Does SIZE really matter???

[Madison]

It matters depending on what your needs are.


If you want to produce higher quality museum or gallery prints at of certain dimensions: lower pixel counts will make that impossible.


If you want to publish in certain books: lower pixel counts will make that impossible (art books require different resolutions than magazines and newspapers require even less).


If I want to publish a huge print for a fashion ad: megapixels is a must. You end up without details and with pixellated images if you dont have enough image data to print at that size.








There is no right or wrong answer: it depends on you, your needs, and what your clients (if you have them) or gallery wants from you. So the one thing to do is ask YOURSELF what you need and what people need from your photography and then act accordingly.

[Brendan7]

Megapixels are a sort of statistic that companies use to sell their products. An uneducated buyer for, say, a point and shoot would often just pick the camera with the most megapixels, believing that's the most important statistic (I used to be one of those people, five years ago hehe). Really, as long as the pixel count isn't too low (5mp) or too high (20mp on 1.6, 32mp on FF?) it really doesn't matter.


I have a 7D, and I do appreciate its 18 megapixels because I can take an horizontal image, crop it into a vertical image and then some, and then go make beautiful 16x20 prints. As I can't afford/justify/deserve getting a 500 f/4, and shoot birds, the megapixel advantage of the 7D is very nice. Since in bird photography the pixel density is very important, a high-megapixel camera was good for me. Some need megapixels, some don't. Some want it, some don't.


My 2¢.


brendan

[Daniel Browning]

just wanted to know how you guys feel about "mega pixels".

I'm not ususally very in touch with my feelings, but since you asked about it, I guess I'd have to say that megapixels make me feel happy, interested, and slightly excited. []

There is this site that says that somehow a 6mp dslr is as good as any dslr including the high end 20+ mps bodies we have now.

It's nonsense. (Reminds of something that KR would say.) In reality, it's not even theoretically possible to get worse results from a 20 MP body than a 6 MP body, even in the hands of the worst photographer ever. The results will always be at least slightly better (at least in noise and color depth), and usually much better (resolution and contrast).

and that we the "ordinary" person [ read as non profesional] don't need to go and buy a high megapixel camera. As doing so would just be somehow wasting money.

Paying for something you don't need and never use is obviously a waste. So if you bought a more expensive camera *only* because of the higher pixel count, but never utilized the benefit of that pixel count, then obviously it would be a waste of money. But there are two points about that:

• There are many reasons to buy a new camera, getting more MP is often just a side benefit.
• Most people, even non-professionals, *do* benefit from 20+ MP

Even the most casual user can benefit from over 20 MP by getting better results from cropping ("digital zoom").

what do you guys think???

Pixel count is a good thing, and you can never have too much of a good thing. []

[Daniel Browning]

cramming more pixels into the same-sized sensor means that pixels are actually getting smaller and thus capturing less light, resulting in noisy images but I'm sure this is debatable.

That's a popular urban myth. The total amount of light captured remains the same with smaller pixels, as explained here:

Myth busted: smaller pixels have more noise

on cropped bodies I almost think a higher MP is a BAD thing... but 6MP is pushing it. I'd say that 12MP is a good number.

I disagree. In general, there is no downside whatsoever to higher MP. They have the same noise, dynamic range, color depth, diffraction, camera shake, etc. See the thread above for more information on how and why.

They would even have the same file size and processing speed if camera manufacturers used the right software. (Right now, some of them use flawed software, such as Canon's sRAW.)

Above that, you really need to be doing major studio or large print stuff... commercial stuff... for it to matter.

I don't think so. I think people generally underestimate the utility of higher pixel counts. Many people feel that 2 MP makes a very nice 8x10 print. Others think that anything over 6 MP makes no difference in an 8x10. But when I went from 13 MP (5D) to 21 MP (5D2), I noticed a huge improvement in contrast and resolution in my 8x10 prints.

There are basically two different points of view:

• What's the smallest pixel count I can use before the results are too hideous?
• What's the largest pixel count I can use before more pixels make no improvement?

If you look at it from the second point of view, there are many factors that affect the utility of the pixel count. For example:

• 10.4MP: Say you are doing an 8x10 print, and your printer/paper combination is capable of a maximum resolution of 360 ppi. That requires only 10.4 MP.
• 12.4MP: But don't forget that 8x10 is a different aspect ratio than 3:2 DSLR sensors. In order to have 10.4 MP after cropping off the sides, you need to start with 12.4 MP.
• 13.2 MP: Let's say that your DSLR does not have a 100% viewfinder because you can't afford a $5,000 DSLR. Instead, you have to crop the picture in post by 3% on two sides to match what you saw in post. This requires starting with a little more MP.
• 16.0 MP: Let's say that in addition to the viewfinder accuracy, you think of an alternate composition for the photograph only once you get it into post processing. It would have been better to take the alternate composition at the time of the photograph, but having the flexibility to do it later is a valid benefit of increased pixel counts. We'll say that you crop just 10% from each side. To do that and still get the 13.2 MP needed requires starting with 16 MP. I know that some photographers never make mistakes like this, but personally, I find myself cropping even *more* than 10% sometimes, only because I thought of a new composition that I did not realize at the time (or I didn't have the right lens/zoom with me).
• 27.0 MP: The optical low pass filter in DSLRS reduces contrast significantly. In order to negate the majority of this effect, it's necessary to have about 30% higher linear resolution: 27 MP! This is one reason why I noticed such a huge improvement with the 21 MP of the 5D2, even for 8x10 print sizes.

So in the above example, I showed that 27 MP would be the maximum useful pixel count for an 8x10 in circumstances that are common for me. On the other hand, if your printer/paper is only capable of 250 ppi, and you have a 100% viewfinder, and you never crop even 1% in post, then you would get the maximum benefit possible from only 10.1 MP (using only the above factors -- there are actually more, but they are less important). On the other hand, if you print 16x20 with the same factors as above, you're looking at over 108 MP for the optimum. So even with 21 MP, I still need to use stitching to get the optimal resolution for my photography.

All this is described in more detail in this thread:

What is the ideal number of megapixels?

I was using my 50D for a while and then I upgraded to a 7D. My 50D I still own, just a "second camera" but yet I feel it has less noise.

Your entitled to your feelings, of course, but the fact is that the 7D has far less noise in low light than the 50D.

Why? Because of the smaller sensor.

I think you meant "smaller pixel count", right? Or maybe "smaller pixel size"? They both have the same sensor size.

Sheesh, my Rebel XSi was pretty nice when it comes to noise!

The XSi and 50D have the same noise level in low light.

Really, as long as the pixel count isn't too low (5mp) or too high (20mp on 1.6, 32mp on FF?) it really doesn't matter.

Today's 2 micron pixels are proven to have about the same performance as DSLR-sized pixels (~6.4 microns) in many common circumstances. That would mean 216 MP in FF and 84 MP in APS-C. Anything above that may be too high for most circumstances.

[Jon Ruyle]

I disagree. In general, there is no downside whatsoever to higher MP.

I agree with the spirit of what you're saying, Daniel, but isn't it true that mp count may limit frame rate? For example, don't you think 1D cameras would probably be designed with higher mp counts if not for concern about frame rate? Don't you think the 5DII would have had a higher frame rate if it was 12mp?


I think pretty soon data rates will be so high that other factors limit frame rate and mp will no longer be a factor. But I think now, and for a little while longer at least, it is.

[Eric Smith]

Here is the print designer's perspective:


In offset printing there is something called "line screen" that has to do with the quality of the printing and it is based on papers used, etc. Low end printing would be something like newsprint. The line screen may be 80-120, probably on the high end. Your typical magazine may be about 133. A car brochure may be about 150, and a finely printed art book may run 200.


Images ideally should have a resolution that is about twice line screen, but can be as low as 1.5x.


Images that bleed off the page need 1/8" on each side that bleeds, so that can mean an extra 1/4" in height and width.


To keep things nice and safe, let's count on needing 300 pixels per inch. That gives us a full twice line screen for up to 150 line screen printing and 1.5x for that art book.


Divide your pixel dimensions by 300 and that gives your print dimensions. Don't forget the 1/4" that gets trimmed away in a full bleed.


This means the $900 T2i at 5184x3456 can cover a full bleed, twice line screen, tabloid sized spread the next time Mercedes wants you to shoot for their car brochure.

[Daniel Browning]

I agree with the spirit of what you're saying, Daniel, but isn't it true that mp count may limit frame rate?

Yes. That's a good point. I stand corrected.

For example, don't you think 1D cameras would probably be designed with higher mp counts if not for concern about frame rate? Don't you think the 5DII would have had a higher frame rate if it was 12mp?

You're right.


Someday, they might figure out a way to do on-chip binning with Bayer CFA sensors that doesn't have artifact issues -- then the high pixel counts will be able to hit the same frame rates as the low ones.

[Dallasphotog]

I can only add that I produce a lot of prints in the 8x10 to 16x20 range for customers and the difference from my 1dMKII to my 5dMKII is quite obvious to even the casual observer.


All the pictures onmy walls are now fromthe 5DMKII.


Additionally, when workingprofessionally with images for the company calendar, our artdirector can tell the differencein images off the 5DMKII and the 1DsMKIII. The5DMKII has become our "body of choice" for important work. I think the combination of resolution, image processor and sensor size does make a difference in ultimate image quality and that doesn't even begin to account for the huge cropping you can do with 22 megapixels.