Scanners with no raised rim

Started Dec 10, 2010 | Discussions
cbnphoto New Member • Posts: 17
Scanners with no raised rim

Sorry for this being a scanner question, but there is no forum more appropriate than this one.

Can anyone recommend an A4 flatbed scanner that has a flush top, i.e.: no raised rim or lip. I need to scan some large maps (larger than the scanning area of A4) and want them to lie flat on the scanner so I can scan them section by section and then stitch the scans in photoshop.

I'm not interested in A3 or larger scanning solutions - too expensive for me (and unless they are A0 size would not be any better).

Thanks.

Zone8 Forum Pro • Posts: 17,276
Re: Scanners with no raised rim

As far as I am aware, all have a lip - essentially to provide a guide for paper positioning.

As most scanners use lenses (so can scan 3D objects) if you can access a scanner and put on top, say, a piece of glass from perhaps a photo frame, then do a scan and check the sharpness of one of the maps or whatever in that scanned area. If that works OK, you have the solution - just then get a piece of thin glass cut to fit inside the opening, so then the maps etc. would not be restricted by the rim in terms of being flush at edges.

I am pretty sure this would then enable any scanner to do what you require.

-- hide signature --

Zone8

The photograph isolates and perpetuates a moment of time: an important and revealing moment, or an unimportant and meaningless one, depending upon the photographer's understanding of his subject and mastery of his process. -Edward Weston
http://www.photosnowdonia.co.uk/ZPS

Vernon D Rainwater Forum Pro • Posts: 13,918
Re: Scanners with no raised rim

Zone8 wrote:

As far as I am aware, all have a lip - essentially to provide a guide for paper positioning.

As most scanners use lenses (so can scan 3D objects) if you can access a scanner and put on top, say, a piece of glass from perhaps a photo frame, then do a scan and check the sharpness of one of the maps or whatever in that scanned area. If that works OK, you have the solution - just then get a piece of thin glass cut to fit inside the opening, so then the maps etc. would not be restricted by the rim in terms of being flush at edges.

I am pretty sure this would then enable any scanner to do what you require.

As mentioned, scanners have an edge (slightly higher than scanner glass), however, I have scanned many large documents and pictures on my Epson V700 and have no issue with the slight edge. The scanner lid does a good job of holding the source media (picture, map, or document) in place.

I use PTGui Panorama Program for assembling all the scans into ONE file. The image overlap area I use is part of the reason there is NO issue with the edges. I have never used Photoshop for the assembly part of the operation so have no idea regarding quality regarding using Photoshop vs PTGui.

Just my opinion: The proper overlap of the scans is the most important part of the entire process. I use 20 to 25 % overlap and it works without issue. Never would I use a method for this type of scanning that uses basically a VERY small overlap. This is basically the same principal as exposing images for Panorama scenes.
--
Vernon...

Hugowolf Forum Pro • Posts: 12,674
Re: Scanners with no raised rim

Vernon D Rainwater wrote:

Zone8 wrote:

Just my opinion: The proper overlap of the scans is the most important part of the entire process. I use 20 to 25 % overlap and it works without issue. Never would I use a method for this type of scanning that uses basically a VERY small overlap. This is basically the same principal as exposing images for Panorama scenes.

It really shouldn’t need such a large overlap. Panoramas taken with a camera and lens have many more edge problems than you should get with a decent scanner. Lenses, no matter how good, suffer from edge fall off, vignetting, geometric distortions, and often lower resolution at the edges and corners.

Brian A

BobSC Veteran Member • Posts: 4,404
Re: Scanners with no raised rim

I got a MUSTEK A3 scanner because it was really cheap. Currently $150 for 1200 dpi. I got it specifically because I was going batty scanning A0 size documents on an A4 scanner.

If you're scanning A0, You'll have 4 sections with an A3 scanner, instead of 25 with A4. 4, because assuming you have some margins on the original, you'll have enough overlap to do the jointing, but 25, because you'll need to overlap each segment. Just naming the 24 scans is aggravating. Also, 4 scans are easy, because you do one in each corner. With 16 to 25 it gets more difficult to get the positioning and alignment You end up spending a lot more time trying to figure out which segment needs to be rotated to get things to line up.

The lip is no problem. You just take the lid off and set it down on top of the map.

You need to overlap the scans, because it's nearly impossible to exactly maintain orientation, and you'll need to rotate a bit here and there. It's much easier to do with 4 segments than 25!

If this is a one-off project and if the maps are loose pages, you might want to consider taking them someplace and having it done. It usually only costs a few $ per page.

Another option, depending on how much detail you need, is to hang the maps in even light and photograph them.

Vernon D Rainwater Forum Pro • Posts: 13,918
Re: Scanners with no raised rim

Hugowolf wrote:

Vernon D Rainwater wrote:

Zone8 wrote:

Just my opinion: The proper overlap of the scans is the most important part of the entire process. I use 20 to 25 % overlap and it works without issue. Never would I use a method for this type of scanning that uses basically a VERY small overlap. This is basically the same principal as exposing images for Panorama scenes.

It really shouldn’t need such a large overlap. Panoramas taken with a camera and lens have many more edge problems than you should get with a decent scanner. Lenses, no matter how good, suffer from edge fall off, vignetting, geometric distortions, and often lower resolution at the edges and corners.

Brian A

Brian, perhaps you are correct, however; the added overlap certainly will not contribute to degrading the final assembled image. If I were using a slower computer it might be worth trying to get by with (perhaps one less image) to assemble for the final image but I have no problem with the processing with the (More than Generous) overlap that I use..
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Vernon...

Vernon D Rainwater Forum Pro • Posts: 13,918
Re: Scanners with no raised rim

BobSC wrote:

I got a MUSTEK A3 scanner because it was really cheap. Currently $150 for 1200 dpi. I got it specifically because I was going batty scanning A0 size documents on an A4 scanner.

If you're scanning A0, You'll have 4 sections with an A3 scanner, instead of 25 with A4. 4, because assuming you have some margins on the original, you'll have enough overlap to do the jointing, but 25, because you'll need to overlap each segment. Just naming the 24 scans is aggravating. Also, 4 scans are easy, because you do one in each corner. With 16 to 25 it gets more difficult to get the positioning and alignment You end up spending a lot more time trying to figure out which segment needs to be rotated to get things to line up.

The lip is no problem. You just take the lid off and set it down on top of the map.

You need to overlap the scans, because it's nearly impossible to exactly maintain orientation, and you'll need to rotate a bit here and there. It's much easier to do with 4 segments than 25!

If this is a one-off project and if the maps are loose pages, you might want to consider taking them someplace and having it done. It usually only costs a few $ per page.

Another option, depending on how much detail you need, is to hang the maps in even light and photograph them.

You make a good point if using Photoshop and manual aligning the hard way.

PTGui does all the aligning with no operator assistance. Even if the images are NOT aligned in proper sequence when opening in PTGui, it will select and align them to assemble the final image.

Also, using the Epson Scanning software that ships with the V700, the file identification (numbering, etc) is handled by the scanning software.
--
Vernon...

Hugowolf Forum Pro • Posts: 12,674
Re: Scanners with no raised rim

Vernon D Rainwater wrote:

Hugowolf wrote:

Vernon D Rainwater wrote:

Zone8 wrote:

Just my opinion: The proper overlap of the scans is the most important part of the entire process. I use 20 to 25 % overlap and it works without issue. Never would I use a method for this type of scanning that uses basically a VERY small overlap. This is basically the same principal as exposing images for Panorama scenes.

It really shouldn’t need such a large overlap. Panoramas taken with a camera and lens have many more edge problems than you should get with a decent scanner. Lenses, no matter how good, suffer from edge fall off, vignetting, geometric distortions, and often lower resolution at the edges and corners.

Brian A

Brian, perhaps you are correct, however; the added overlap certainly will not contribute to degrading the final assembled image. If I were using a slower computer it might be worth trying to get by with (perhaps one less image) to assemble for the final image but I have no problem with the processing with the (More than Generous) overlap that I use..

I agree, there is no harm in being over cautious, except with A0 from A4, 25% overlap is a lot more than one extra sheet.

Brian A

Lightight Forum Member • Posts: 62
Re: Scanners with no raised rim

You might just try to avoid the entire issue and simply photograph your maps with a high pixel digital camera. Just lay it out flat on a copy stand and be sure your camera is level and parallel to the stand. Why spend money on a scanner you will only use occasionally?

David G

BobSC Veteran Member • Posts: 4,404
Re: Scanners with no raised rim

Vernon D Rainwater wrote:

You make a good point if using Photoshop and manual aligning the hard way.
PTGui does all the aligning with no operator assistance.

Oooh. (light bulb turns on above head).

Good idea. Thanks! I've used PTGui for panos but not for scans. I'll be doing it that way in the future.

The A3 scanner is still cheap, and requires fewer scans.

OP cbnphoto New Member • Posts: 17
Re: Scanners with no raised rim

Lightight wrote:

You might just try to avoid the entire issue and simply photograph your maps with a high pixel digital camera. Just lay it out flat on a copy stand and be sure your camera is level and parallel to the stand. Why spend money on a scanner you will only use occasionally?

Thanks for your comment.

I have already tried that route. I even went to the trouble of making an air table to suck the maps flat (they are folded maps). The problem lies in the fact that a) to get the resolution I need I'd need to take about 15 to 20 pictures of each map and that's a real hassle to do accurately*. Second issue is parallax effects. I need the maps scanned face-on with almost no geometrical distortion.

Scanning would be a whole lot easier.

  • equipment: 1DsIII + 100-400L.

Vernon D Rainwater Forum Pro • Posts: 13,918
Re: Scanners with no raised rim

BobSC wrote:

Vernon D Rainwater wrote:

You make a good point if using Photoshop and manual aligning the hard way.
PTGui does all the aligning with no operator assistance.

Oooh. (light bulb turns on above head).

Good idea. Thanks! I've used PTGui for panos but not for scans. I'll be doing it that way in the future.

The A3 scanner is still cheap, and requires fewer scans.

Hopefully, (the below info) may save some time in getting the best results. I have included details for part of the information in the user information for PTGui.

I use this information when processing scanned images (in parts) for pictures, Documents, Maps, and any other Source Media that is larger than the Scanner Maximum size.

-- hide signature --

Vernon...

OP cbnphoto New Member • Posts: 17
Thanks

Thanks everyone for your comments. Much appreciated.

We have an HP scanner at work that has a flush surface and small rubberised transparent blobs at the four corners for paper positioning, so I wondered if there was a scanner going all the way and foregoing even those. I might have to purchase a second-hand one of these and scrap the corner positioner bits off - then I'll have what I want.

cheers,
c.

ronzie Senior Member • Posts: 1,288
Re: Thanks

Place a thin piece of white cardboard sized and positioned to your imaging glass secured with removable tape to the scanner lid to increase the force on the map in the imaging area if needed. Weight the lid if needed.

See if that helps.
--
Ron Ginsberg
Minneapolis, MN
Land of 10,000 Puddles

Zone8 Forum Pro • Posts: 17,276
Re: Thanks

My idea of a thin glass overlay is surely the best way to go, especially as it does not alter the business scanner which I now gather is not yours? That would be a lot cheaper than purchasing one for yourself, unless you envisage using it a lot for the same purpose.

In any event, the glass is inexpensive and would immediately (if not sooner) convert any scanner, without need for alteration. You can then also wash the glass between uses in one of those convenient puddles!

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Zone8

The photograph isolates and perpetuates a moment of time: an important and revealing moment, or an unimportant and meaningless one, depending upon the photographer's understanding of his subject and mastery of his process. -Edward Weston
http://www.photosnowdonia.co.uk/ZPS

ronzie Senior Member • Posts: 1,288
Re: Thanks

I wonder if a glass overlay could cause Moire' problems in the surface contact between the two glass surfaces.

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Ron Ginsberg
Minneapolis, MN
Land of 10,000 Puddles

Dominic.Chan Veteran Member • Posts: 6,168
Re: Thanks

ronzie wrote:

I wonder if a glass overlay could cause Moire' problems in the surface contact between the two glass surfaces.

Possibly. The orverlay will also cause the scan to be somewhat out-of-focus.

Vernon D Rainwater Forum Pro • Posts: 13,918
Re: Thanks

ronzie wrote:

I wonder if a glass overlay could cause Moire' problems in the surface contact between the two glass surfaces.

I used "Optical Quality Glass" with an Omega D2 4 x 5 inch Negative Enlarger for some projects several years ago. First I tried clean and "seemingly" clear pieces of normal flat glass and I had problems with "Ghosting" due to light refractions (or perhaps Morie) when trying to use that type glass.

I believe the "Optical Quality Glass" should work properly with a flat bed scanner such as discussed in this thread -- providing the glass thickness is proper to NOT cause an "out of focus" issue,-- however; never would I use normal flat glass for that purpose.

My primary usage with the Optical Glass (in fact, I used 2 pieces) that I placed badly damaged Negatives between the two pieces of Optical Glass -- with both sides of the negative(s) coated with a "Jell" substance so to almost eliminate the effects of negative scratches and other damage.

I had no issues with any type of potential "OUT of FOCUS" such as may be experienced when using with a flat bed scanner -- since the Enlarger Focusing method was not affected.
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Vernon...

richardplondon
richardplondon Forum Pro • Posts: 10,892
scan in one?

As an alternative to buying a special scanner, it may be worth pricing out large format scanning from a reprographics bureau. Massively quicker and easier to get an accurate and consistent end result.

If you work in, or know anyone in, a construction or engineering or geological etc field, you may manage to get the job done at trade account discount prices, rather than walk-in-off-the-street ridiculous list prices.

Also many large construction firms, local government planning departments etc have their own large format scanner and do this kind of thing all day long. If you have a suitable contact, a favour or two to call in, it costs nothing to ask

RP

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pocketfulladoubles Senior Member • Posts: 1,986
Re: Thanks

I think Zone8 probably has it right. At least for transparency scanning (don't think reflective would be different though?) the focal plane of say, an Epson flatbed is actually not on the glass. It's slightly above it, which is why they give you film holders. Unfortunately, Epson's film holders do not allow for height adjustment like 3rd party ones do like the Betterscanning holder. They also use anti-Newton ring glass. If you could find the focal calibration height and buy a sheet of optical glass with that thickness I think your problem may be solved.

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