Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: KenKovak on August 17, 2011, 01:22:28 pm
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Perhaps a bit off topic but I need some help. Can anyone point me in the direction of a flatbed scanner that has some depth of field? My wife does pressed flower art (see here: http://kenkphotography.smugmug.com/Dorothys-Creations/Dorothys-Pressed-Flower-Art/7417662_DdvFL#478016670_bpYC2 ) and we need some depth of field out of the scanner to deal with the thickness of the plant material. We do not need much dof, likely 4-5 mm would be sufficient.
Most of the images of here work were taken with my canon 40D and my macro lens, but setting that up can be a pain.
Thanks
Ken
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A Cruse scanner would be perfect for this. The quality of the scans are amazing.
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I scan jewelry periodically with an Epson V750 and the depth of field is satisfactory.
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scanners have a good amount of DOF actually doesnt matter which, around 1/4-1/2", vertically.
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scanners have a good amount of DOF actually doesnt matter which, around 1/4-1/2", vertically.
Yep, I've found this on cheap AIO's as well as my V700, in which I recently scanned a family crest plaque with about 1/2" depth with good DOF.
Pete
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Why do my scans come out so soft if there's a large DOF?
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Are you having fun Alan, or do you really expect someone can definitively answer this question? :-)
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Mark: that's a serious question. I have to really sharpen to no end and never get the sharpness I really want from my V600 flat bed. Also, if the vertical is 1/4'+, why is that company selling height adjustment film holders? Any experience you have to answer this would be appreciated as I'm really not that satisfied with my shots but don't wnt to spend the money to buy a Nikon scanner. Thanks Alan.
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Alan, firstly, if a scan is out of focus, sharpening won't help it much. Secondly, the V600 is a low-end product, so there is limit to what you can expect from it. Thirdly, nonetheless, it should provide a reasonably well-focused, decent resolution scan at least of flat documents (assuming you've set the resolution high enough). If it doesn't, this means there could be a hardware problem requiring a chat with Epson tech support.
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Why do my scans come out so soft if there's a large DOF?
There are two major types of scanning devices in flat bed scanners: CCD (charge-coupled device) array and CIS (contact image sensor). If I remember correctly, one of those has a shallower DOF, I am just not sure which one (but I think it is CIS).
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Thanks for the feedback folks.
Following on Slobodan's comment I did some further research. The CIS sensors have almost no DOF while the CCD sensors have at least some DOF.
The all in one scanner I have at home is a CIS which explains why I get unsatisfactory results.
The Epson Perfection line of scanners are all CCD. But it seems as if Alan gets poor results with his V600 (~$200) while Pete (V700, ~$600) and Mark (V750 ~$850) get good results wrt DOF.
Alan, any chance something is amiss with your V600?
Anyone else have experience with the V600?
Making the jump from $200 to $600 is tough to consider unless absolutely necessary.
Thanks
Ken
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It's not clear to me why the kind of sensor should influence DoF. DoF should be determined by focal length, lens aperture, distance from scan surface to lens.
it's probably a safe bet that lens quality will be better on a 800 dollar scanner than a 200 dollar scanner, but that may or may not be a determinative issue for Alan's problem, which I suspect is unit-specific. I doubt even at 200 dollars Epson would market a scanner that delivers systemically unfocused output. A read of the reviews may help determine this.
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Alan, firstly, if a scan is out of focus, sharpening won't help it much. Secondly, the V600 is a low-end product, so there is limit to what you can expect from it. Thirdly, nonetheless, it should provide a reasonably well-focused, decent resolution scan at least of flat documents (assuming you've set the resolution high enough). If it doesn't, this means there could be a hardware problem requiring a chat with Epson tech support.
Mark, although the V600 is a lower end product, the most comprehensive review I've read of it (Photo-i) rates its flatbed scanning IQ as good as the benchmark V700/750 at less than half the price, and much faster with its LED light source that needs little warm-up. It's film scanning IQ does lag a bit behind, though.
http://www.photo-i.co.uk/Reviews/interactive/Epson%20V650/page-1.html
Pete
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Good - so that means what I suggested to Alan is yet more a-propos. He needs to talk to Epson about HIS scanner.
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@Alan: The Nikon film scanners don't have terrific depth of field - in fact it sucks, IMO. The only saving grace is that you can pick your focus spot to try get the most out of it when the film has some curve in it.
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I appreicate everyone's responses but I think I overstressed my point about focus. The initial scan is soft focus but it does seem to sharpen up pretty much afterwards in Post for the most part. You can check my portfolio and provide your own opinions if they seem sharp enough. I just am wondering why it seems so soft though out of the scanner? (I don't sharpen during the scan as basically that's just post processing anyway).
Could someone also answer the question about how an adjustable film holder improves if the scanner has a height focus of 1/4"+ anyway???
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This may be of interest: http://thecatscan.tumblr.com/
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Manufacturing tolerances, for one thing Alan. Calibration could also get a bit out of whack in shipping or in set up. If the scanner is moved around it could throw things out a bit.
Scanners are like digital cameras. The Epsons, for example, have a CCD array - Red, Green and Blue. Similar processing to what a camera does needs to be undertaken to produce a final image. The result is a bit of softness that sharpens up nicely after the fact.
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The best DOF I have ever experienced was from a Nikon AX1200 (re-badged Umax) mid-’90s; it had surprising depth. Various Epsons since have been OK and focusable (focus stacking? :), but have read that a lot of the Canon LIDE scanners were very shallow.
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I just am wondering why it seems so soft though out of the scanner?
Alan,
I replaced my aging Canon 9xxx flatbed with a lowly V500 (just for prints) and find the results quite good considering the price paid. I have not noticed any soft scans unless they were soft prints to begin with. It is possible something was knocked out of alignment during shipping(?) or some other problem with your particular flatbed.