Scanning negatives and MP equivalents?

[cps]

Forgive me if the title of the question doesn't make much sense, but I have a

few pictures I'm considering submitting to a small local magazine and they now

only accept digital submissions...part of their guidelines are 6MP or greater,

the question I have is if I have a few negs (or slides for that matter) scanned

and then submit them that way, just what size should I scan them at to equal

6MP? I'm totally new to all the digital stuff so much of this is new to me. I'm

not a professional photographer either, but have submitted a few things over the

years and just have fun doing it. But with everyone going digital now its a

different ball game, and since I only do this from time to time I'm not up on

this like I should be. I have a 5MP digicam and its pixel resolution is

2592X1944, but what is the standard for 6MP? And how does that go with scanning

a negative? Or does it? (sorry, I only have a flatbed scanner, and to get a

"real" scan of a slide or a neg I'll take it to a lab)

 

Like I said, I only want to send these pics in for fun anyways, it's not like

I'm making big $$$ from it, but I always enjoy seeing something of mine in a

magazine, even just a small local one.

[mike_kim]

There is no standard 6MP size. Most digital SLRs have 3:2 or 4:3 as their horizontal vs vertical pixel ratios. Since you are scanning the slides, 3:2 aspect ratio scan would make more sense to you.

 

Frankly, typical film scanners do offer 1200, 2400 or 4000dpi optical resolutions. Since 35mm film is 36mmx25mm (1.42" x 0.94"), typical 35mm negative scan can be around 5680 x 3760 pixels at 21MP. Similarily, 2400dpi scan will result in around 7.7MP and 1200dpi at 1.93MP. I think if you scan your film using 2400dpi resolution, you should produce acceptable 6 plus Mega Pixel scan for the publication.

 

FYI, Canon 10D Digital SLR had 3072 x 2048 and it was 6.3MP (3:2 ratio). As long as your final scans exceed 3000 x 2000 and you should be fine.

[mike_kim]

Opps, there was a typo. Film size should read 36mmx24mm.

[emre]

I think a 4000ppi negative is equivalent to a 6MP DSLR and a 4000ppi positive is equivalent to a 10MP DSLR. This is with a film scanner. Consumer flatbeds do not have that high a true resolution; they probably max out at around 2000ppi.

[Ed_Ingold]

Most DSLR (35mm footprint) have a 2:3 aspect ratio - the same as 35mm film. A nominal 6MP camera would have 2000 x 3000 pixels. The true size may vary somewhat from this ideal value. Most P&S cameras and some DSLRs have a different aspect ratio, such as 4:3.

 

If you scan a 35mm negative (or slide) at 2000 ppi, you will get about 6MP. This is about the useful limit for a good flatbed (e.g., Epson V700), and about a quarter the size that a Nikon LS-50 (or LS-5000) can deliver at 4000 ppi. You can specify 2000 ppi in a Nikon scanner, and still get better quality than from a V700.

 

Because there are three colors for each pixel (RGB or CMY), the usual size of an uncompressed, 6MP file is 18MB. If the camera or scanner puts out a file with more than 8 bits/channel, the file size is twice as large. This is because each pixel channel requires a 16-bit word.

 

A compressed image file, like a JPEG file, is much smaller - typically under 8MB, depending on the (optional) compression factor and the amount of detail in the image (more detail requires more space). JPEGs are limited to 8 bits/channel.

[david_littleboy__tokyo__ja]

What Edward said: don't fool around, get one of the current Nikon scanners.

 

Where I disagree is that I'd recommend scanning at 4000 ppi with just ICE. Then use Neat Image or Noise Ninja or the like (or even Photoshop CS3) to remove noise, crop to taste, and downsample to 2000 x 3000, and you'll have images that are slightly better than what 6MP dSLRs produce. Assuming you used good film, such as Velvia or Provia 100F or Reala. With consumer negative films, your milage will vary.

[jtk]

From what I've seen it takes a 5D to *consistently* approximate 4000ppi scans of 35mm.

 

Mere 8-10MP 1.5 ratio DSLRs can be superb in color, almost always telegraph their digital nature in B&W prints. Not equal to good film if you apply traditional B&W or color negative aesthetics, though their inevitable excess sharpening signature may be attractive in some situations. Aesthetics change.

 

Type of film is irrelevant, it's all good when used well...the limiting factor is virtually always the operator and his optics, particularly if he is using a DSLR's typical zooming Coca Cola bottle.