Scanner comparison: Epson V750 Pro added

[sanking]

Take a break and read how how high end scanners like the Cezanne Elite and Eversmart deal with this problem, i.e. distance between the CCD and the material being scanner. The Cezanne uses a tecnique called XY-Zoom, the Eversmart XY-stitching.

There is no religion here, just optical facts. If one uses a focusing lens, there must be a compensation for focus (and area of coverage) for distance between the CCD and the material being scanned. If one uses a non-focusing lens, there must be compromises for area covered and distance between the CCD and scanned material. Some scanners deal with this issue by mowing the lawn in strips and then stitching (Eversmart), others by zooming out and re-focusing (Cezanne Elite). The Epson V750 does not deal with the issue of all other than by offering two lens that scan at about the same distance from the CCD, but do not focus. Is that about right?



Sandy King

All the film mounts for the V750/V700 are aimed at 'above the glass' focus. Only the 8x10 'area guide' is intended for 'on the glass' focus. We have stock 4x5 film holders and the purpose of them is to scan 4x5 film with the 'hi res' lens 'above the glass'.

Logic has nothing to do with it.

There is religion mixed with science here.

[Ron Marshall]

I use my 4990 for 3x-4x enlargements, for which with most images it does a good job. When I plan to print larger I get a drumscan.

There is no mistaking a 4990 scan for a drumscan, either on screen or in a print.

[PenGun]

Take a break and read how how high end scanners like the Cezanne Elite and Eversmart deal with this problem, i.e. distance between the CCD and the material being scanner. The Cezanne uses a tecnique called XY-Zoom, the Eversmart XY-stitching.

There is no religion here, just optical facts. If one uses a focusing lens, there must be a compensation for focus (and area of coverage) for distance between the CCD and the material being scanned. If one uses a non-focusing lens, there must be compromises for area covered and distance between the CCD and scanned material. Some scanners deal with this issue by mowing the lawn in strips and then stitching (Eversmart), others by zooming out and re-focusing (Cezanne Elite). The Epson V750 does not deal with the issue of all other than by offering two lens that scan at about the same distance from the CCD, but do not focus. Is that about right?



Sandy King

No. They scan at different distances. One on the glass and the 'hi res' system above it. The film holders are all set for the above the glass focus which is the 'hi res' system.

The 8x10 'on the glass' scans are full width.

All the film holder scans are 5.7" wide which is enough for the 35mm holder to be 3 wide, the 120 to be 2 wide and the 4x5 is 1 wide above each other. I can see no evidence to support any of your suppositions. The 35mm test I use appears to be the same in the center or on either side.

You have made quite a few claims and do not have a V750/V700 and have assumed it is the same as your 4990. As I have pointed out I believe the 4990 is about the same as the 'low res' system used on the V750/V700.

Again. I have seen nothing wet mounted at the correct height using the 'hi res' system. I will get to it myself but probably not soon as I have so much to learn. I do know about where my 'hi res' system focuses but not too much more. The test scans on 35mm are much better than I thought they would be but as I pointed out I had to find the focus plane.

[PenGun]

Basically, the only logical reason for the two lenses that I can see is that one was meant to scan a smaller area of film at higher resolution.


Sandy

I'm slow tonight. Exactly. I have seen no tests of the "one was meant to scan a smaller area of film at higher resolution". Eh'.

Did you even test the 'hi res' system?

[PenGun]

Hi Pen Gun,

As for your comments, "you have made quite a few claims and do not have a V750/V700 and have assumed it is the same as your 4990". OK, you pretty much missed the launching. I have tested both the V700 and V750, in my environment. I just don't currently own one, primarily because on testing I did not find that either offered much of an improvement over the 4990.

Frankly, you can compare and test until hell freezes over, but it won't change the basic facts. End of message. End of exchange.



Regards,

Sandy King

I'm pretty sure you did not test the 'hi res' system as you seem to know very little about it. I will satisfy myself as to the facts with tests and the reason is to find out what the basic facts are.

They are not well revealed so far.

[sanking]

Thank you for placing things in perspective. I feel so simple and uninformed compared to a person like you with such vast knowledge and experience withi scanning equipment.

Sandy King

I'm pretty sure you did not test the 'hi res' system as you seem to know very little about it. I will satisfy myself as to the facts with tests and the reason is to find out what the basic facts are.

They are not well revealed so far.

[PenGun]

Thank you for placing things in perspective. I feel so simple and uninformed compared to a person like you.

Sandy King

Did you test the 'hi res' system?

[Paul Kierstead]

But, by any reasonable measure they are not even close to professional flatbeds and drums scans in performance.

Although I entirely agree with you on drum scans (though the Epson may give more then acceptable performance under certain conditions), I am not so sure about the professional flatbeds. Looking at the sample scans, they certainly did not knock my socks off like the drum scans, and might be debatable quality w.r.t. the Epson. I am not just talking about sharpness here, but more complete "feeling" of image quality I'll admit to not looking at all the samples, so may not have fully appreciated their advantages.

As a total aside, in the shadow noise department, the drum scanners seem to exhibit strong posterization. I don't think it would show in most ordinary work, but what is the cause of this over the otherwise inferior scanners?

[sanking]

It should also be noted that the actual difference in sharpness between the high end scanners and the Epson flatbeds is even greater that the scanner comparison indicates. As noted in the review, The comparison was based on the assumption that a scanner's potential owner might want to produce a large digital print, so the scan resolution is 2400 ppi. This allows a 10x enlargement when printed at 240 dpi, yielding a 40x50 inch print."

Some of the drum scanners and high end flatbeds are capable of achieving "real" resolution 5000 spi and more so keeping it low tends equal the playing field for the consumer flatbeds that are limited in "real" resolution to 2400 spi or less (regardless of the optical resolution claimed).

Even with this limitation there is a huge differnence between the sharpness of some of the drum scanners compared to the Epson V750. Just compare the Howtek 4500 to the V750. By contrast, the difference between the 4990 and V750 at 2400 spi is to small to discern, or minimal at best.

Sandy King

Although I entirely agree with you on drum scans (though the Epson may give more then acceptable performance under certain conditions), I am not so sure about the professional flatbeds. Looking at the sample scans, they certainly did not knock my socks off like the drum scans, and might be debatable quality w.r.t. the Epson. I am not just talking about sharpness here, but more complete "feeling" of image quality I'll admit to not looking at all the samples, so may not have fully appreciated their advantages.

As a total aside, in the shadow noise department, the drum scanners seem to exhibit strong posterization. I don't think it would show in most ordinary work, but what is the cause of this over the otherwise inferior scanners?

[sanking]

I am assuming that I did test the high res system, for what that is worth. In a previous post an owner of an Epson V750 wrote, "The hi-resolution lens on the v700/v750 is NOT "activated" by scanning at 6400 spi. The lens in question is "acitvated" by scanning above the platen using the transparency w/ film holder options and has a reduced coverage area over the normal platen-level lens. The lens is employed for any resolution when scanning with a holder or mounting tray."

In my tests of the V750 I scanned a target directly on the glass, image side down, and with the target in a holder, image side down.

My testing of the 4990 indicated effective resolution of 1800-2000 spi, the V750 tested at 2100-2300 spi. I did not test Dmax of either. In practice I have found that the 4990 does a good job with color and B&W negatives, even fairly dense ones. I don't scan transparencies.

BTW, the following document at the Epson web site makes it very clear that the area covered when using the "high resolution/6400 spi" lens is less than with the "4800 spi" lens. http://www.photo.epson.co.uk/technol.../dual_lens.htm

Sandy King

QUOTE=PenGun;437972]Did you test the 'hi res' system?[/QUOTE]