# Question about web camera quality resolution

hi all

i just bought a non-hd web camera

the dealer said its 25 mp camera

but when i used it and took images then they are like of poor quality.

then i read on the manual which says its 25 mega pixel (interpolated)

So what about HD Cameras ??

are hd cameras also have same interpolated resolution quality ??

how can i calculate and find the actual mega pixel ??

25 interpolated mega pixels are equals to how many actual mega pixels ??

i want to know these answers so that next time i buy a web camera then i get decent photos with it

vineet

A mega pixel is 1000000 (million) pixels. To calculate the number of pixels in an image multiply the height and width of the image in pixels. To get mega pixels, divide by 1000000.
Example, a photograph 4000px by 3000px is `4000 x 3000 = 12000000` thatâ€™s 12 mega pixels.

If the image is interpolated up from a lower value, it will be hard to find the original value, unless stated in the documentation.

Always read the small print.

hi SamA74

it shot the images at 640x480

so that means it is having 0.3 mp resolution quality

vineet

That is not HD, that is know as VGA resolution, the same as the old VGA computer displays.
It works out at 0.3 Mpx. (307200 pixels in total).

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hi SamA74

do you know what is the minimum resolution mega pixel resolution of HD

if i buy an HD Webcam what will be the minimum quality i will get ??

Vineet

The smallest resolution that is considered HD is 1280x720, but full HD is 1920x1080. Thatâ€™s only 2 Mpx, but thatâ€™s good for video. But still cameras usually have better resolution. There are now 2k and 4k video cameras out there, but thatâ€™s probably overkill for casual use or a web cam.

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hi SamA74

see the below 3 links

they all have 720p hd quality (1280x720)

http://www.logitech.com/en-in/product/hd-webcam-c525?crid=34

But in the technical specification they have different resolution for photos only
Photos: Up to 3.0 megapixels (software enhanced)
Photos: Up to 5 megapixels (software enhanced)
Photos: Up to 8 megapixels (software enhanced)

So does that mean that video quality of all 3 cameras will same but Image quality will different ??

so do you think image quality will be different between these 3 webcams ??

What does software enhanced means. Do i have to use some software to improve that photo mega pixel quality ??

vineet

Thatâ€™s what it sounds like. All have video res of 1280x720 which I think is quite sufficient for a web-cam. But it is strange that the still res differs, so it could be that the C525 has a superior sensor, but I canâ€™t be sure from the specs given on the page.

Iâ€™m not sure, itâ€™s a bit ambiguous. I suspect it may be something similar to â€śinterpolatedâ€ť, as in the image is captured at a lower res and scaled up.

No, I suspect that there is software within the camera which â€śenhancesâ€ť automatically on capture.
Whether this is suitable for you really depends upon your needs.

yes they have confusing facts and specs

vineet

vineet, if your camera has a 25MB rez sensor, that is more than enough pixels to take a very sharp photo, even if 25MB is an interpolated number.

When you took the photos at 640x480, you were only using a fraction of the available resolution.
307KB instead of 25MB. That is why your photo looks grainy or low-rez. You only used a fraction of the pixels in the sensor. You can store on your memory card a jillion more photos that were taken at 640x480 than you could if they had been taken at your highest rez.

Want higher rez? shoot higher rez.

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Hi ronpat

i didnt find any option to select and shoot high resolution images ??

where will that option be ??

vineet

Can you give us the URL to the userâ€™s manual for your camera?

Those numbers do not make sense.

Hi ronpat

i bought this non-hd webcamera yesterday.
here is the link
http://qhmpl.com/QHM495LM-Web-Camera.html

vineet

They donâ€™t much in the spec.

Interpolated to 25 Mega Pixels

25 Mega pixels is quite high-res, but not if itâ€™s been interpolated from a much lower size.

Resolution Hardware : 500K pixels

I guess that means itâ€™s only a half mega pixel sensor.
Thatâ€™s not enough to blow up to 25, it would look awful.

Personally I donâ€™t agree with all this blowing images up and calling it a higher resolution, the same goes for â€śdigital zoomâ€ť, itâ€™s all a bit of a nonsense to me.
I also never liked the unit â€śmega pixelâ€ť. To me itâ€™s more meaningful to say how many pixels wide and high. I always felt that mega pixels was a form of â€śdumbing downâ€ť for the consumer market, but it seems to have become the standard unit of measure for camera resolution.
Am I ranting?

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This looks like an outdated bare-bones desktop cam with creative claims of quality. Hardware rez is listed as 500K. Thatâ€™s about 60% more than 640x480 would account for. Those â€śextraâ€ť pixels are used for real-time focusing and exposure control while the vid is behing shot. You would have to buy a camera with a highter resolution sensor to take sharper images. Definitely donâ€™t buy into the marketing claims of super-hi rez when the hardware doesnâ€™t back up the claim.

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