"Efficient" scanning of MF film on the Epson 4870.

[kosmoskatten]

Hi folks,

I just got the Epson 4870 for scanning my 6x6 negs. Initial results look

promising, I use Epson scan based on peoples comments and it works well,

or well, it works. Since the documentation and online help on the Epson is

somewhat lacking I seek assistance from any user who has worked it out

already.

 

Output will be on Epson 2200, max square size on A3+ or roughly 12.5"x12.5"

or cropped to fit A3+ paper.

 

What is the "true" optical resolution of the 4870? Given the above output sizes

I am looking to find an optimum, preferrably non-interpolated setting for the

initial scan. What settings are "optical" in the upper range?

I find no need to scan at higher res than necessary for the 12.5" square output

but wouldn't want to sacrifice quality. To save time for dust spotting I will be

using the ICE function.

 

There is an option in the scanning menu for "output size", if I insert my values,

say 12.5"x12.5" at 300dpi will the software work out the resolution needed by

means of optical resolution or up/downsampling from the nearest value?

 

Also, the histogram settings are somewhat confusing. If I want a "raw scan"

with maximum information and set levels in PS CS how do I go about it?

On an Imacon I have used occasionally (great stuff) you just set the sliders to

0/128/255 and get pretty much all of it but if I try the same on Epson scan the

preview just blackens out ... ??? I must be doing something wrong, right?

 

Last but not least, has anyone used Dougs film holders on the 4870 - I was

thinking of getting one.

 

All HELP is appreciated, thanks

Henrik

[nikos peri]

AM no expert, although I have been running the 4870 (read: ripping my hair out on occasion) with MF and LF for a few months now. <p>I've heard here that the true optical resolution is about 2000 dpi, but I couldn't confirm or deny that. <p>As for the ICE in order to save time, you will probably soon realize that you won't save any time with it: the scanner is slooooooow! <p>

The preview image blackening out seems to be an issue with buffer memory; either in your PC (most likely) or the scanner. There have been reported bugs with the scanner buffer memory when using the Thumbnail preview at max resolution. The workaround is to manually select the scan area and do only one scan at a time. <p>

I gave up on the semi-auto settings for output size and scan resolution, precisely because I couldn't figure out what exactly the scanner was doing. I just leave the size as "original" and select my resolution and then adjust my output size in PS - where I do know what the software is up to.<p>

The histograms are a bit hit & miss IMO, with highlight clipping often the norm. Again, I prefer to scan with a greater range (i.e. NOT clip the data) and adjust in PS.<p>

As for the neg holder, Dougs look like a great product giving you better flatness, but I can't complain about the MF set Epson put in. The 35mm holders on the other hand are really lame.<p>

Sorry I can't be of more specific help but I'll be watching the thread as I'm sure I'll learn alot too!

[kosmoskatten]

Hi Nicola,

thanks for your input. I have done some testscans now and the digital ICE is

ever so sloooow... I am trying out the various dust removals as well.

Also I suspect that ICE creates some minor artefacts along the way. In small

shadowdetails (small waves on a picture with a ferry) the output is better

when ICE is disabled. Anyone?

 

Another photo.net poster said the optical resolution is around 1700dpi on the

4870. (According to a magazine - and as he himself stated; don't believe

everything you read) Whether it's true or not I'd like some kind of confirmation

on this.

 

Best results so far is scan as "original" 2400dpi and not "intented output size"

(in my case 12.5x12.5" at 300dpi) with histograms set at a wide margin in

Epson scan and levels set in PS CS and no ICE.

Looks very promising.

 

Epson bonus/included in the package for no extra charge;

I have three big spots under the flat bed glass that are likely to stick around...

(Not minor dust specks - more like a seagulls perched on the waves on the

scan) I'd hate to start messing with that.

 

All input welcome.

[jack paradise]

According to german magazine Color Foto and Ct' the real resolution is somewhere is less than 2000 dpi.

 

Want confirmation ? Scan a negative at 2400, 3200 and 4800 and print to A3+ size.

[tom_halfhill]

Henke, don't be confused by the previous answers to your question. The true optical resolution of the Epson 4870 is 4800 dpi. That means if you scan something at 4800 dpi, the output image will have 4,800 dots (pixels) per inch. The Epson 4870 doesn't need to interpolate pixels to generate that result. At higher scan resolutions, the scanner will use software interpolation, because the true optical resolution is 4800 dpi (maximum).

 

When people say the "true" resolution is 2000 dpi or 3000 dpi or something less than 4800 dpi, they're not really talking about the scanner's output resolution. They're talking about the ability of the scanner's optics to render fine detail. These are two completely different things. Optical resolution is better expressed in lines per millimeter and measured with a test chart. It's confusing to associate dpi with optical-system resolution, because dpi means "dots per inch." And the maximum number of dots per inch the Epson 4870 can produce without software interpolation is 4,800.

 

Think of this analogy. A particular type of film has an inherent resolution. For example, a slow ISO 25 film like Kodak Tech Pan will have a much higher inherent resolution than ISO 400 Tri-X. A film's resolution is sort of like scanner resolution. It represents the maximum possible resolution if everything else is perfect. But if you shoot the film in a cheap camera with a bad lens, you'll get a fuzzy picture, even with Tech Pan. That's because the optical system (camera and lens) isn't taking advantage of the film's inherent resolution. Put the same film in a good camera, and you'll get a sharper picture.

 

The Epson 4870's maximum optical resolution of 4800 dpi is like the film's inherent resolution. But the sharpness of the output image depends on the scanner's optical system. Another 4800-dpi scanner with better optics would make a sharper output image. But both images will be 4800 dpi.

 

Anyway, don't worry if you don't understand it. The most important thing is setting the scanner's resolution to produce the output image you need. And that is simple.

 

Let's say you want to make a print at 300 dpi (high quality for an inkjet printer). Multiply the enlargement factor of your desired print size by 300 to find the correct scanning resolution. For example, let's say you want to make an 8x10-inch print from a 2-1/4 inch negative (6x6cm). That's roughly a 4x enlargement. So you multiply 4 times 300 = 1200 dpi. You need to scan the negative at 1200 dpi to get an output image large enough to print at 8x10 inches at 300 dpi.

 

If you set the "output size" in the Epson scanner software at your desired print size, and then set the output resolution at 300 dpi, the software will do the math for you.

 

As for the histogram settings, start with the automatic settings. My experience is that they do a pretty good job on the Epson 4870.

[kosmoskatten]

Jack; I am short of ink at the moment and the reason for asking here was that I

wouldn't have to go to the lengths of printing A3 sized prints - if someone had

done the job for me already ;-). Otherwise yes, a good idea.

 

Tom, thanks for clarifying what I somehow knew deep down regarding the

true resolution on Epson 4870. Yes the Auto mode works fairly well on the

Epson but having worked on Imacon scanners (where I had the choice of true

optical res or interpolated) I find that I can tweak more in PS CS.

 

All in all I am very pleased with the product so far. Just got word from Doug

Hansen that Silverfast SE can be upgraded to accommodate RAW scans in

16/48 bit and now works with ICE in RAW. Sounds good.

 

Thanks again, Henrik

[jem]

As a quick note, my Imacon resolves more detail at 800 PPI from 6 by 7 film than my Epson 4870 at 4800 PPI. At 1600 PPI the imacon absolutely trounces the Epson.

 

I find myself wondering why bother shooting MF if you're going to scan on an Epson. 35mm scanned on the Nikon Coolscan V resolves more detail!

[kosmoskatten]

Hi Jeremy, yep, with acccess to an Imacon one could wonder what the ... I am

doing with the Epson 4870...

Problem is I don't have it at home, and have precious little time with the

Imacon at work. I believe the Imacons ARE the best, but for home MF printing

and good scanning and postprocessing (not too aggressive sharpening and

some Local contrast enhancement) the Epson seems to deliver very pleasing

results up to A3. I have a bundle of Fine Art papers to print on and with some

minor work the input "matches" same size Imacon scans fairly well. Not as

good as but very good still.

 

Comparing a huge 35mm scan from a Nikon Coolscan to the same output

size as a 6x6 scan in my opinion the MF scan wins hands down - it is not a

sharpness-down-to-resolving-grain issue - the scans from MF are smoother

and with proper sharpening/local contrast enhancement they print better.

All my thinking of course, though I have had a few (Contax) G2 negs Imacon

scanned (Fuji Reala neg film) and output to A3 and they look awesome but

that's pushing it. I would not scan 35mm on the Epson 4870 at all - doesn't

seem to yield nowhere near the same quality as some mid end scanners.

 

Anyway, I have gotten it right now and the scans look very good - too bad I am

out of ink for the printer...

 

Cheers all for your input,

Henke

[kosmoskatten]

Normally I print 10"x10"s (25.4x25.4cm) and smaller sizes and crops at the

Fuji Frontier at work. It's just for some other stuff, like old negs and some

landscape work I got the Epson for.

I only shoot MF with a Hasselblad Superwide (fixed 38/4.5 lens) hence my not

buying into a dedicated MF filmscanner - this was the cheap and (seemingly)

workable solution to my needs.