Digitizing Negatives

<p>I've gone back to shooting some film, in art because I acquired some of the last Kodachromes and had an analog moment that continues.</p>

<p>For processing (non-Kodachrome, got that covered) I still want digital copies, but am unsure what I want in terms of quality. JPEG vs. TIFF, how many dpi, MP's, MB's, etc.</p>

<p>Suggestions as to how far the bar should be, or what is optimal?</p>

<p>Thanks.</p>

<p>It depends what you want to do. If you want 4x6 prints and images to put on web sites, get a CD made when you have the film processed at any old shop that does this sort of thing. Most use scanners that are fast and pretty sharp, have color calibrations for different films and produce low res files.</p>

<p>If you want large prints, there are many places on the net where you can find info on how many pixels you need (but the short version is - smaller prints that you hold in your hand to look at, 300 PPI; larger prints you see from a couple feet back, 200 PPI; wall size prints seen from two or three steps back, 100-150 PPI) and you either need your own scanner or a good shop that will give you higher resolution.</p>

<p>JPGs are fine unless you want to do a lot of digital editing, in which case TIFFs are helpful.</p>

<p>I run the drum scanner at Richard Photo Lab in Hollywood and do this type of scanning all the time. If I was to Archive my work, I would scan my film at the highest possible without interpolation. For my scanner a 35mm can be scanned at approx 245 Mb without interpolation. (100% @ 8000 dpi) Save as tiff with no LZW compression. Also for really important images. I would also scan at 16 bits per channel. Might be overkill for you but you need to determine what the end product would be and scan for that. Its no good scanning at 20 Mb then deciding you want a 30x40. Just my thoughts<br>

phil@richardphotolab.com</p>

<p>@Phil, why do you recommend not using LZW compression for scanned images? LZW is a lossless compression algorithm, so you don't lose anything. It's not like JPEG compression.</p>

<p>6MP 2000x3000 scans in JPEG should be fine. Even that is overkill for viewing on huge HDTV screens and/or computer monitors, as well as printing up to 16x20's. Actually, for most shots other than very detailed landscapes, it is overkill. For the rare landscape you need more resolution on, simply have that slide scanned seperately at max resolution (pro lab).<br>

I used to subscribe to the "always scan at max resolution" mantra, until I realized that most shots look worse at such high rez. It simply magnifies the graininess, with little extra detail, and creates huge file sizes. I conducted tests, and found that 6MP images are the "sweet spot" for me. I could see no difference in prints up to 12x18 vs scanning at 5400dpi, and the on-screen appearance of the 6MP images was actually smoother and better! Plus, you always have the original slides to rescan at higher rez if needed.</p>

 

<p>No one can tell you what you want, but I can tell you what I use. </p>

<p>If you want to capture most of the information in a 35mm frame, a 6 MP scan will suffice. If you want to capture all of the information in a 35mm frame, then you need 40 to 50 MP, but you don't get that much additional information for all those additional pixels. </p>

<p>I have two film scanners:</p>

<ul>

<li>Kodak RFS 3570 provides 6 MP</li>

<li>Nikon Coolscan III provides about 8 MP</li>

</ul>

<p>I have used them to scan a variety of film images. The largest print I've made from one of these files was 20x30 inches. It looks very good when viewed from an appropriate distance. If I had a scanner that delivered 12 MP, I would probably use them, but I'm not willing to pay the big bucks to get images with barely noticeable differences.</p>

<p>I use jpeg files with "high" quality (at least 8 on the 12 point scale). If you look at individual pixels, you can see differences from TIFS, but at any reasonable viewing distance, I can't see the difference.</p>

<p>I do not think jpg is the way to go. Looking at a 6m jpg on an HD TV is a terrible metric because HD TV is not really HD...a marketing term at best but really, it sucks compared to still photography abilities.</p>

<p>Also jpg does not offer more then 8 bit color which sucks.</p>

<p>Better to scan the negatives at the highest resolution you can and at at least 16 bit color. It matters a lot, don't let anyone tell you different.</p>

<p>I scan my negatives with a CoolScan 5000 at 4000 dpi and at 16 bit color, and this is the bear minimum IMHO.</p>

<p>Dan, <br>

I agree that HD TV is not a stringent way to view images, Help me understand--under what conditions can you see the difference between 8 bit and 16 bit images? </p>

<p>For a well-exposed negative or slide, I scan 8-bit. If there's an exposure problem, I scan 16-bit, so I don't risk posterization when applying strong greyscale curves. This is especially important if the exposure problems are in the shadows, as the universal use of gamma curves means that not many density levels are allocated to the shadows.<br>

For output, I doubt there's any device where 8-bit of 16-bit makes a visible difference.<br>

TS, as for quality -- you'll quickly find that paying someone to do anything better than the normal mini-lab scans for 4x6 prints gets expensive fast.</p>

 

<p>A normal lab scan is about 5 or 6mb scan. It will print out a 4x6 at 300dpi. I have no problems printing out at 8x12 by increasing resolution in photoshop. Having lab scans that are larger gets expensive and you would only want to do that on a frame by frame basis. If you have a nice scanner and do not mind spending your evenings scanning then larger is an option. For myself I just use the lab scans. If I feel like I need a larger file occasionally then I will scan it myself. There is a lot of ways of going about it and I think it is just something you decide what works for you.</p>

<p>Thank-you for all the very useful information. Helps a lot.</p>

<p>to Ron Andrews,</p>

<p>I have an RFS-3570 but am missing the calibration mask, which are impossible to get. Can you describe the mask and perhaps I can figure out how to build one?</p>

<p>Pictures and measurements would be fantastic.</p>

<p>I would love to be able to use the beast.</p>

<p>Thank you! - Bill Lynch, wblynch at hotmail dot com</p>

<p>** I apologize for hijacking the thread</p>