help on scan/print

[butch]

I am having trouble getting a decent print. I use either an Epsom 700V or a KM Elite 5400 to scan Fuji processed slides or my Diafine'd Tri-X or HP-5+. I print to a Canon i9900. I'm getting a sort of smeared bunch of small over lapping squares over various areas of the scan, probably most frequent along straight lines, like along a long stem of grass. I dont know what to do to fix it, I don't even know what to call it. I have PS Elements 3 and the programs that come with the scanners. You help would be appreciated.

 

[planetjoe]

This sounds very much like some kind of resolution mismatch - the "jaggies" you're seeing are a form on pixelization (aliasing) along straight, usually diagonal, contrast edges. Perhaps there's a resolution setting, either in the scan, processing, or printing step. I am assuming you're talking about the appearance of a final print in this case. From the sound of things, there doesn't seem to be as much image data getting to the final print as there should be for the size you're printing at.

In my experience, an 8-bit grayscale b&w image destined for printing to 4x6 inches should be set at an equivalent resolution of 200-300 dpi for "very good" quality. That is, the final "image size" should be in the vicinity of 1200x1800 px. A high-quality jpeg at that resolution will have a filesize of between 200 and 600 kb, I think. Someone here can correct me if I'm off my rocker.

I'm not sure where the mismatch might be occurring - I do know that there's a lot of misunderstanding out there over "dots per inch" and how this quantity might or might not affect printing (my understanding is that it does not; only the size of the document and total pixel count actually matter). In my experience, print drivers/dialog boxes don't always tell a clear story.

I'm sure some folks here will recommend you try Vuescan (www.hamrick.com) to drive your scanners, and I'd second that opinion. It is, however, a rather full-featured piece of software, and so you're best off figuring out this issue before changing software packages. But who knows? Maybe it's the scanner software that's giving you fits currently. Vuescan has a free trial.

Sorry I can't offer a definitive solution. Good luck.


Cheers,
--joe.

 

[Gid]

Sounds like pixelation - you're probably trying to print large with a very small file. I use the Epson 4990 and the interface is more or less the same as the V700.

First step is to decide how big you want to print. Lets say, for example, that you want to print a 10" x 8" from a 35mm slide and you want to print at 300 dpi (you can print at a lower dpi, but if you want "good" quality then 300 dpi is recognised as the optimum, generally). Your scan will need to be 3000 pixels x 2400 pixels to print a 10 x 8 at 300 dpi (10x300 = 3000 and 8x300 = 2400). Now a 35mm slide is slightly less that 36mm x 24mm which is approximately 1.4 inches x 0.9 inches. To work out your required scanning resolution divide the 3000 pixels you'll need for the long side of your print by 1.4 which will give you a scanning resolution of 2142 dpi. Use the next higher value supported by your scanner, which in the case of the Epson is 2400. Select this value from the resolution drop down box. That should do the trick. This will give you a 1.4 x 0.9 inch image at 2400 dpi - you will then need to go to image size in PS, disable resample and type in 300 instead of 2400 dpi. Now, this is the long winded version on purpose so you understand the process.

The easiest way to achieve your goal using the Epson is to let the scanning software do the maths - select 300 from the resolution drop down box and select 8" x 10" from the target size drop down (or any target size you want) and then hit scan.

If I have been teaching granny to suck eggs, then, humble apologies.

 

[butch]

Thanks, so much, you guys. At least I have some hope now. Previously, I felt that I was spinning my wheels.

 

[oscroft]

I'm getting a sort of smeared bunch of small over lapping squares over various areas of the scan,

Too much jpg compression may also be the problem (especially if it's only happening in some areas and not others). If your scanner software has a quality/compression setting, set it to 100% quality, or if any subsequent processing software you use has a similar setting (usually when you Save ot Save As), set that to 100% quality.

Best,

 

[Gid]

Good point on Jpeg compression. As a general rule, you should save your "raw" scans as Tiffs. No lossy compression is applied to Tiffs and you can always go back to the original Tiff if you decide to apply different processing. Once you're happy with the image save this again as a Tiff (with new name of course). You can then resize and save as Jpegs for emailing, web etc, but you'll always have the original scan and the original finished image with no compression.