Should I Drum Scan, X1 Flextight Scan, or use the Epson V850 w/Aztek Wet Mount Kit?

[Pere Casals]

Is there is a simple scanner PPI/pixel resolution calculation? I'm always confused about that. I.E. When someone asks for a 2000PPI scan what pixel resolution are you targeting.

First, we have hardware ppi and effective ppi. 2000ppi with a perfect lens outresolving the sensor may deliver 1800 effective ppi, if the lens limits effectively performance then effective ppi is lower.

Say you have 2000 effective ppi (pixels per inch) on the sensor, multiply it by the number of inches of the sensor and you have the total pixels. FF is 1" x 1.5" approx, so image resolution is 2000*1.5 wide and 2000*1 high, so 3000x2000 = 6,000,000pixels effective. 6 MPix


If efective ppi are measured on film, then use the inches of the film instead the inches of the sensor, for a 4x5" sheet:

2000x4 x 2000x5 = 8,000x10,000 = 80 MPix


For example a Hasselblad scans at 2000ppi but delivers 1800ppi effective on film in the horizontal direction and 1600 in the vertical direction for 4x5".

Total pixels will be 80MPix as it was calculated.

Effective pixels will be 1800x4 x 1600x5 = 57.6MPix effective.

The Hasselblad scans 4x5" at hardware 2000ppi because it has a 8,000 pixels sensor, that distributed in a 4" wide sheet are 8000pix/4" = 2000 ppi.

[grat]

There's a philosophy in computer science that's roughly summed up as "GIGO". Garbage in, Garbage out. Or perhaps, using the laws of thermodynamics, entropy always increases. Or the Las Vegas rules of Thermodynamics: You can't win, you can't break even, and you can't quit the game.

Applied to photography, you're never going to produce a more detailed image scanning a negative than the original negative**.

How many of these 4x5 or 8x10 negatives are being produced by lenses with anywhere near the MTF of the systems being used to image them at ultra-high resolution? Personally, I'm a novice at LF photography, so I have inexpensive lenses-- mostly single-coated Fujinons, with my best lens being a Schneider Symmar-S.

At 4x5, what's the realistic level of detail I should expect to find in my negatives?

My optics knowledge is pretty rudimentary (concepts, I know, math, not so much), and I know there's not going to be an exact translation between analog and digital.

** although modern machine-learning algorithms can make a really good effort at it.

[Sasquatchian]

Certainly anyone who shoots large format at smaller apertures - f/22 - f/64 and beyond are leaving a lot on the table resolution wise, but that's what a lot of people did throughout the years and still do today. For small to moderate print sizes none of this really matters but if you're into making very large prints, then you will see the difference.

From my personal experience, even the 8000 dpi Howtek drum scanner leaves a tiny bit of resolution on the table in an extremely sharp Velvia transparency, but scanning that at 8000 ppi even with its slight optical loss is still way better than any projected optical print, as the enlarging lenses simply fall apart especially in the corners and edges when you're at 40X enlargements, and that's further made worse when technicians choose speed of quality by exposing those large prints with the lens wide open. There is no thing as perfection here but there ARE methods that are better than others.

[Chester McCheeserton]

I could scan some HP5+ at that resolution. Are you thinking 4x5? I actually think I only have some 8x10 HP5 on hand but my camera is in the shop... I have a bunch of medium format HP5 however and was planning to do ISO/dev time tests with it.

Is there is a simple scanner PPI/pixel resolution calculation? I'm always confused about that. I.E. When someone asks for a 2000PPI scan what pixel resolution are you targeting.

not sure what exactly you mean by "pixel resolution" and I'm sure someone can jump in and deliver a sermon on the difference between dpi and ppi but basically someone with a 4x5 inch negative asking for a 2000 ppi scan means that after opening the scan in photoshop and going to image/image size the file dimensions are 4 by 5 inches with a resolution of 2000 ppi.

Or depending on whether it's full frame or not, approx 10,0000 pixels on the long side.

[Chester McCheeserton]

Certainly anyone who shoots large format at smaller apertures - f/22 - f/64 and beyond are leaving a lot on the table resolution wise, but that's what a lot of people did throughout the years and still do today. For small to moderate print sizes none of this really matters but if you're into making very large prints, then you will see the difference.

From my personal experience, even the 8000 dpi Howtek drum scanner leaves a tiny bit of resolution on the table in an extremely sharp Velvia transparency, but scanning that at 8000 ppi even with its slight optical loss is still way better than any projected optical print, as the enlarging lenses simply fall apart especially in the corners and edges when you're at 40X enlargements....

The proper name for that tiny bit of resolution is Aura, what Walter Benjamin called 'a peculiar web of space and time'....hahaha..

[Sasquatchian]

I'm not really inclined to spend a grand right now to see how Epson's scanners have improved since I last owned own a quarter century ago but I might have to just to see. What I think might be happening is that our friend here has never actually seen anything better, and certainly the drum scanning examples he keeps referring to are done with a scanner clearly not in optimal scanning condition. I'll check and see how my little ol' etrade portfolio is producing right now and maybe I'll go for one. I can always use it for documents, but a grand is also a new microphone too.

[Pere Casals]

I'm not really inclined to spend a grand right now to see how Epson's scanners have improved since I last owned own a quarter century ago but I might have to just to see.

The Epsons made a leap forward 14 years ago, they have not improved since 2006, today they manufacture exactly the same than then, with two improvements: the convenient LED illumination that has no heating delay and it's stable requiring no calibrations over time... and the ANR glass holders with adjustable height, this addresses the film curling that otherwise could lead to very flawed scans.

The Epson is not a Pro machine, it is in the Prosumer segment, clearly not made for those proffesionally scanning all day long, but ideal to have it at home. For a top notch result the image requires ensuring film flatness/focus and a careful edition that not every consumer user is able, anyway this is way less work than wet mounting for a drum.

In that test made by Pali the V700 excells because the scanning/workflow was proficient, with the Epson one has many opportunities to make a botched job, starting by not addressing curling/focus, then one has to scan at oversampled top dpi-16 and optimizing sharpening before downsizing to the edition size and using the right downsizing algorithm, this is not as necessary in a pro scanner.

Thanks to "modern" computing power those oversampled operations are practical.

Also the Epson requires the Multi-Exposure effort for dense Velvia... But it has the iSRD feature saving a lot of manpower with color film.

For color negative film (MF and up) you won't find a better result from a better scanner, as that test showed to the surprise of many, Pali included. It is true that BW grain structure (for beyond x10 prints) is not as detailed as with superior scanners, but this is usually not a concern in LF...

With scanning YMMV, what is for sure is that the Epson is a quite powerful machine for LF, in the right hands. Some won't be able to get great results.

I'm not really inclined to spend a grand right now to see

If you want, I'll give you an address to send one or several negatives and I'll V850 scan it for you, then you may compare it for free.

Sadly in many places the V800 price nearly doubled in the last months... but I guess that price may return to it's "normal" level in the post-covid.

Right now the V850 can be found in Amazon-Spain for 660€ + VAT , the V800 for 500€ +VAT

[grat]

I'm not really inclined to spend a grand right now to see how Epson's scanners have improved since I last owned own a quarter century ago but I might have to just to see. What I think might be happening is that our friend here has never actually seen anything better, and certainly the drum scanning examples he keeps referring to are done with a scanner clearly not in optimal scanning condition. I'll check and see how my little ol' etrade portfolio is producing right now and maybe I'll go for one. I can always use it for documents, but a grand is also a new microphone too.

Alternatively, you could head over to YouTube, and watch a video by a photographer named Nick Carver. He took two 6x17 negatives (one negative, one transparency), had them professionally drum scanned, scanned them in a wet mount setup with his Epson, and with his Canon 6D, then had them printed at large size to do comparisons. He felt that pixel peeping, while entertaining, isn't really the goal-- something that can be hung on the wall and displayed is.

For those not wanting to watch the video, the summary was that the best quality was the professional drum scan, followed closely by the DSLR, and then the Epson-- But in terms of normal viewing of the print, it just didn't matter. The Epson workflow was far preferred, because he had direct control over the color (in his opinion, the Epson did the best job of matching the color as shot), and the DSLR, while it produced high quality images, was incredibly frustrating to get the stitching just right, and the color balance kept coming out "Canon", even when he used Fuji Velvia. He also admitted a lack of practice and knowledge on the stitching and color balance, but felt it was still an unholy nightmare compared with using the Epson and SilverFast. Having it done professionally was incredibly easy (because it wasn't his effort, only his money), but there's a lack of control on the final product.

The video is here: https://www.youtube.com/watch?v=Q9d8BukUgzI

[sperdynamite]

I find that video very annoying because you can see from the start he was inclined to write off camera scanning. Then his technique for making the scan was atrocious. No masking, sitting right on the light source, no copy stand, and using a crappy Canon sensor. When I commented that his technique could be improved in a number of ways he was belligerent about it of course.

[Pere Casals]

Alternatively, you could head over to YouTube, and watch a video by a photographer named Nick Carver. He took two 6x17 negatives (one negative, one transparency), had them professionally drum scanned, scanned them in a wet mount setup with his Epson...

Well, it is an interesting video and his points of view are quite useful in part, at least for those not wanting to investing an effort to obtain the best yield from each way.

Anyway in scanning YMMV and with any system one may get better or worse results depending on the effort we make in mastering that system.

Performance/convenience also depends on format.

Regarding color, he does not consider that a Drum or DSLR scanner will match the Epson CN conversion with the right calibrations / profiles. An he also does not mention that the Drum colors of slides usually are optmized by the scanner service people after scanning, this can also be made with the DSLR and Epson images. And also he does not says how he scans slides with the Epson, which requires special attention in the oversampling management anf for high densities.

No masking, sitting right on the light source, no copy stand, and using a crappy Canon sensor. When I commented that his technique could be improved in a number of ways he was belligerent about it of course.

Yes, but he is stitching, so sensor is not to be a factor. Even with shifting with one shot scan you have the lens optic limitation, it would be a surprise if the Sigma ART is to deliver more than 30MPix effective, if stitching you also overcome the limitation from the optics.

...but I agree that his poor evaluation of the DSLR way is very influenced by a lack of effort in its optimization.

Something is true, for the DSLR way one needs to control dust very well.