Bruce Watson
I'll be the first to say that understanding some of this is difficult. For one thing, we all talk about scans as if we are scanning a pixel - or a bit of the image. However, they are just reads, as in a value from 1-255 in lightness darkness for three different channels of color separated light.
I do understand the stated resolution issue. It shows up clearly in the Tango, which can do 11,000 spi, yet only resolve 4000. However, you have often said that your assessment of the real resolution of the 750, for an example, was around 2000 or so (don't remember the exact #). I understand that this is quite different from pixel count, and is not the stated resolution of 5300 or whatever... However, if it is true that it is at a true optical of 2000, the 2400 you stated as the max one could get from a 4x5 would be very close.
What am I missing?
Lenny
EigerStudios
Museum Quality Drum Scanning and Printing
I would be happy to show you such a thing. I have 32x40 images on my wall, come on by....
I scan 8x10's at 2666 and 4x5's at 4,000. The latter is 16,000 pixels by 20,000 pixels, or 320 mpixels. It think its pretty good, much better than 50 lpm would suggest. The scanner is rated at just under 8,000 ppi optical...
I don't know if that adds anything or not...
Lenny
EigerStudios
Museum Quality Drum Scanning and Printing
Lenny,
First, I think you are missing a lot .
As for the Tango resolution, no way the Tango has real optical resolution of 11,000 spi. The aperture of the Tango suggests no more than about 2500 spi. Of course, we know that is not bad since for many years Tango scans of transparencies were considered state of the art.
Sandy
Bruce,
I think something is missing here. Maybe its just something I don't understand. The Tango got a 4094 optical dpi at scannerforum.com, numbers I tend to trust. I think there is more than meets the eye. I think it has to do with the optics required to support a 6-micron engine. The Tango likely has a 6 micron capability, but they chose not to allow the aperture to vary, probably a software issue, I'm guessing, but the optics are still there that support it. 13 is better for almost everything, and they let color negs go and got everything else. Probably all about money or time, whatever.
I don't think resolution is closely related to the aperture setting. For instance, when I scan at 4,000 dpi at 13 microns, by rights I should get a lousy optical rez. There are only just 2000 13 micron slices per inch, but I get a much higher optical rez when I scan at the 4000 - from what I see I get at least the full 4000. I get maybe a few percentage points less than if I set it to match the dpi and aperture. But it doesn't cut itself in half. I have high suspicions that the idea that you can only get 8,000 ppi optical by scanning at 3 microns is entirely incorrect. It may be a little better if you do, but the grain anti aliasing will kill you. I doubt they made this error - I mean why bother with a 3 micron capability if there was no film that had a RMS Granularity to match it. It has to be to support the engineering.
Just my 2 cents,
Lenny
EigerStudios
Museum Quality Drum Scanning and Printing
Sandy,
I stated right there in my post that the Tango can only resolve 4000, not the 11,000.
I am enjoying this conversation, we have a group of very intelligent people here, discussing some very technical issues. It's great. I'm doing my best to listen - and learn. I am happy to admit what I don't know - and wanted to give you an opportunity to fill me in on something - as I don't see it the way you do. Instead, you take the opportunity to take a shot at me and suggest that I don't know jack.
Don't mistake being willing to listen with not knowing anything. I've been studying this stuff for a very long time and I've made a lot of great scans. I run 2 12 color printers and make all my own profiles, do all the stuff many others do. I know a great deal about all of this. I think there are some key things missing - that we are all missing. I don't think anyone here, including myself, has a grasp of it all, not even a full grasp of how scanners work. Even the great Phil Lippincott, who designed a huge amount of the technology we are talking about had limits when I talked to him about practical application. There aren't great books on the subject, that I know of, and there is no long "scanner school" which there used to be.
And now, once again, instead of discussing the issues, I have to take the time to defend myself against personal attack. I have to stand up and tell people all my experience, that I know a lot etc, and it stinks. Last week, you told people to "diss me" if I spoke up about flatbeds or some such thing. We have a conversation and you agree to disagree professionally and then you pull this crap again. You might have noticed that I have not said anything disrespectful to you - I have always disagreed with respect. I think we ought to stick with the issues.
Lenny
EigerStudios
Museum Quality Drum Scanning and Printing
Lenny,
Excuse me, but you stated right here,
"I do understand the stated resolution issue. It shows up clearly in the Tango, which can do 11,000 spi, yet only resolve 4000."
Why would you say that the Tango can do 11,000 spi but only resolve 4000 and then complain because someone questions your language?
Get over your raw nerve. I have zero interst in attacking you personally and have not done so, and it is getting tedious having to explain to you otherwise.
Sandy King
Last edited by sanking; 17-Nov-2008 at 20:39.
Bookmarks