Duplicating UV markings

[meestaeimaj]

Hi there,

Does anyone know how I can obtain a scan or an electronic image of an ID marking from a piece of paper say ? Just so that the marking can be played about with in photoshop and the like. Obviously these can be illuminated with a black light but how would one then obtain an electronic image of this without elaborate use of optics etc. ?


Thanks in advance - GREAT forum you guys have here.g

[Jacks Complete]

This is a pretty good question.

If you use a flatbed scanner, you won't be able to see the UV watermarking, etc. clearly. I would suggest that you use a quality camera, set to around the middle of the zoom range for minimum distortion, and take a photograph of the target from a tripod, while lighting it with a UV lamp. Do this in a closed room, and use the focus lock once you have a good image, then turn on the UV and turn off the regular light. I would suggest taking one intermediate photo, too, for calibration.

[bipolar]

I have also thought about the idea. You could somehow replace the lights in scanner with a bar of UV LEDs. They did this with blue LEDs to see the yellow tracking dots well from laser printers.

Of course that would be time consuming and take a bit of skill. I agree the best way is to do as Jack described. Basicly like using a copystand with a high res digital cam for getting almost a scan of a paper or photo.

The same should work with UV. You may still have to do some redrawing.

Multi-colored invisible UV inkjet printer cartridges are available now on the web, or fill them with the ink yourself.

[FUTI]

Hi people, this post is somewhat unrelated to this topic, but I will ask here anyway.

I have tried to convert a old scanner in a similar way. I want to use one of those UV-CCFL lamps that are usually sold for "cosmetic" purposes (you know when some k3wl want their PC have thematic look (like Doom or Quake inspired) and put a load of blinking, flashing lamps, see-through covers, eariee fans and other stuff in its case). But I have a problem. Since I live in funny corner of the world, I can't find a firm that distributes those things. If anyone can help me, please send me a PM. I will post a results if I obtain good one.

Just to state that I need this for scientific purposes only and I don't make fake IDs, money or whatever they tried so far to protect with UV markings.

[Jacks Complete]

I think you will have trouble getting the UV to go through the glass on the scanner bed if you swap out the lamps.

You can get UV LEDs that use a phospor to produce UV, I have one on a keyring. That would probably work, if it will transmit through the glass.

To scan the yellow laser dots, you can simply use the scanner like normal, then edit in software to se the dots, just use 600+ dpi.

[FUTI]

I want to replace the glass on a scanner too Jack but that isn't to much of a trouble for me (that I can find here)...some specific optical elements I desperately search for are those lamps (not the UV LED type though) and some filters for the old hand-held UV-lamp my lab has but since filters are almost destroyed it is hardly alive. Can anyone help me about it?

[Anira]

You might want to try holding a black light on the other side of the paper and seeing if it illuminates well enough.

If it doesnt work.. then get a tripod, black light, a wall, some thumb tacks, and a camera. Tack the item to the wall at the same height as the lense. Zoom in on what you want, if its large, zoom in on a quarter, maby less. Take pictures of it by turing the tripod head or if you want best results, I would recomend moving the tripod side to side and up and down. Be carefull to move it and not rotate or adjust the distance, doing so would cause your post preduction work to get a lot harder (still easy with photoshop but often time consuming and hard if you are not well aquanted with it).

[FUTI]

I did try that Anira, but you wouldn't like to see results. Experiment was like this...plug out scanner lamp, place paper, lamp above the paper, scan. Unfortunately light intensity of a lamp is much higher that scanner lamp so you have unequall illumination. In one sentence... it is well beyond enough illumination. I could try to work in a dark room and reduce illumination by removing light source to a "trial-and-error-determined" distance to correct that problem.

But I want to made my scanner use UV lamp as a light source. Scanners work best if they reflect light of some object, when it comes to films they handle them much worse (and only recently scanners become fitted to scan slides, negatives etc.) we already discussed that subject here...I tried that too and have some poor results..but I'm not giving up that easy. Physics behind poor performance of scanners with films compared to paper is easy, so back illumination is a good choice. I have an idea that could kill two flies with one stroke...UV lamp for scanner and fluorescent background cover. That way I hope to get UV reflection image on some objects, and pass through visible image on other. NBK knows what I talk about. NBK can you help with that purchase?