Low-res scan or downsample?

abdoujaparov

abdoujaparov

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Keith
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Most of what I do with my images involves putting them up on the web at roughly 1000 pixels longest edge. Given this, which do you think gives the best result - scanning at roughly that resolution, or scanning at the maximum my scanner can realistically do, and resizing at the end of my editing process? I.e., is the downsampling process more intelligent than just not scanning the pixels in the first place? Obviously I'd rather scan at the lower res simply because it takes less time.

Or is this angels-on-the-head-of-a-pin stuff?

(Obviously if I want to print big, I'll scan at the high res - this is just about web versions)

Edit: argh, wrong sub-forum. I'll report it. Sorry.
 
Moved for you
 
I'd be interested in hearing what the experts say about his. I also shoot on film to share digitally. I usually scan (V500) at a fairly high dpi (2400), save my images with minimal compression in .jpeg. I then select images for sharing digitally, and resize using Gimp (and a little optimisation such as dust healing) to a maximum length of 2800 pixels, with a little more compression, before uploading to Flickr.

Would I be better off scanning at a lower resolution? I guess in my mind, I scan fairly high because it gives me plenty of cropping opportunity on a 6 x 6 medium format negative.
 
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Simplest way would just be to scan an image to produce a 1024px file and to scan at a higher resolution and downscale to 1024px then compare them side by side.
 
I'd rather scan large once and resize than scan small and have to rescan later (when I decide to do something else with the image).
 
I always scan at a decent resolution (eg 2400dpi on 135 or 1200 on 120) and save as a DNG raw file - that way I can always "re-scan" from the DNG without having to dig out my negatives again.
 
I tend to make a judgement based on perceived quality of the image. If I'm just scanning it "for the record" I may go as low as 900 dpi. If so-so then 1200. If OK then 1800-2400. If I think I might want to print big then 3600. So obviously the images shared online are downsampled, in my case in Aperture. No real lgic in this, but it feels right to me.

(Note, straightening and cropping all lose pixels, so argue for scanning a decent image at a higher res than one really needs...)
 
Generally, I've found a high quality down-sampled image almost always looks more pleasing than a low-res original. Some of this depends on software and algorithm used to down-sample. For instance Photoshop has specific methods for resizing images depending on whether it's increasing or decreasing the pixel count.

The other big factor to consider is time. Time to create the image you need right now (low-res scan is preferred), and time to create the image long-term (high res scan is preferred as you're not duplicating effort, handling the film twice, loading it, messing with software etc.)

Personally, I would scan once at the highest resolution, archive it in Lightroom or similar and use the master to create any other sizes you need.
 
robhooley167 said:
Simplest way would just be to scan an image to produce a 1024px file and to scan at a higher resolution and downscale to 1024px then compare them side by side.
Click to expand...
Yeah, I'll do that. Was just hoping to have a nice ready-made answer from the hive-mind :D
FujiLove said:
Personally, I would scan once at the highest resolution, archive it in Lightroom or similar and use the master to create any other sizes you need.
Click to expand...

That's the sensible default, for sure. Disk space is cheap, and it's not like I'm staring at the scanner tapping my fingers while it scans (much).

Thanks all.
 
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