Need advise on Imacon scans.

1.0 ) 1. I understand 72dpi is good enough for screen publishing, some 200dpi is for inkjet prints and 300dpi for common polygraphic reproduction

Those are reproduction resolution numbers .

2.) but what is the use of, say, 600dpi and up to 4000dpi?

Those are the resolution you actually scan at . A 35mm slide is approximately 1 x 1.5 inches, so if you scanned a slide at 300ppi, ehn you went to print it you could onl yreproduce it 1 x 1.5 inches @ 300dpi. But if you needed t oprint it at 10 x 15 inches at 300dpi (3000x 4500 ) you'd need to scan it at at least 3200 ppi .

3.) 8 bits = 256 gradations per red, green and Blue component. ifyou needto start manipualting the scanned image -- adjusting brightness, contrast, sharpening for printing, or even just rotating -- you may quickly start to see "banding" --where you get visible dramatic changes in a continuous color -like in a sky.

16 bpc has more than 65,000 gradations per R G & B channels: much smoother transitions in color and tonality. Additionally using 16 bpc allows you to use the Pro Photo color space which is large enough not to clip the saturated colors in your Fuji and Kodak slides.

Thank you, Ellis. Valueable information for me.

Let me understand it right. If I have 35mm color slide scanned in Imacon into TIFF, 300dpi, RGB, 8bpc, some 30MB file size, it is not a quolity product which a graphic designer can be interested to buy in order to use it for quolity polygraphic reproduction in final size of some 10''X15''?

Does it has to be TIFF, 4000dpi, RGB, 16bcp of some 500Mb - 1Gb file size to make it a universal commercial product?

Or to put it in another way. What kind of file do I need from Imacon to make top quolity poster in 10''X15'' polygraphically from 35mm slide?

For 10x15 inches, if printed at 300dpi you need 3000x4500 pixel original file or so. Scanning at 4000dpi would give you more than enough info to do this. As Ellis said 16 bit gives you more flexibility for processing and using a larger color space without banding or clipping colors. That comes out to about a 120mb file from 35mm, not 500mb.

You certainly would not use jpeg for this as it's compressed and lossy and 8 bit only. TIFF, PSD and other formats are lossless. A designer could make a 10x15 out of almost anything but would they choose your file if it's technically inferior?

For more basics on scanning and digital files try scantips.com

...If I have 35mm color slide scanned in Imacon into TIFF, 300dpi, RGB, 8bpc, some 30MB file size...

...at the 1" x 1.5" dimensions Ellis used, this would give you a 135KB (0.135 MB) file not a 30MB file

[at] ...4000dpi, RGB, 16bcp... this would give you a 48MB file not a 500Mb - 1Gb file

"[at] ...4000dpi, RGB, 16bcp... this would give you a 48MB file not a 500Mb - 1Gb file"

35mm film at 4000dpi 16bcp gives you 120-135mb file (depending on how much of the area around the film your scanner captures.) At 8bcp you are closer to 48mb file.

Thanks, Roger. Yes. I start to understand better. TIFF vs. JPEG&lossless issues are understud.

The scans I had earlier from same machine were usually TIFFfiles, 8bpc RGB, some 9X12in or A4 dimention, 300dpi and filled up to 30Mb. It was full frame scans of 35mm slide mounted in 35mm Imacon holder which cropes it down to some 96% of fully exposed film area. These files were up to 30Mb. Now I have tryed to scan the same, set at 16bpc and 600dpi and it gives me a file of some 120Mb. The 4000dpi remains to be tryed on.

All these brings me to the next group of questions. Then I am to start the scan I have first screen of Flexicolor software which runs the scanner. It prompts me to choose:

1. file size - 2. dimentions - 3. resolution -

and the color deepth somewhere.

I see some contradiction between 1 and 2-3. If I order TIFF file size 50Mb and set 2 at 20X30in, 3 at 4000dpi and color deepth at 16bpc the machine will has to squise 2-3Gb of info into 50Mb file somehow or what?

Or should I leave file size field unspecified?

Does the consiquent rotation of original scan in landscape orientation into vertical affect quolity? Should landscape shot be scaned in horizontal holder in order to obtain best quolity?

Do curve adjustment in Flexicolor affect the scanning or only adjust scanned data?

Thank your all for kind attention and suggestions. -Ilia.

I would use these settings to create a digital negative:

Setup = RGB Standard

Frame = 35 mm Slide (Are you using the 24x36x2 holder?)

Mode = RGB 16 bit

PPI = Select the highest optical resolution you will ever need (this will produce a non-interpolated file)

Just use the default dimensions that are set when you select the frame and don't worry about file size.

Then use Flexcolor or Photoshop to resize the scanned image for specific jobs.

It doesn't affect the scan if you rotate the preview image. On the latest imacon (Hasselblad X5), the vertical opening is necessary for the highest resolution. I've read somewhere that the horizontal frame allows more light to pass through the film during scanning, but I'm not sure if this is a big advantage.

Alternatively, you can create a 3f file. This is a raw scan, similar to a raw file from a digital camera, and can be opened in Photoshop.

Also, I turn sharpening off as the amount can vary with different print media.

You should locate flexcolor documentaion. I found some on the internet.

Thanks New Haven. It makes sense.

... (Are you using the 24x36x2 holder?)

There are 2 or 3 holders with 35mm openings on the board, some vertical, some horizontal, not each are accepted in machine as it is setup per now. Most of my scans are 35mm slides made in one of these 24x36X2 holders. Few are made in 6X6 holder with hand made extra screen in order to get more then 100% of exposed area. I also scan some b/w and color negatives, most in 35mm as per now. The machine is Imacon Flextight 848 is not my own but one I may have access to sometimes and together with an employed operator who is far from being an expert as it seems.

... PPI = Select the highest optical resolution you will ever need (this will produce a non-interpolated file).

Does it mean the highest possible and available for selection in PPI window or is it Optical resolution window? Say 4200ppi or some 6000ppi?

Can you give me an estimation of file size and dimentions to be produced in this way from 35mm slide at max. optical resolution of some 6000ppi?

I was searching for Flexicolor documentation on the Net but couldnt find any. Will appreciate some links.

Thanks. -Ilia.

My 35mm scans at 6300 ppi are approximately 310 MB. At 8000 ppi they are about 590 MB. The optical resolutions are selected from the PPI popup and are underlined. The available optical resolutions will be different depending on the holder and opening orientation. I rent an X5 so I scan at 8000 ppi, although I certainly don't need that much resolution as my largest prints so far are 11x17. I'm sure there is an upper limit beyond which more scanning resolution is of limited or no value, but I haven't done any testing.

http://www.hasselblad.jp/media/139772/flexcolor_scanner_uk.pdf

http://www.photoworkshop.com/rooms3d/imacon_tutorials

Thanks alot.

A asume now that to make a good 12"x16" print at 300dpi I need original file from Imacon of 4800ppi and in 12"x16" dimention, size suppose to be about 200Mb. Will try to make one next week.

Another question. Does your Imacon generated file inholding EXIF information which says: Imacon MODEL, software: FlexColor 3.2 an so on?

My Imacon generated files has no mention of it while other scans from NORITSU machine has NORITSU in EXIF.

Thank you for links, very useful.

Read about the 3F format in the batch scanning section of the documentation. You can also post questions at the imaconusers group on yahoo.

http://groups.yahoo.com/group/imaconusers/