I haven't. Someone else may have. Specifically, Silverfast gave me that conversion. They've been doing this awhile, so I'm not prepared to argue with their methodology.
Have you not made an error in calculating, surely 125 lppm = 125x2x 25.4 =6350 ppi?
This deserves a long explanation:
You are right, I was mixing concepts of the X5 with the X1 that cannot scan 24mm width, so we just need to upgrade those numbers by a 6900/6300 factor, this is a 9% higher values. My mistake... please understand that I made that rating several years ago and I missed a 9% capability
So the right numbers are: 1725dpi at extintion for 4x5", which is total contrast extintion at poor 34.5cy/mm, so MTF 50% is obtained at 17.25cy/mm instead 15.5. Well, not nice for such an expensive scanner, quite good for 35mm but with a really limited capability for 4x5". At 1750dpi you have zero contrast !
No, it really doesn't-- at least, not in this discussion. I care not one whit about you and Lachlan's incessant feud about the v700 vs. the X1-- you've both occupied an extremist position bordering on religious fanaticism, and neither of you is going to budge, so why keep trying?
I've said it before-- given the price differential, the X1 had better deliver superior results, but that's irrelevant to the discussion of how to determine the best resolution to scan a particular negative.
how to determine the best resolution to scan a particular negative.
I've said it before-- given the price differential, the X1 had better deliver superior results, but that's irrelevant to the discussion of how to determine the best resolution to scan a particular negative.
Again, you're guessing. The mechanism of the X5/ 949 allows 25mm - 99.6mm (officially 100mm) transmissive scanning ....
The V850 comes with two sets of adjustable holders with ANR glass to keep the negatives flat. That speeds up the scanning process. You can be setting up the second holder while the first holder is being scanned. I believe the V850 has ICC slide for better color handling, but you may need the more advanced Silverfast. (I use Epsonscan). Epson claims that the lens on the V850 is better than the V700/V750. That accounts for the faster speed, so they say.You can review the comparison at https://www.filmscanner.info/en/EpsonPerfectionV800Photo.html
Effectively, the V800 is equal to the V850 and achieves slightly higher res then the V700. The V800 has better holders and faster scan times too.
Why take a chance with 8 bits when 16 bits is available? There's no downside with 16 bits other than more storage space. On the upside you have more to play with.for example you have the sky, or water bodies, or buildings... if you don't manipulate much the curve you won't have problems in 8 bits, but there is no doubt that high contrast scenes needding a deep edition require 16bits
Also... sharpening algorithms are to work much worse in the deep shadows, if deep shadows are enconded 1 to 16 levels, for example, operations are truncated delivering way less precision, if later you expand those shadows.
A proficient edition is in 16bits, still 8bits can be totally acceptable in many situations, this is also true.
Why take a chance with 8 bits when 16 bits is available? There's no downside with 16 bits other than more storage space. On the upside you have more to play with.
Scan times were halved when the Coolscan 4000 was updated to the 5000. The scan times were also halved between the first version Minolta 5400 first to the second version. In both cases, one of the major changes was changing the light source from cold cathode to LED. I would guess that since the scan times were also halved between V7XX and the V8XX that it must have also been because of the change from cold cathode to LED light source or at least significantly because of it.Epson claims that the lens on the V850 is better than the V700/V750. That accounts for the faster speed, so they say.
As someone who scans 7 days a week for clients I can tell you I spend NO time thinking about MTF charts.
To your point - at least as far as scanner resolution is concerned, all is already known. However, there are always new people who needs their film scanned and as always it starts at how much would it cost in time and money. It's their time and money - and their cherished images, so I can appreciate why they would find the best they can get.
But IMO we have several addtional factors. A critical factor is skills, results in the hybrid workflow are more related to skills than to the digital gear. A proficient scanning, a careful edition and a solid aesthetic criterion for the edition it is what it shines.
Many people having an Epson V700 don't know what that machine is able, because not having adjusted media height or ensured flatness, or not knowing how to make the refined sharpening Epson scans require in post, to obtain the best result while totally avoiding overshot.
Les, see the table at the bottom, and you'll see that that test is not that arbitrary, but a good example of the reality.
Since many years ago RA-4 darkroom printing has been declared near extinct, almost nobody prints RA-4 optically. Priority has been scanning since the digital minilab era in the 1990s. What % of the RA-4 prints are optic? one in one million?
If you observe color negatives of the pre digital minilab era with a microscope, at (say) x400 you may see that the image structure (color clouds) changed compared to color negative film made in the digital minilab era.
See this table:
View attachment 253167
Reference: http://www.tmax100.com/photo/pdf/film.pdf
These are results from contact copies. Amazingly the 40 years old VR100 (The kodak product that introduced T-Grain in around 1980) has the best rating of the color films, but it had some grain and more color noise in the scanning. If you make clouds larger then clouds from a color layer overlap better with clouds in the other layers, lowering color noise in the discretization.
There always had been a trade between size of color clouds vs granularity, a film that scans easy may require larger color clouds, at the end lost sharpness can be compensated with a wise digital sharpening. Of course a detailed analysis should consider what average cloud size we have for each density in each layer, measured in the reticle of a microscope... but to compare it's enough to inspect at x400 how gray subjects with same density (concrete buildings, for example) have the clouds overlaping less or more.
In the other hand that contact test suggests a resolution value in ppi, this is 3300 to 3700 for the old Portra variants, but those are tests from contact copies, those figures have to be lowered for practical shooting conditions, the same document calculates the actual ppi once the lens performance has degradated the image, note that Portra 160 was peaking 2450 with a very good 140 lp/mm lens:
View attachment 253169
This fully explains why an Epson V700 is able to get all IQ Portra 160 is able to record, as it is able to resolve 2900dpi effective in the Hor axis and 2300 in the vertical one.
I guess this table is a precise answer to what OP was asking.
Then you might also be interested in articles posted at https://clarkvision.com/articles/index.html
A good reference between film and digital with a lot of studies related to resolution.
Are you still talking about scanner resolution here . . .
There are several things that are highly problematic with those articles.
At the rates you charge, I can see why you have no time. You are too cheap! I've done a few scans for pay and there is no way I would do it for that.
To your point - at least as far as scanner resolution is concerned, all is already known. However, there are always new people who needs their film scanned and as always it starts at how much would it cost in time and money. It's their time and money - and their cherished images, so I can appreciate why they would find the best they can get.
If film services are so expensive that amateurs and artists cannot afford to use it, then what is the point?
Are you still talking about scanner resolution here . . .
Well, that was off-topic cheap philosophy, I've to admit it
We certainly get what we pay specially when it comes to system wide resolution . . .
Here is a another good example of how much resolution it is possible to get out of film, and this not even with optimal equipment.
IE “only” a 5400 dpi scanner and less than optimal film to show resolution:
View attachment 253272 View attachment 253273
http://www.rokkorfiles.com/7SII.htm
Notice how you can see the individual minute marks on the clock face!
This is far, far from the 2600dpi claimed by 138S and authors of the articles as the practical limit for colour film.
So, as members of this thread, what can we agree on? Where are the points of disagreement? Why? Is there any non-emotional way to resolve these disagreements?
Phil Burton
Because the thread is about Satan's spawn - scanning!!!So, as members of this thread, what can we agree on? Where are the points of disagreement? Why? Is there any non-emotional way to resolve these disagreements?
Phil Burton
A simple test to check the effective level of detail of an image file is to downsize it (e.g. in Photoshop) to see at which resolution the image loses image content details. You can download that crop, load it into Photoshop, set the resolution to 5400 ppi (without resizing) and then resize to lower resolutions. Resizing the scaled down image back to the original resolution and adding appropriate sharpness will help seeing which details can be retained and which are lost in the process.Helge, this crop is made at 5300dpi, yes, but the 100% crop is quite blurred and probably you have no more than the half (2600dpi) effective.
I'm totally confident that the Epson would be able to catch all IQ that this negative has if scanning 4800 or 6400 to also yield around 2600 effective.
A simple test to check the effective level of detail of an image file is to downsize it (e.g. in Photoshop) to see at which resolution the image loses image content details. You can download that crop, load it into Photoshop, set the resolution to 5300 ppi (without resizing) and then resize to lower resolutions. Resizing the scaled down image back to the original resolution and adding appropriate sharpness will help seeing which details can be retained and which are lost in the process.
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