Scanning Resolution Question

[Pere Casals]

It's going to look rubbish alongside a print from the same negative scanned on a better scanner. Multiple people have gone over this multiple times with you. Either get a drum scan & see for yourself or stop trying to pretend the Epson is something it isn't. It's OK for basic proof scans, but for top quality negative scans that do justice to the negatives, you need something much better. The quality of the resolution is what matters, not the supposed quantity.

Interneg... the quality of the resolution is LP/mm


Tell me how 30 Lp/mm can be better than 40 Lp/mm because that 30 can be of better quality than 40...

Resolution Quality? in what terms? DR? Acutance? Color accuracy? what numbers?


Look, I've been comparing a lot of drum scans (and flextight scans) to v750 scans, and I saw it is very clear when drum matters a lot and when not at all. Also I've been technically evaluating what in hardware (or in the driver) digital image enhancing resources are used or not, and how that can be adressed in post process. One has to know what a human eye can see or not at all.

See here how and edited V750 scan will look like one from a drum. You can take the images from the collaborative LF test and try on your own...




IMHO, most difference is in the man that scans and edits with PS, with the exception of velvia very deep shadows, where a drum rocks, and all (good) flatbeds have same amount of problems with scanning stray light (depending on scene, a very dark overall slide has lower stray light for a flatbed).




Also you will know that real photographic conditions are not lab conditions. If camera has a shake of 0.03mm you won't have 40Lp/mm, Camera planes are not exactly aligned, there is tolerated DOF... etc, etc, etc...

So it is difficult to find negatives that will need extreme scanner performance to shine. It is true that expensive scanners cook internally more the image by default, but you always can do that with Photoshop.

At the end what counts is photographer.

[interneg]

the quality of the resolution is LP/mm


You cannot tell USAF guys that their 1951 chart has a flaw !!! ...because 30 Lp/mm can be better than 40 Lp/mm because that 30 can be of better quality than 40...

Resolution Quality? in what terms? DR? Acutance? Color accuracy? what numbers?

MTF tests will tell far more than a single target designed to be imaged at high contrast. Edge definition, accutance, aberrations all have their own tests too. Accutance is vitally important to the appearance of sharpness & the Epson has very low accutance.

I've been comparing a lot of drum scans (and flextight scans) to v750 scans, and I saw it is very clear when drum matters a lot and when not at all. Also I've been technically evaluating what in hardware (or in the driver) digital image enhancing resources are used or not, and how that can be adressed in post process.

See here how and edited V750 scan will look like one from a drum. You can take the images from the collaborative LF test and try on your own...

It's pretty obvious that the Epson operates nowhere near the performance of any of the high end scanners. That you omitted to compare it with the Heidelberg Tango in your selection is very telling.

That test has its own small flaws - ie using interpolation on the Imacons instead of looking at everything at their actual resolutions & no real indication of maintenance/ adjustment on the scanners. But even the up-scaled Hasselblad/ Imacon scan blows away the Epson for sharp resolution & that's supposed to be lower in resolving power than the Epson. The colour fringing on the Epson is horrific.

Your touchingly naive belief in the USM as a cure all is hilarious. It might enhance apparent 'sharpness' but it also increases grain and other noise too. A truly crisp, in focus, non aberrated scan may not even need sharpened at all.

Believing you can magically 'fix it in post' is just that - magical thinking. If the data isn't there, you can't make it appear unless you indulge in CGI. Instead of 'comparing' online resources and producing voluminous pseudotheory, how about getting a drum scan made of that negative? Or are you afraid that it'll tell the truth about the Epson?

At the end what counts is photographer.

Most photographers operating at the top of their game are incredibly fussy about the qualities & handling of colour. High end scanners enable you get access to far more of the relevant information than an Epson. The End.

[Pere Casals]

MTF tests will tell far more than a single target designed to be imaged at high contrast. Edge definition, accutance, aberrations all have their own tests too. Accutance is vitally important to the appearance of sharpness & the Epson has very low accutance.

How much acutance V750 vs IQ2 ??? None, zero, nothing: the same in practice

Better USAF Lp/mm is always from better MTF graph.

It's pretty obvious that the Epson operates nowhere near the performance of any of the high end scanners. That you omitted to compare it with the Heidelberg Tango in your selection is very telling.

Go to LFPF Collaborative scan test and instead Howtek take Tango images, cook in PS to the optimum and compare. Also compare to other flatbeds.

I don't doubt drums have better performance, that sometimes help, sometimes not at all. What I say is that V750 compare very well with other expensive flatbeds, and even is near from certain drums in certain conditions, not always of course.

Instead of 'comparing' online resources and producing voluminous pseudotheory, how about getting a drum scan made of that negative?

Sorry, but you are not evaluating well the thing.

"LFPF Collaborative scan test" is not a lab MTF test, but a practical one with practical photographic results, and it is a neutral test.

So you have in front of your nose very enlarged crops from matching 45 negatives (made at the same time, and sent to very skilled people), scanned with most prominent scanners.

If you can't judge that in practical photographic terms it is not worth to continue the discussion, so the end.

My recommendation is that you take "LFPF Collaborative scan test" crops and try to make it match in PS, you'll have the opportunity to abandon silly prejudices that are around, and you'll learn what matters and what not in a digital image.

(In the LFPF Collaborative some shadow detail of the red box it is much worse in the V750, I guess this is because ME was not used)

[interneg]

I don't doubt drums have better performance, that sometimes help, sometimes not at all. What I say is that V750 compare very well with other expensive flatbeds, and even is near from certain drums in certain conditions, not always of course.

I read you all right, you are desperate to elevate the V750 and are producing voluminous clouds of obfuscation and disinformation. Unlike you, I know how higher end scanners behave compared to the Epson because I have used them. You are increasingly becoming a textbook illustration of Dunning-Kruger.

[bob carnie]

I read you all right, you are desperate to elevate the V750 and are producing voluminous clouds of obfuscation and disinformation. Unlike you, I know how higher end scanners behave compared to the Epson because I have used them. You are increasingly becoming a textbook illustration of Dunning-Kruger.

I had to look that one up.... I think I have found my nameskeep.


Pere - you are becoming a PIA to say the least

[Corran]

+1 to everything interneg is saying. This is far afield from the original question. With regard to the Epson Vxxx scanners what I have observed is that the highest available resolution is achieved by scanning at 4800 or possibly 6400 and then downsampling to 2400 DPI. My observation with most consumer scanners is that from the point of "maximum resolution" the scan should be further reduced another 50% to look its best. This brings the Epson to about 1200 DPI which gives roughly a 4x enlargement ratio, or about 16x20 max from 4x5, which matches what most users have reported. I used an Epson V700 for a while before buying various other scanners. Actually I had a sample size of 4 Epsons at the local college and they all performed about the same. Finding the right height of the holders is essential for getting the best usable resolution.

[alanbutler57]

I don't know about detail comparisons etc. But I usually scan 4x5 negatives at 3,000 -3200 dpi on the Epson V750.

Then, I reduce the image size to 10,000 by 8,000 pixels in PS using "Sharper, Best of Reduction" setting. This does a very good job of sharpening the image without halos etc. I usually then apply and edge mask and hit with a healthy dose of unsharp mask.

The resulting image is big enough for a good sized print if I choose to make one and the bigger files look to take higher levels of unsharp masking better to my eye. Of course it takes a looooong time to scan.

[bob carnie]

Today I am printing files from the new Phase One XF - the 100mb beauty.

44 x 60 inch prints on Silk Bayrta paper. I can say that this is the first time since making large murals on Cibachrome from 8 x10 trans that the image quality I am seeing is equally impressive.

There is a significant difference at this magnification from the clients old camera NikonD 800 to this new camera.

I think with these new systems we are reaching very high quality output and once this quality is out there the bar has been set.

[Corran]

Bob, the native pixel measurements on the XF shows a bit less than 200 DPI for that size print. I assume you are upsampling and processing appropriately for that size print? As I've said before, digital files can be uprezzed pretty significantly and still make very sharp prints. I don't doubt for a second you have more than enough resolution for that size despite the "apparent" lack of pixels at native resolution. Many have argued when I've said I could easily print my D800 files to 36x24 and hey guess what that is the exact same roughly 200 DPI situation for the native pixel sizes.

[bob carnie]

Bob, the native pixel measurements on the XF shows a bit less than 200 DPI for that size print. I assume you are upsampling and processing appropriately for that size print? As I've said before, digital files can be uprezzed pretty significantly and still make very sharp prints. I don't doubt for a second you have more than enough resolution for that size despite the "apparent" lack of pixels at native resolution. Many have argued when I've said I could easily print my D800 files to 36x24 and hey guess what that is the exact same roughly 200 DPI situation for the native pixel sizes.

Hi Corran - the files were prepared in Capture One by my client to the size I printed.... my observations is that from a medium format anything ... this new device reminds me of the good old days of 8 x 10 trans direct print to super size Cibachrome.
I have made 4ft x 72 inch cibas in my past life.


I have been waiting a long time with digital capture to see this , my point is I think the quality issue is for me at least put to bed between 8 x10 trans and digital capture... Looking at these large prints say it all.