Page 6 of 6 FirstFirst ... 456
Results 51 to 60 of 60

Thread: Epson 4990 vs v850

  1. #51

    Join Date
    Jul 2016
    Posts
    2,223

    Re: Epson 4990 vs v850

    Quote Originally Posted by interneg View Post
    My own experience is that making an adjusted .tiff from the scanner (especially in terms of setting curves before the scan) seems to offer more flexibility
    Possibly the x5 is working internally with more than 16 bits per channel. Depending on how the 4.9D range is placed in the 16 bits it is possible that the effect you are guessing can happen, if the curves are applied to the internal (24bit perhaps) value before converting to 16 bits.

    Nominal 4.9D is not a joke...

  2. #52

    Join Date
    May 2017
    Posts
    131

    Re: Epson 4990 vs v850

    Quote Originally Posted by interneg View Post
    My own experience is that making an adjusted .tiff from the scanner (especially in terms of setting curves before the scan) seems to offer more flexibility than working with a 3F (which by all accounts is simply a notionally straight out of scanner unadjusted, uninverted .tiff openable only in Flexcolor).
    I can understand that adjusting an "untouched" tif from the scanner, with say photoshop would be different from working with a 3F which from my understanding is a "RAW" file from the scanner, kept in a modified and unique tif file format, created by IMACON, as the processing pipeline would in fact be different, and the results would vary. I spent some time studying the manual and I could not find any evidence of additional hardware controls (beyond exposure) that change the way the 3F files are created. For example there is no Log amp that needs adjusting.

    I definitely intend to do some scans with an Imacon in the future (hence the reading of the manual), scanning them to 3F and using the Flexcolor software.

  3. #53

    Join Date
    Jul 2016
    Posts
    2,223

    Re: Epson 4990 vs v850

    Quote Originally Posted by interneg View Post
    In two words: optical aberrations. It's perfectly possible to design a very cheap optical system with surprisingly good high contrast resolution and much worse performance elsewhere, loaded with spherical aberration that kills fine, more normal contrast details. That's what the Epson does, much like the lenses in disposable cameras. It's like the difference between a pre-aspherical 35mm Summilux at f1.4 & an Apo-Sironar (choose your flavour) at f22. One could be theoretically higher resolving (diffraction etc) but one will be clearly far, far more perceptibly 'sharp' owing to lack of spherical aberration. The sheer number of glass surfaces in the Epson between film & lens will also drastically increase the amount of halation present, over and above any potential performance of the lens/ optical system. The high price of high-end CCD scanners had and has a great deal to do with a flatbed optical system that's free to a great extent of halation & chromatic aberration, using highly corrected optical systems to do so.

    No amount of fiddling in Photoshop will change that - unlike distortion or chromatic aberration correction. Do you now understand why an aberration free 2048ppi is vastly better than a grossly aberrated 2300ppi?

    Interneg, IMHO you are right describing that effect, and the Linos/Rodenstock inside the x5 is an important factor.

    I guess I know what the x5 has inside because I use the same family of lenses for machine vision and, by chance, also for linear cameras/sensors.

    The Linos product range for Machine Vision is a popular choice for linear cameras:

    Click image for larger version. 

Name:	0001297_rodagon-wa-4060.jpeg 
Views:	6 
Size:	21.2 KB 
ID:	178941
    https://www.infaimon.com/producto/rodagon-wa-4-0-60/

    Yes, you were right in principle, but you have to consider that V850 plays with some advantage, it has 2 cheap lenses but working each at a fixed distance, while the x5 lens has to enlarge more or less than in the optimal point, by changing sensor to film distance. With a so close subject this has an impact....

    I guess that the lens in the x5 was selected to perform optimally for MF, but also working acceptably at 1/2 and at x2 that magnification, for 35mm and for 4x5".

    Yes, the retail price (for me) of the Linos is the same cost than a V800... but the lens in the EPSON still has contrast extintion by some 3200 dpi. Well, I've destroyed an EPSON while trying to replace the plastic lens with an spare Linos I had... this would had been a nice hacking !

    It is true that the effect you described it happens to some extend, but in a limited way. At the end because that (IMHO) the epson scans benefit from some digital sharpening, remarkably closing the gap, as the Petapixel test explains, and it also can be checked from the large collaborative test, the sharpened sample I posted proves it...

  4. #54

    Join Date
    Dec 2013
    Location
    Nashville
    Posts
    386

    Re: Epson 4990 vs v850

    Quote Originally Posted by Pere Casals View Post
    At the end because that (IMHO) the epson scans benefit from some digital sharpening, remarkably closing the gap, as the Petapixel test explains, and it also can be checked from the large collaborative test, the sharpened sample I posted proves it...
    You keep quoting the PetaPixel article in support of your position that the V850 is the equivalent off the X5. Here is what they said:

    "The print is quite small at 25x25cm, and it’s questionable as to whether the Flextight scan was necessary here. I’ve had prints made from my v700 scans in the past up to 50x50cm and my printer has told me that the scans are good enough for this with a little sharpening, dependent on the quality of the negative, but going any larger requires a better scan as interpolating up requires the detail to be there first. The other prints I had done at the same time as this one are much larger than 25x25cm, so having them scanned with the Flextight was beneficial."

    The author was scanning medium format. A 25x25cm print is 4x. A 50x50cm print is 8x. For prints larger than 8x, they are saying a V850 is inadequate. I think they are being generous. I wasn't happy with 6x enlargements. Why you think 30x enlargements are adequate is beyond me. Like I said, smaller enlargements cover a multitude of sins.

    Quote Originally Posted by Pere Casals View Post
    To me it has little sense to make a 2m print and viewing the image with the nose on it. A 2m print has to be viewed at least from 1m, and at that distance 2lp/mm in the print are seen as perfectly sharp.
    This is an approach of adequacy, not quality. It makes sense for billboards and bus stop ads, but is antithetical to fine art prints. It is equivalent to recommending cheap enlarging lenses because at 1m no one will be able to tell the difference. Most printers have higher standards than adequacy.
    Last edited by faberryman; 6-Jun-2018 at 11:03.

  5. #55

    Join Date
    Jul 2016
    Posts
    2,223

    Re: Epson 4990 vs v850

    Quote Originally Posted by faberryman View Post
    You keep quoting the PetaPixel article in support of your position that the V850 is the equivalent off the X5.
    Faberryman,

    I've never said that a V850 is equivalent to an X5, I know exactly what each device does.

    What I say is that in a lot of conditions the result is really close, if densities are moderate and scanning sheets.

    Look, this crop is displayed as if it was was from a 2m high print from a 6x6cm MF, and the diference is what you see:



    Yes, perhaps the x5 is slightly better... but if it was a 4x5 negative it would be equal because the x5 has the half the resolving power if doubling the format, while the V850 holds the same.


    Quote Originally Posted by faberryman View Post
    This is an approach of adequacy, not quality. It makes sense for billboards and bus stop ads, but is antithetical to fine art prints.
    IMHO fine art is not directly linked to resolving power in the print: "Fine art photography is photography created in accordance with the vision of the artist as photographer." I like that definition.

    https://en.wikipedia.org/wiki/Fine-art_photography.

    One of the best AA shots was made with a crappy Adon (and he invented Zone system that day), and fine art also includes soft focus lenses. Sally Mann sometimes makes the finest Art with lenses that have a crack in the middle.

    But going to math... not many 4x5 shots are resulting in true 40 lp/mm detail in the negative, in practice most are way under that. A 4x5 shot enlarged to 2 m is x16, so 40/16 delivers a maximum 2.5 Lp/mm in the print. I was speaking of 2 Lp/mm and you were pointing that this was not quality in a 2m print. Well, it's the practical technical limit of a good 4x5" LF shot.

    What I say is that usually we don't have detail in a LF negative that requires more than 2500 dpi, and in those conditions a drum sporting 6000 dpi is like a Ferrari in a traffic jam, with the V850 obtaining a perfect result if a proficient Ps edition is performed, speaking for example of BW sheets with moderate densities.


    PD: note that with V850 to obtain 2400 effective dpi we need to scan at 4800 and then (optionally) downsampling, and using moderate sharpening to obtain a nice look.

    A pro device like the x5 delivers straight a good result, without having to deal with 4x bigger files than with the Epson.

  6. #56
    Guilherme Maranhão coisasdavida's Avatar
    Join Date
    Apr 2012
    Location
    São Paulo, Brazil
    Posts
    337

    Re: Epson 4990 vs v850

    Quote Originally Posted by Sal Santamaura View Post
    I've waited until the V850 warranty expired to open it up.
    Sal, when I opened the V700 I felt the part that held the glass in place was so flexible that the glass could move up and down depending on the weight applied to it. Did you have the same experience?

  7. #57

    Join Date
    Nov 1999
    Location
    San Clemente, California
    Posts
    3,236

    Re: Epson 4990 vs v850

    Quote Originally Posted by coisasdavida View Post
    Sal, when I opened the V700 I felt the part that held the glass in place was so flexible that the glass could move up and down depending on the weight applied to it. Did you have the same experience?
    No, the metal tabs that hold the bottom glass in place seemed relatively rigid, but that's based on a quick first look. I haven't gone back in to complete the anti-static work. Also, my only use of the V850 has been with larger sheets right on the glass, not using a film holder which might put more down force on the glass.

  8. #58

    Re: Epson 4990 vs v850

    I got my v850 last year and have no complaints. The quality of the scans is quite impressive.

  9. #59

  10. #60

    Join Date
    Jul 2016
    Posts
    2,223

    Re: Epson 4990 vs v850

    This is an interesting article about the plustek 120, but it should be added that the epson improves a lot with multi-exposure feature when scanning Velvia deep shadows, and that in the same way the P120 improves when nailing focus also the v750 improves when focus is assured, specially if film is curled. Of course the P120 resolves a lot more, this is specially important if scanning from roll film that has sharp shots .

Similar Threads

  1. First scans with Epson V850
    By Steven Ruttenberg in forum Digital Processing
    Replies: 54
    Last Post: 26-Mar-2018, 09:09
  2. Epson V850: better optics, *really*?
    By sharding in forum Digital Hardware
    Replies: 27
    Last Post: 15-Aug-2017, 12:54
  3. Epson V850-Epson V800, what is the next step up.
    By Smorton in forum Digital Hardware
    Replies: 21
    Last Post: 1-Jul-2016, 10:31
  4. Opinions/Experience thus far on the Epson V850?
    By Daniel Stone in forum Digital Hardware
    Replies: 1
    Last Post: 13-May-2015, 16:03
  5. Epson V800 & V850. thoughts?
    By yuexiachou29 in forum Digital Hardware
    Replies: 10
    Last Post: 28-Mar-2015, 11:47

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •