll dip into the file and pull out one I took a while ago in a brazen and daring attempt to keep you (at least somewhat) amused until I can get some of the new stuff up. If any of the new stuff turns out to be worth posting.

Click the on photo for larger view. Or see all my albums at http://imageevent.com/fredcritter.

 
 
Current Mood: tiredtired
 
 
 
guppiecatguppiecat on January 23rd, 2009 03:48 am (UTC)
Huh, I never realized that you were still shooting film.

When you scan it in, is it a single-pass, or do you scan the red, blue and green channels separately? (I've heard of interesting effects when you do the latter, so I'm curious.)
Fred A Levy Haskell: xclip- earthfredcritter on January 25th, 2009 04:21 am (UTC)

It’s not that odd an assumption for you to have made. After all, so many folks in our community have gone digital now. Me, I’ve been holding off for a number of reasons, only one of which is financial—I think I may have a rap about it somewhere in the dim past here on LJ. I am thinking that when I do pick up a digital body I’ll probably use it for color work but will continue to use the film body for B&W; I’m one of those odd ducks who likes film grain.

Hm, I don’t believe I’ve heard of running separate passes for each color. Interesting. What sorts of effects do people report?

I’m using VueScan software to drive a Nikon SuperCoolscan 5000 scanner. I still feel rather like I’m in the “trying to figure out exactly what I’m doing” stage, even though I’ve been scanning off and on for quite some time now. Part of what wrought havoc on my learning curve was I was using a previous model which had some serious problems with the strip-film feeder—it got to the point that I was afraid to use it for negatives.

As I write this, I’m scanning in B&W negs and am using pretty straightforward settings. On the other hand, after reading the VueScan documentation and putzing around and so on I’ve decided to use the “multi-exposure” setting when scanning slides. (I haven’t come to a decision about whether I’ll want to do that when scanning color negatives.) The VueScan manual describes its multi-exposure feature this way:

This option provides a way to get additional detail from the darker parts of the scanned image. It is available on scanners that are able to increase the CCD exposure time.

A first pass is performed as usual with the normal RGB exposure. This will be an appropriate exposure for the image as a whole. Then a second pass is performed with a longer exposure, which can reveal additional detail in dark areas not captured in the first pass. VueScan then merges the results of the two by choosing from either the first or second exposure pass.

I reckon that over time I’ll get a better handle on exactly what I’m doing and will become more proficient. Even when I get a digital back, I’ll still have many, many years’ worth of slides and negatives to scan…

guppiecatguppiecat on January 25th, 2009 04:42 am (UTC)
The main effect can be seen here: http://www.kenrockwell.com/tech/bayer.htm

Scroll down to the example photo and roll your mouse over it. I'm thinking that there's more along that vein that could be done with split scanning (or having the CCD in a digital camera work differently and at a higher bit rate).
Fred A Levy Haskellfredcritter on February 1st, 2009 12:52 am (UTC)
Hmmm. Interesting, but… um. I read the page you linked to but it made my brain hurt. The rolled-over image is what it looked like to the naked eye? The camera is in the habit of producing an image that far out of line with what we see? Or was it about sharpness and the real obvious color difference is just incidental? <scratches head> Did you understand what he is talking about? Would you be so kind as to explain it to me? Thanks!
guppiecatguppiecat on February 5th, 2009 02:55 am (UTC)
His point is that one thinks of digital sensors like grids, where each location on the grid measures an amount of red, green and blue light. This isn't true. What really happens is that you have alternating detection of these colours.

Thus, you wind up with grids that look like this:

RGBRGBRGB
GBRGBRGBR
BRGBRGBRG
RGBRGBRGB
GBRGBRGBR

So, digitial cameras don't give you the resolution you think you get.

When you look at film scanning, the film is scanned three times. Once for red, once for green and once for blue. What this means is that you wind up with MUCH sharper results if you scan film vs just using a digital camera. This is because you get three times the information in the resulting image.

The colour differences of the example are, I think, to be ignored. What's interesting is the definition of the fine bits of the flower (stamens, I think). His example wasn't great, as he used different lenses and different light.

My main point was that if you scan in film, you wind up with three (or more) images which are then interleaved in the software. This gives you the ability to do fine tuning at an earlier stage in the process than is possible with digital. I was wondering if that was a real or just a theoretical advantage.