CLPEX Chat Board

I'll comment on ER's statement that using a camera gives up quality for speed.

There are several issues, which I'll list below - but, any decent camera gives you so much information, that it's kind of a wash anyway. It's kind of like, once you have $100,000,000 in savings, why do you need any more?

1) Flatbed scanners use tri-linear arrays, so there is no color interpolation, but most cameras use a color matrix filter on the sensor so that the color information must be interpolated, causing a loss of sharpness.
2) Most cameras also have an anti-aliasing filter in the optical path to purposely blur the image.
3) Although one can have good lighting in either case, the light in a flatbed scanner is consistent and even every time.
4) With large subjects (palm prints, foot prints, etc.) a scanner can create a higher resolution (based on pixel density) image than a camera.

Of course, there is another side to this as well. Some advantages to shooting with a camera include:

1) With small objects, you can photograph at a higher resolution (based on pixel density) than you can scan.
2) Cameras can photograph in raw, which can have advantages over rendered formats.
3) Sometimes lighting techniques that aren't possible with a scanner are needed.

And, regarding the speed issue. I'm not sure which is faster - it kind of depends on one's set-up. My conclusion - use the best tool for the job; sometimes that will be a camera, sometimes it will be a scanner. And, use them correctly. When I provide training, I find that many latent examiners don't have their scanners set up correctly, and they don't photograph latents as they should.

Thanks for the reply George. Your explanation makes perfect sense. I normally prefer to scan whenever possible. (ninhydrin, CV, etc) but if someone would come up with a 532nm scanner (that my agency could afford) I would jump up and down with uncontrollable glee.

I'm not sure that speed is necessarily an issue either way. This goes to your comment that it depends on the individual setup. I have found that setting up a shot with a camera and setting up a piece of evidence to scan each have their own nuances which can take time. (when they are done correctly) I guess that was my main source of confusion with the ER's post. Speed just wasn't something I was considering that favorably between one or the other process.

If a camera is dedicated only to photographing lifts at 1000ppi, then there is no setup of each shot, and the process can be much faster than scanning. All I was trying to say is that there are other things to consider besides speed, including the issues listed above.

ER wrote:...All I was trying to say is that there are other things to consider besides speed, including the issues listed above.

I can wholeheartedly agree with that.

Getting back onto the topic of working upright, I had the opportunity to work with a Wacom tablet at my last agency. I have to say that once I got used to it and set up the customizations I wanted to the tablet's buttons I could work through a lot of prints in a short amount of time. Being able to see the prints full-screen on the 27" tablet certanly made the difference. We used it in combination with Photoshop CS5 and our workflow was completely paperless, although we could print if necessary. Verification packets were interestingly done using the contact sheet automation script in PS. Of all the gadgets I had access to, I miss that tablet the most.

ER
That is a very broad stroke to be using; so how do you use a scanner on a broken piece of plastic cowling from around the smashed ignition switch where the fingerprint is developed with superglue and stained with basic 40 (or the barrel of a revolver) etc etc. What kind of camera are you referring to? There must be a place for both I can not see that you can say one is better than the other.
Have AFIS systems stopped compressing the images from the scanners yet???


TSBUSBY
Many years ago we had a colour video camera set up similar to the one shown (but via a microscope) and it was ok though I would not suggest it would replace a X5 magnifier. The higher magnification made it harder to find the right spot, and it was used very rarely. We also had a video camera connected to a monitor and computer; this set up was much better though once again I would not suggest it would replace a X5 magnifier. But I am only thinking fingerprints here you may not be.

I should have been a lot more specific from the start. TSBusby asked how people capture lift cards. Briano responded that he uses a camera. I assumed that he uses a camera over a scanner for speed. There are other issues to consider in choosing to use a camera instead of a scanner besides speed. (see above) Of course, there are plenty of applications where a camera is always preferable to using a scanner. The question posed in this thread specifically refers to capturing lift cards.