Soft scans or soft images?

[JPlomley]

The conundrum is that I have to examine my transparencies with my scanner.

I would invest in the Schneider 3x loupe designed for 6x7cm. It will allow you to critically evaluate your chromes and weed out soft images.

Try to avoid f/45 and f/64. In my experience I try not to shoot past f/32.3 (3mm focus spread). It's also important to characterize your lenses to see what you can get away with. A simple high frequency subject imaged at f/22, f/32, f/45, and f/64 will quickly reveal a deterioration in image quality. For example, I know my 135, 210, and 300 APO Sironar-S lenses can handle f/45 if absolutely necessary, and still provide excellent image quality. However, f/45 is unacceptable on the 75 and 90 Grandagon-N's, so I will optimize my movements/composition to avoid the focus spreads requiring this aperture on the wide angles.

Have to agree with Ted on the sampling resolution having gone through this myself. All you are doing is accentuating film grain, thereby reducing your signal to noise ratio. The advantage of shooting 4x5 is that we can scan at lower resolution compared to the smaller formats for equivalent print size, thereby eliminating noise. If you are making exceptionally large images and therefore need to scan at maximum resolution for the pixel count, then you better plan on running a noise reduction program like Neat Image or Noise Ninja. But on a file that size, you can take a long break for lunch.

[Greg Lockrey]

Based on what Rob and Ted are both saying, then the optimal resolution for film scanning with the 750V would be at the 2400 ppi setting since the scanner's max is really 2400 vs stated 4800 ppi. (How does one determine this?) Down sizing the file from there would work too I would imagine. Another point about grain size and scanning was made about too high of a ppi would inhance the grain. I always thought that if the pixal size was larger than the grain, then the grain seemed to have increased to the pixal dimension. That was why scanning at higher resolutions was better to minimize grain. I'm confused now.

[Ted Harris]

Greg, I test scanners using an AIG test target, these are the imaging industry standards.

[Greg Lockrey]

Greg, I test scanners using an AIG test target, these are the imaging industry standards.

I was just curious, thanks. We don't always get access to this high tech stuff here in the "Tundra". Are there links to results? Or does the 96 ppi of a monitor screw up the results too much?

[Brian Ellis]

Agree with Ted. Scanning at a higher ppi than the scanner is capable of resolving does nothing but increase the file size without any gain in information.

As to the original question, there are so many possible variables here it's hard to tell exactly why your cropped image is soft. Clearly you should be scanning at about 2200 ppi rather than 1200. But apart from that, it sounds like you might just be more or less automatically stopping down to f45 and f64 to gain depth of field. If that's the case you might read the article in the articles section of this forum dealing with focusing the view camera. With a little study of that article you'll learn how to find the optimum aperture for any given scene, which often will be less than f45 or f64 unless you're in the habit of making photographs with extreme near-far relationships. Among other benefits, that will allow you to increase shutter speeds to something faster than the several seconds you mention. Using a faster shutter speed obviously will reduce the effects of slight camera movements, subject movement, etc.

[Gene McCluney]

Something that hasn't been mentioned specifically in this thread, but it seems that ALL scanners require a bit of "sharpening" of the scan in Photoshop, after you size the image to your final print size.

[Ted Harris]

I think we all may have been assuming that the OP knew about sharpening, but maybe not. In fact , for consumer scanners it is generally more than a bit of sharpening that is required. As a rule of thumb you can start with a radius that is 5% of your resolution and 220% and then back off until your image looks the way you what it too; that is, sharp enough but without obvious digital artifacts. Also remember that you must sharpen at the printing size or things may get interesting.

[walter23]

"3mm focus spread"

Can you explain this terminology? I've never heard of this and I can't even guess.

Sharpening - yeah, I know about that. Of course the thing about sharpening as we all know is that you don't gain any real resolution, just increase the perception of edges. I tend to err on the side of undersharpening to avoid haloing.

[65Galaxie]

You just need to add some sharpening in photoshop. Flatbed scanners show very blurry without any sharpening. Here's a slight redo on your crop. The extra grain won't be noticable on enlargening to at least 16x20.

[Brian Vuillemenot]

I wouldn't stop down past f/32 routinely, except if you need the extra depth of field, by all means stop down rather than get out of focus areas. Be sure to use appropriate unsharp masking. The Epson flatbeds are really only good for 3-4X enlargements, so if you are making bigger ones, you may want to invest in drum scans. It's not your lenses- I have a 210 Caltar-IIN, and it's among my sharpest lenses- definately as good as my 150 Apo Sironar-S, and probably sharper than my 110 SS-XL.