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Thread: Need some suggestions on a webcam

  1. #21
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    Feh, a webcam for $9 with a 640x480 sensor claims resolution to 50 Mp I've really got to wonder about the sensor native resolution in cheap cell phones, too.

    This is just fancy sales-speak for software interpolation. You're still getting 0.3Mp of data; just fudging things to create detail that isn't really there. It seems that most inexpensive webcams do exactly this.

    So far, a still photo camera seems to be the best bet. I could even put my old Minolta Dimage 7hi to use--it's got real glass in the lens, but it drinks batteries like there's no tomorrow. Probably overkill for the application.

    I dug a cheap webcam out of my hellbox and checked the field of view. To do 12"x12", you have to be back about 4 feet. Lens claims it's a 3.85mm FL.
    Last edited by Chuck(G); March 31st, 2019 at 09:14 AM.

  2. #22
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    After more research it appears that many of the web cams claiming higher resolution are achieving it through interpolation: As you suspected, 640x480 is the "native" resolution and anything higher is interpolated.

    I was able to perform a test using your specifications (24 inches distance, coverage of a 12x12" field of view) using a Nikon Coolpix digital camera. The image data notes that the lens focal length was 11mm at the time of exposure; Nikon states the camera's focal range is 4.6 to 22mm, the equivalent of 26 to 130mm on a 35mm camera. So the lens was about the equivalent of a 50mm lens on a 35mm camera. Somewhere between 40 and 60mm equivalent focal length.

    Nikon says the sensor has 5152x3864 pixels, which they describe as "20 megapixel". The results were decent enough to image and recover through OCR a page of text varying from 8 to 18 points in size. This Coolpix (L32: https://www.nikonusa.com/en/nikon-pr...Tabs-TechSpecs) does not offer a RAW image format but stores everything as JPEG (not the best for image processing but okay as long as you don't monkey with it).

    Focus was a little soft at the edges, as might be expected. The camera has a USB port and can transfer images to the PC for further processing (Nikon offers a suite of tools for free) but "tethered" shooting, where the PC software triggers the camera and prompts it to transfer the image back automatically, is not featured on this low-end, "point-and-shoot" camera. It runs on 2 AA rechargeables and they last a long time between charges.

    For video conferencing a web cam might be the best solution but for your task I think a low-end digital camera would perform better and maybe even cost less. I stand corrected.

    -CH-

  3. #23
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    I investigated the so-called "document cameras" that, it would seem are made for the purpose. However, at best, most seem to cover only 12"x9". There may be others, but the have integrated copy stands and get to be very pricey.

    I'll stick with my digicam, I guess.

  4. #24
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    Quote Originally Posted by Chuck(G) View Post
    ...I'll stick with my digicam, I guess.
    Wire a footswitch across the shutter and Bob's your uncle.

  5. #25
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    I guess I can simply push a button as well...

    What's surprising to me was the hype around webcam resolutions, when it seems that most of them use a 640x480 sensor and then interpolate the heck of the result. 50Mp? Wow. I wonder if it's the inability of USB 2.0 to maintain at least 30 fps unless fewer pixels are sent.

    Oh well, my eyes have been opened. :shrug:

  6. #26
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    Quote Originally Posted by Chuck(G) View Post
    I guess I can simply push a button as well...
    Of course, but I'd think for photographing a bunch of anything one at a time a footswitch would be more convenient.

    Another kludge I've used is to remove the ball from an old mouse, position the cursor over the 'take the picture' button on screen, and use it as a (wireless?) foot switch.

    Considering that old multi-MP digital cameras with zoom and all sorts of settings are plentiful and cheap (or free), why even think about a webcam.

  7. #27
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    This discussion got me thinking that maybe I should change my workflow.
    I've been using a flatbed scanner for tape media, which works, but risks scratching the bed.
    I decided to shop around and decided to get a hovercam solo 8 plus.
    https://www.thehovercam.com/solo8plus/
    https://www.ebay.com/itm/143164374588

  8. #28
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    Here's a possibility: Has 14 megapixel sensor, glass 5x zoom lens, Nikon image quality, comes with a wireless remote control and you can also get an interval timer for it. $55 used on flea-bay.

    https://imaging.nikon.com/lineup/coolpix/s/s1100pj/

    -CH-

  9. #29
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    I'm pretty sure the original requirement was the webcam because he didn't want to move media back and forth and the webcam would allow it to be stored right on the computer. I think Chuck already has an acceptable camera but was just trying to increase the efficiency of the process.

    That does give me another thought. Perhaps an eye-fi (wifi enabled) SD Card? I've seen them super cheap at the swapmeets and stuff, I actually almost got one a few times but couldn't fathom why I'd need one in this day and age, but that might allow the best of both worlds (A regular camera and a way to automatically store the photos onto a computer)
    -- Brian

    Working Systems: Apple IIe/II+/Mac+/Mac 512k, Atari 800/520STFM, Commodore 64/Amiga 3000/PET 4032/SX-64, IBM PS/1 2121-B82, Kaypro II, Osborne 1, Tandy 1000 SX, TI-99/4A, TRS-80 Model 4 GA
    Project Systems: Amstrad PCW 8256, Kaypro 2/84 (Bad Chips: 81-194, 81-189).

  10. #30
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    With my Canon , I can get the resolution I'm after with good glass lenses. The 2GB card limit is no issue. A USB cable will link the camera. So no biggie. If I don't like the Canon, I can try my Minolta D7Hi--although dated, it's got very good glass and a Sony sensor. I don't really use it any more--might as well do something with it, lest it suffer the same fate as my Nikon F2--disuse and dust.

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