Bed vs Drum Scan

[koniczech]

Hi all,

I was wondering, how does a drum scan compare to my bed scanner? I noticed that the resolution goes up to 1,280,000 dpi (haven't had the immense amount of time to try it yet). If the bed was very clean and I scanned my film as such, would this actually make this comparable to a drum scan? Or is this just to enlarge it to the size of Montana when plotted?

I've heard about the color capacity of drum scanning... is that all it improves?

Thanks,
koniczech

 

[Bob Michaels]

The extra $49,500 that the drum scanner cost over what you probably paid for your flatbed does get better optics and electronics. Now one can debate if they 100 times better but they are spectacular.

Of course you can do scans on your flatbed that will serve you very well.

But I have stuck my nose up to some 20"x30" prints made from 35mm chromes where cost was not a factor (Alex Webb / Magnum prints) and I was quite impressed with the quality. I have been scanning with very good film scanners for almost ten years and I cannot do that well. Nor can anyone else that I know. It is a rare day where I credit the equipment but that had to be the drum scanner.

 

[aizan]

general rule of thumb is that flatbeds can make a good 3x enlargement, film scanners up to 5x, and drum scanners 8x. dynamic range will increase, too.

 

[Ezzie]

I used a link on the front page of the Largeformatphotograhyforum page to compare scans from a range of scanners the best consumer flatbed on the list was without a doubt the Epson v750. It was also nearly as good as many of the dedicated film scanners too. But it was nowhere near to lets say an Imacon 949. Now that blew me away. Will I buy one? No, but I will look to have scans sent out to match such quality when need be. I'll be getting a v700 for daily use I think.

The comparison page: http://www.largeformatphotography.info/scan-comparison/

 

[Jamie123]

Hi all,

I was wondering, how does a drum scan compare to my bed scanner? I noticed that the resolution goes up to 1,280,000 dpi (haven't had the immense amount of time to try it yet). If the bed was very clean and I scanned my film as such, would this actually make this comparable to a drum scan? Or is this just to enlarge it to the size of Montana when plotted?

I've heard about the color capacity of drum scanning... is that all it improves?

Thanks,
koniczech

As Bob says, there are professional drum scanners that cost many thousand dollars (up to $50'000) and their quality may be comparable to drum scanners. Also keep in mind that there are many differently sized and priced drum scanners. There are drum scanners that fit on a regular table and then there are also drum scanners tha fill half a room. The latter used to cost up to $500'000+ 'back in the day'.

 

[Avotius]

Consumer scanners use image interpolation when they are talking about those really high DPI's. The flatbed I had before maxed out at 2400 and the quality was pretty poor.

Then I used to get my film scanned on one of thos nifty fuji work station type machines and the quality was great. 6x6 negative, highest resolution bmp scan, thought it was all I would ever need. Then I realized the shortcomings of the machine like making color fringing much worse than other machines and sometime rather uneven resolution.

Recently I have had scans done on a Creo scanner and it is better than the Fuji, the results are more consistant. Soon I will be trying one of those "half room sized" drum scanners with my recent large format shots, I have high hopes!

 

[Jamie123]

Soon I will be trying one of those "half room sized" drum scanners with my recent large format shots, I have high hopes!

Even with those scanners the quality can vary. I once was in the scanning room of a big stock photo agency (the one that rhymes with Betty) and they had three ''half room sized' drum scanners and a Hasselblad X5 Flextight. The operator told me they use all of them for different reasons. One handles slides better while the other does better with neg film. One's better for color, the other's better for bw.

 

[fotomik]

Also never forget that the guys running the scanners make half the image... Getting that good scan from a drum takes a bit more than just pressing a button marked "SCAN".

 

[bagdadchild]

Last edited by bagdadchild : 06-05-2010 at 07:30.

 

[tammons]

general rule of thumb is that flatbeds can make a good 3x enlargement, film scanners up to 5x, and drum scanners 8x. dynamic range will increase, too.

Not even close to correct.

With an Epson 700/750 6-8x is about max depending on the film, and if you have a good scanner.

With a good 4000 dpi drum scan with super sharp 80++ lp/mm film printing on a lightjet at 4lp/mm IE 208 dpi you can enlarge about 15-20X.

A drum scanner keeps the film perfectly flat.
You typically wet mount film on a drum scanner, but you can wet mount on a flatbed or a Nikon 9000 with the right holder.
With a drum scan the lens is not looking through a piece if glass (or multiple glass)

A drum scanner samples RGB, all 3 colors at every pixel location.
A drum scanner has an adjustable aperture in the lens and you can basically tune in softness to help with grain.
A drum scanner has a focusing lens.

A drum scanner is slow.

 

[starless]

I used a link on the front page of the Largeformatphotograhyforum page to compare scans from a range of scanners the best consumer flatbed on the list was without a doubt the Epson v750. It was also nearly as good as many of the dedicated film scanners too. But it was nowhere near to lets say an Imacon 949. Now that blew me away. Will I buy one? No, but I will look to have scans sent out to match such quality when need be. I'll be getting a v700 for daily use I think.

The comparison page: http://www.largeformatphotography.info/scan-comparison/

And Imacons are not even drum scanners, though latest models probably come closer to a real drum scan.

The main advantage of drum scanners is not only resolution but dynamic range. However a drum scanner doesn't scan by itself. The operator is as important as the hardware. I can show you scans on Imacon and Tango drum scanners that looks crap compared to the same ones I did on a $100 Epson flatbed.