Should you set your camera to take the biggest photo size possible? Are more pixels better? You know, I would like to think people are actually asking themselves these questions, but somehow I seriously doubt it. Call me weird. If you are, though, maybe my experience recently in answering these questions for myself might help you toward find the best answer for you. I have even made up some example photos to compare the different image quality settings.
My wife recently bought a point-and-shoot for family use–honestly, it is mainly for videos. When I was setting everything up for her, one of the decisions I made was NOT to use the highest image quality setting. Call me crazy. A few factors came into play: image quality, file size, and how big the photos might be printed.
I have already waxed on about the size of the sensor and how that affects image quality. What I still wondered was what the difference really was…I mean in real-life images. The settings I wanted to compare on our camera were the two 12 megapixel settings and the 6 megapixel setting (there is nothing in between). So, here you go:
Those are all separate photos taken at the same time, from a tripod, with the exact same settings (as best I could do so with a compact camera which chooses some settings for you). So, the only difference should be the image quality setting.
Can I see a difference? Sure. On this camera the actual file size of those photos is approximately 1.2MB, 2.8MB, and 4MB, though size varies from camera to camera and photo to photo. Those look like a small difference right now, but 1000 photos later, that is gigabytes worth of difference, and if they are family photos, they are probably all going to be sitting on our laptop so we can show people. So, what I see is this: I can save a lot of space on the computer for a very small difference in quality.
And as for printing, well, never would one of these photos be printed more than an 8×10 inch size, and six megapixels is more than enough for that. So, that is not a problem.
So, my choice (for the point-and-shoot, compact camera) is to just shoot the 6MP setting. What do you think of the quality difference in the images above?
The issue with megapixel size isn’t really one of quality per se… It is one of image data. In using more pixels, more data is recorded for that image. Then when you are applying effects, GIMPing, etc etc there is less degredation in visible quality as the computer has more data to work with when applying effects etc. (It also is lovely for cropping at a later stage!)
Printing is a slightly different story… An 8×10 at 300DPI (decent print quality) requires 7.2 MP ( (8*300)*(10*300)/1000000 = 7.2 ) and most current home inkjets will go well above that quality on decent paper and so better quality is easily aquirable (That’s ignoring pro-printing…) But the results need to be appreciated and the difference between a 6MP and 7.2MP will only really be discernable at very close inspection…
But yeah, it is worthwhile remembering though that in the early days of digital photography National Geographic photographers (I know of one for sure, but don’t remember his name!) were producing full spread photos on 3MP dslrs!
My personal choice has always been to shoot on high-res… When space is at a premium I will burn originals off onto DVDs and do a batch resize of keepers to a resolution that is fine for my laptop screen, presentations etc… I very rarely print photos to be honest…
I guess you have a point about the editing: the more pixels you have the more the editing software has to deal with. I did not really take that into account, because even with my SLR, I do not do that much editing. On top of that, this is just the compact camera. I do not foresee too much editing.
I really wonder about your comments about printing, though. 300DPI is standard in the printing industry, and going above that does not really help much does it? 300DPI is already really high. I don’t know. I am not the printing expert.
I think for my SLR, I still would want more megapixels than, but still, only to a certain point. At some point, it is excessive, depending on your needs. I could use more (I am thinking 12MP or so), but I think the new 24MP cameras are beyond what I would ever need. Well, maybe the files are not all that much bigger. My 6MP camera shoots 10MB raw files, and several 12MP cameras also save files just a little bigger than that! So, it might not have many bad effects.
On second look I think you are right, I was basing my thoughts on printing outputs, but I think the printed DPI needs to be much higher than the photo’s PixelsPI as each dot can only really be one of however many ink colours the printer has… where a pixel can be one of millions of colours… so there needs to be a bunch of dots to each pixel to give the desired effect…
But then 8×10 still needs 7.2MP to give an actual 300 DPI photo…
To be honest I’m not too bothered… like I said the results always still need to be appreciated, and I doubt my eye is discernable enough…
I’m happy with my old canon’s 6MP, sometimes more would be nice for a crop of a hastily taken shot, but its just a bit of fun really!!
My D100 is a 6MP camera as well, and it has proved a great camera. I rarely make such a radical crop that the extra megapixels would really help in that way. If I crop, I just crop a little of the edges. The extra megapixels would only be nice to print a little bigger at 300dpi.