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gary_hendricks
03-18-2005, 07:51 AM
Here is an article I published on my website about the number of megapixels needed in a digital camera. I hope it'll be useful to some of you in this forum.

How Many Megapixels Do You Really Need in a Digital Camera?
by Gary Hendricks

If you're out buying a digital camera, then one of the key deciding factors is the number of megapixels supported. The number of megapixels determines the how good your photos turn out. If you have too few megapixels, then your pictures will turn out crappy. Investing in a camera with too many megapixels, on the other hand, is an unnecessary waste of money.

Personally, I feel that if you have unlimited funds, then, by all means go for that high end 8 megapixel camera. Otherwise, you certainly don't want to waste money on extra megapixels you don't need.

A golden rule to bear mind: a camera with more megapixels isn't always better. If your camera supports more megapixels, then each photo you take will be larger. This means that you'll use up more space on your memory cards and computer's hard drive.

If you have trouble deciding how many megapixels you need (I know I did when I bought my first digital camera), then the guide below will help. Essentially, you need to ascertain what size prints you want to get and what your budget is, before deciding on how many megapixels you want. So here we go:

1 megapixel or less: Cameras in this range (e.g. web cameras or cell phone cameras) have very low image resolution. Don't expect to be able to print high-quality photos using these cameras. You can, however, email the photos or post them on your web site. The good thing about such cameras, of course, is their low price.

1 to 2 megapixels: My first digital camera was a Canon PowerShot S110 which only had a 2 megapixel sensor. Cameras in this range are pretty decent though - you can expect to print out great 4x6 prints at this resolution. Of course, if you want larger, blown-up protraits of your birthday party or holiday in Italy, then I would certainly recommend getting more megapixels. Cameras in this range should sell for around $100 currently.

3 to 4 megapixels: Most new point-and-shoot cameras these days tend to have at least 3 to 4 megapixel image resolution. Bring these images to the lab and they'll be able to develop great looking 4x6, 5x7 and even 6x9 printouts. Expect to pay slightly more though - we're looking at around $250 for a good model.

5 megapixels and up: The more advanced cameras tend to have image resolutions of 5 to 8 megapixels. Newer point-and-shoot cameras have 5 megapixels, while the newer digital SLRs come with 8 megapixels. The quality of images shot by these cameras is simply stunning. Of course, their price tags are equally stunning . In this megapixel category, expect to pay around $300 for a 5 megapixel camera and up to $1800 for an 8 megapixel SLR.

Conclusion
Well, now you know roughly the number of megapixels you should be shooting for depending on your intended usage and budget for the camera. My general advice is, if you're just an amateur photographer, then don't buy cameras above 5 megapixels. When you are really serious about digital photography and want to go professional, then consider buying a super high megapixel camera.

Within
08-05-2005, 07:18 AM
Sry for my silly post :), as I am new to this forum.

5 megapixels and up: The more advanced cameras tend to have image resolutions of 5 to 8 megapixels. Newer point-and-shoot cameras have 5 megapixels, while the newer digital SLRs come with 8 megapixels. The quality of images shot by these cameras is simply stunning. Of course, their price tags are equally stunning . In this megapixel category, expect to pay around $300 for a 5 megapixel camera and up to $1800 for an 8 megapixel SLR.

Does the megapixels really play an important role in the picture quality like during a telephoto zoom? I have taken several pictures using my S2 at full optical zoom. However, the quality is worse than a picture taken at lesser zoom length but better than a picture taken at full digital zoom. Does the zoom affect the quality or the megapixels or it has to do the focal lengths???

Thanks

Rob vdKam
08-05-2005, 07:36 AM
I hope you get some answers to this from more knowledgeable people. I haven't yet decided on a camera (Canon S2, Sony H1, or KM A200?) but I have been asking questions here and there and have been told that as long as the lens on a 8MP camera can pick up the same details that an optical zoom can see by zooming in, it's really the same in the end - just crop the 8MP to 4 MP and you double the zoom. Or you can avoid cropping by framing the subject using 2x digital zoom on an 8MP camera giving 4MP and double the lens zoom. I haven't tried any of this yet.

I'm not sure what you mean by quality being worse at full optical zoom compared to wide angle. Are you talking about focus, shaking, colour, or what?

Rob vdKam
08-05-2005, 07:42 AM
Make that 1/4 the pixels for doubling the zoom - the picture elements are length x width so halving them means a quarter of the total number. But I've printed many good plain paper pics from my 2 MP Canon snapshooter (775).

Within
08-06-2005, 07:44 AM
Thanks a lot for your tip. I am refering picture quality as in focus because I do not seem to get the kind of image most people have taken in comparison with my pictures.

My main use for my camera is to take pictures of birds which require minute details for identification, so I tried many times with different ISO, Shutter speed, aperture, white balance but still could not get the clear detailed pictures.

For e.g. I saw a bird at 50m away. At full zoom, 12x, I took a shot. I could see the outline of the bird and the shape of it which helps when seperating different groups of birds like differentiating eagle from sparrow. However, I was unable to capture the original colors or the streaks and bands and all I got was a pixelated bird. Thus, I am unsure if this has got to do with the megapixels or the focus length.

By the way, is the focus length the same as the zoom length and how many times zoom does a 300mm lens give ???

Geoff Chandler
08-06-2005, 03:21 PM
Make that 1/4 the pixels for doubling the zoom - the picture elements are length x width so halving them means a quarter of the total number. But I've printed many good plain paper pics from my 2 MP Canon snapshooter (775).
Ok - I can see the logic in that - BUT I recently took 2 near identical shots.
1) with the C-740 at 3,2mp at 380mm
2) with the A-200 at 8.0mp at 200mm - with 2xdigital as well

The upshot is the A-200 pic pixalates noticably LESS than the c-740 pic
(If you like I could create a couple of comparison pics, ie paste then together)
I know that the image from the A-200 is slightly closer so tat would contribut a tad.

Rob vdKam
08-08-2005, 06:14 AM
Thanks a lot for your tip. I am refering picture quality as in focus because I do not seem to get the kind of image most people have taken in comparison with my pictures.

My main use for my camera is to take pictures of birds which require minute details for identification, so I tried many times with different ISO, Shutter speed, aperture, white balance but still could not get the clear detailed pictures.

For e.g. I saw a bird at 50m away. At full zoom, 12x, I took a shot. I could see the outline of the bird and the shape of it which helps when seperating different groups of birds like differentiating eagle from sparrow. However, I was unable to capture the original colors or the streaks and bands and all I got was a pixelated bird. Thus, I am unsure if this has got to do with the megapixels or the focus length.

By the way, is the focus length the same as the zoom length and how many times zoom does a 300mm lens give ???

Was the bird pixelated but not the rest of the image? What about objects around the bird? If everything in the image was pixelated, you may have just zoomed into the image too far to try to see the bird after you took the picture. If not, I believe I've read that it is very very difficult to shoot birds with anything except a SLR.

Yes, focal length is related to zoom, but every camera has a different calculation unless they have the same CCD size. I don't know how it works well enought to explain it but others have done so in these forums. Try a search of zoom or something like that if you want the details.

Rob vdKam
08-08-2005, 06:22 AM
Ok - I can see the logic in that - BUT I recently took 2 near identical shots.
1) with the C-740 at 3,2mp at 380mm
2) with the A-200 at 8.0mp at 200mm - with 2xdigital as well

The upshot is the A-200 pic pixalates noticably LESS than the c-740 pic
(If you like I could create a couple of comparison pics, ie paste then together)
I know that the image from the A-200 is slightly closer so tat would contribut a tad.

Interesting. This weekend I took shots of a far away stone wall using the Sony H1 and the A200. The H1 was at 5MP and 12x optical plus 2xdigital. The A200 was at 8MP and 7x optical plus 2x digital. At least I think that's what the settings were. In any case, I found the A200 pixelated more when viewing the images at the same scale. I probably have the numbers wrong though, and I didn't have the two cameras side by side, so let me stress that it's just an impression that the Sony performed very well in this case.

I assume your results were expected due to the number of pixels. We've finally made up our mind to get the A200 over the Sony due to the viewfinder quality. There are just too many times that we can't see the subject in the H1 viewfinder. Makes the camera a pretty good paperweight in those cases.

Geoff Chandler
08-08-2005, 03:50 PM
Can't comment on your comparisons much - would need to know the 35mm equiv focal lengths
These are two crops from the two cameras C-740 at 380 and KM-A200 at 200 with 2x digital - I think you'll have to magnify them yourself.
Anyway - I don't think you'll regret choosing the A-200. No you won't get everything perfect and right straight away, it's a good learning camera that's pretty easy to learn your way around.
Please feel free to ask any questions - either here or via e-mail
Geoff

Geoff Chandler
08-08-2005, 03:51 PM
The original shots side by side (obviously reduced)

bhbrown8
08-09-2005, 03:54 PM
[WROTE]: "Ok - I can see the logic in that - BUT I recently took 2 near identical shots.
1) with the C-740 at 3,2mp at 380mm
2) with the A-200 at 8.0mp at 200mm - with 2xdigital as well
The upshot is the A-200 pic pixalates noticably LESS than the c-740 pic
(If you like I could create a couple of comparison pics, ie paste then together)
I know that the image from the A-200 is slightly closer so tat would contribut a tad."



i came across this forum and was just wondering if you questioned whether your problem is a technical one rather than a photographical one. (haha, i probably said this wrong)... anyway, i've noticed that not every digital camera outputs the DPI (dots per inch; or resolution) of its file the same as another. For instance, my camera outputs at 72 DPI (which is what most are). It's a 6 (roughly) MP camera, so the picture size is huge (like 30 by 40 or something), but again, only 72 DPI. I always going in an change this in Photoshop before I print mine. A buddy of mine has a Sony and it outputs the files at 300 DPI (I think), which is a much higher and better quality for printing... therefore, less pixelation. So that's a possibility.

Another thing of concern, are you viewing your pictures in print or on the computer? Again, depending on how your camera outputs the file, your computer may interpret it differently than another file. For example, have you ever taken a picture of telephone wires and then viewed them on the computer? Sometimes they look all broken, distorted, and pixelated. The file doesn't fit right to the screen size.

And my last comment is about digital zoom. In my opinion, digital zoom sucks. It's an interpretive zoom, not a true zoom, like optical zoom is. It's way cheaper than optical zoom, so of course many camera come standard w/ it and they talk it up like it's something great. Digital zoom will add to the pixelation of your image, so be careful w/ that.

I hope that this bit of information helped anybody here that was having problems. Let me know if you have any questions, comments, or concerns. Again, I just stumbled on this forum, but i'll try and stop back.


bhbrown8

Within
08-11-2005, 04:50 AM
Thanks Geoff for your pics. It had answered my queries.

Brown, I agree with you that digital zoom sucks. It has more disadvantages over advantages that I cannot bothered to use it.

If anybody can find a good use for digital zoom, I would be glad to hear it. By the way, does resizing and cropping have any differences?

harishkumar09
02-20-2007, 04:49 AM
Let me tell you just dont get fooled by MPs.Color reproduction is very important.Canon and Nikon are really the best in this game but Nikon is costlier.A 4 MP canon gives superior prints compared to a 6 MP Sony which does not have good color reproduction.You need to take evrything into consideration.

Graystar
02-25-2007, 08:31 PM
How many megapixels do you need? 10.

With 10 megapixels you can print at 200 dpi and produce an 18.24" x 13.68" print with no pixelation...which you can have done at your local Staples for Office Depot for about 10 bucks. That should fit the needs of a very large majority of people.
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sla
02-26-2007, 12:23 AM
I think nowadays you needn't look at sensor pixel number of the camera. Cameras with less than 5MP are rarely produced. This is usually more than enough for even quite large prints. And lens quality, image sensor quality and image processor are more important than sensor pixel count.
But if you are really concerned about numbers, take a look at the 2 tests: canon A620 (http://www.digitalcamerainfo.com/content/Canon-PowerShot-A620-Digital-Camera-Review-/Testing--Performance.htm)
and Fujifilm F31 (http://www.digitalcamerainfo.com/content/Fujifilm-FinePix-F31fd-Digital-Camera-Review/Testing--Performance.htm) tests, "resolution and sharpness" chapter.
Canon is 7mega, Fuji 6mega. But Fuji seems to have significantly better resolution.
BUT it doesn't mean that Fuji is better. Compare colour accuracy tests, noise tests and other tests. Now the choice is not so obvious.
regards
s.

mythuat24h
11-26-2013, 07:55 AM
I have a canon eos 1100d with 12 mp and it is good for me.