joekraft wrote:
If I wanted to compare a scanned photo to a 5D file, what would be the most similar dpi to use for scanning?
Thinking this through right now:
4368 X 2912 pixels.
36 X 24mm
1.42" X .95"
~ 3070 pixels/in = 3070 dpi?
Is that right? Scan it at something around 3000-3100 for an even comparison?
I think you should scan at max resolution and downsize it. All 7200dpi film scanners' that I've considered have effective resolution of about less than 3500dpi.
If you are scanning at 3000dpi setting, the actual resolution maybe much less.
Those flatbed scanners' effective resolutions are typically less than half of the rated value. The canonscan 8800F is only about 1600dpi.
You should be able to search the internet for the detailed test results.
I'll give it a shot. But, I'm not optimistic. At 2400 dpi, it takes me about 4 minutes soup-to-nuts to scan a frame that comes in around 80Mb. My software goes up to 12,800. I'll give it a shot, but if it takes 7 or 8 minutes to scan one frame, I'm not going to be able to scan much
Thrice, if I have to scan ~3100 for a 5D MkI, wouldn't I have to scan at a much higher dpi to match a MkII pixel density?
If anyone has any thoughts on faster scanning please let me hear them. I have a V500 hooked up via USB2 to the back of my chassis. I looked and didn't see a firewire port. I suppose a faster processor and RAM may help, and that was sort of on the horizon already.
"I'll give it a shot. But, I'm not optimistic. At 2400 dpi, it takes me about 4 minutes soup-to-nuts to scan a frame that comes in around 80Mb. My software goes up to 12,800. I'll give it a shot, but if it takes 7 or 8 minutes to scan one frame, I'm not going to be able to scan much"
That 12800 is an interpolated number and not the hardware resolution. There is no sense in scanning beyond the hardware resolution of your particular scanner.
"Thrice, if I have to scan ~3100 for a 5D MkI, wouldn't I have to scan at a much higher dpi to match a MkII pixel density?"
It depends on the film you are scanning, whether or not the film actually HAS any additional detail and thirdly, whether or not your scanner can actually record that detail.
"If anyone has any thoughts on faster scanning please let me hear them. I have a V500 hooked up via USB2 to the back of my chassis. I looked and didn't see a firewire port. I suppose a faster processor and RAM may help, and that was sort of on the horizon already."
The bus is not the bottleneck. Scanners typically are not all that fast and there is nothing you can do to speed them up. For me, seven minutes for a 4000 ppi scan is blazingly fast on my drum scanner, and it's three times faster than the previous model I used. Of course, it's up to 28 minutes for an true optical 8000 ppi scan.
If you got a V500, you probably won't get much more than 2000 dpi out of the scan. Try scanning at 4000 (or 4800 dpi or whatever is an option) then down sample to 2000.
If you are doing this for the real keepers or a one off comparison, try a couple different resolutions and downsamplings and figure out what works best. If you are just doing it to post some shots on the web, stick with 2400 and go at it.
joekraft wrote:
Thrice, if I have to scan ~3100 for a 5D MkI, wouldn't I have to scan at a much higher dpi to match a MkII pixel density?
Don't bother, the MkII will look better whatever resolution you scan a 35mm frame if you are scanning on a flatbed like the V500.
If anyone has any thoughts on faster scanning please let me hear them. I have a V500 hooked up via USB2 to the back of my chassis. I looked and didn't see a firewire port. I suppose a faster processor and RAM may help, and that was sort of on the horizon already.
My V700 is almost twice as fast over firewire than USB2. Don't know why, it just is and that probably doesn't help you with your USB-only V500.
As for how to go about the scans, the thing with home scanning is that you scan a roll at low resolution in like 5 minutes and then only scan at the high res the stuff you really want (or you just take it to a lab for drum scanning, if you really must have it top notch). Otherwise you are looking at 3-4 hours just to scan a 36-exp roll at full resolution.
I would forget flatbed scanners and use a film scanner. It will come out looking much better. Remember that the dynamic range will affect the look of the details more than the resolution.
Thanks for the input. I need to hit the books a little bit. I never paid much attention to anything about scanning, because my usage was limited.
However, I need to add some additional facts: 1) Using 120 film. Haven't picked up a 35mm body, yet. 2) I don't have the $$ for a nice film scanner such as the one linked above. Could *maybe* swing a V700 if I could sell the 500, but a huge investment is not doable.
Using 120 film (645 format as I recall) you should be able to reach 5D resolution through this scanning system, but the scanner is definitely the weak link. Just scan at 2400ppi and resize in photoshop to match the dimensions of the 5D if you want to compare your scanner output versus the 5D.
I don't think you would expect to see a massive improvement by moving to the V700. The reason to choose the V700 is when you have a need to scan larger film formats or wish to scan more frames of film on one setup of the scanner.
Put DPI out of your head, it serves no purpose here.
The usual advice is to scan at the hardware's maximum optical (aka 'real') resolution. At higher settings, the software is simply interpolating 'junk' pixels. At lower resolutions you may run in to aliasing, although scanning at 1/2, 1/3, 1/4 etc. should be OK.
You can then re-size to match your target resolution.
Also keep in mind that "not all megapixels are created equal!" A 2K/inch scan on an Imacon will utterly kill the output from any consumer-range flatbed, regardless of how many 'DPI' you dial in.
Good choice on the 120 film. What's your goal here? Prints? or web use? that makes a big difference. Forget flatbeds if you can. they are the road to nowhere, even with 120.
Unless you want to become an expert at scanning it may make more sense to just send out what you want scanned to a pro color house. Faster, and likely better than you can do at home with anything less than say a nikon 9000.
Better yet, set up a home darkroom and do your own prints, which if you can, is easily the best way to make prints from film.
I use the V500 to scan my 120 film and it does it wonderfully. I typically scan at 2400ppi. Gives me HUGE files which certainly are a match for my 5D's files. I've been very happy with it (aside from the slow scanning and crappy film holders).
I have an Epson 4990... reasonably well respected for MF... but 35mm scans from Coolscan V kill 6x9 negative scans from the Epson... really crappy. Does fine for moderate size prints though and it was dirt cheap at discontinued pricing.
Personally, if you do this comparison you have to take it out to prints to be meaningful. I did this with my Coolscan V and BW400CN vs 5D b&w conversion and *I* prefered the look of the film scan... a 5DII will give smoother images, but I think I would still prefer the look of my film scans for my normally not gigantic prints...
If you intent is to prove digital is better than film, it's easy to do for internet viewing...
If you are just shooting test targets digital will beat film on screen for smoothness, shooting real scenes the tonal depth and dmax of film can be more important...
mh2000 wrote:
If you are just shooting test targets digital will beat film on screen for smoothness, shooting real scenes the tonal depth and dmax of film can be more important...
What, don't you have framed test targets hanging in your place?
Well, I don't want to cut off the discussion at all, because there is food for thought here, but let me clarify that I was just curious about the comparison.
I was zooming up on some scans in Lightroom, looking at the zoom crop in the preview, and it just got me wondering how you would compare apples to apples, but I'm really not all that interested in pixel peeping.
However, my intended workflow for now is to scan the images, and print them out via the computer. Eventually, I'd very much like to make my own prints. Hell, I'd like to make collodion wet plates
So in the meantime, I very much appreciate the advice on to best scan for purposes of printing. I'd really like to get some larger prints from my Mamiya, and I have a 6 X 7 body that I am going to want to make prints from.
