Railfan Technology > What scan resolution

I've ammassed enough slides that I want to start sending groups out to get them scanned.  I plan to sell off the slides at that point (so I can buy more slides:)  So that brought me to an interesting question: Places like Digmypics reccommend scanning at 2500dpi as a good size.   I'd like to use the scans to print out larger format picture books and to view on my 4K TV.  So, given that display technology keeps evolving and being able to display higher and higher resolution, should I get 4000dpi scans to future proof?   The only problem with getting 4000dpi scans that Ive heard about is that they can supposedly look too shrap or "edge enhanced" when shrunken down. 
So given that I'm getting rid of the original slides, should I get them scanned at the highest DPI possible? Thoughts? 

It depends on the actual scanner the firm is using. Overly sharp high resolution scans are usually the product of scanners that don't have high enough native optical resolution so the image is interpolated up and sharpened. It also depends on the originals and how much grain there is. Above 5,000ppi and the scanner can start to "out resolve" the original.

You are right to want to scan the images at the highest possible resolution. Especially since you plan to sell the originals off later. I would find a vendor and send them a dozen or so sample slides and have them scanned at the highest resolution they offer for the machines they are using, then play with the scans to make sure they meet your needs. That's really the only way you are going to be able to determine if a given vendor is able to provide you with the kind of scans you want.

Personally, I have used digmypics.com for a couple projects. They use Nikon Super CoolScan 9000s and the scans are quite good, especially if your originals are sharp and well exposed. I wouldn't hesitate to recommend them if their high resolution scan service is within your budget.

I scan everything at 3200.  Good scan without taking up massive amounts of space.  You can get a good print out of them.  

Trainjunkies' comments make sense to me.  I scan at 4000 dpi with my Nikon Super Coolscan 5000, but when I tried that with my Epson V600 I had to back off to get good results even though Epson claims 6400 x 9600 dpi resolution. For much of what I do high resolution is not important, like posting on the internet.  But occasionally I get the opportunity to see one of my 35 slides blown up really large, and it is amazing the detail that can be had at 4000 dpi.  But with a 35mm slide anything higher than 4000 dpi is likely to be limited by the grain of the film.  Even at 4000 dpi the film grain is often/usually the limiting factor.

I might add that a lot depends on the film you were using.  My old Kodachrome II slides usually scan really well at 4000 dpi, better than Kodachrome 64 and probably even Kodachrome 25.  But I made the horrible mistake of using a lot of Kodachrome 200 for added depth of field with a long lens.  It looked reasonably ok when projected on a lenticular screen, but the scans bring out all the color and grain issues of what must have been world's worst slide film, even my old Anscochrome and Ektachrome does better when scanned and run through Photoshop.

JBWX



Edited 1 time(s). Last edit at 01/23/19 17:25 by jbwest.

Thanks for all the input.  I'll do a sample run on 12 slides or so and maybe have them done at both resolutions.  Then I can play with them and see what works and what doesn't.