Hot answers tagged megapixels
25
From a purely theoretical point of view: more megapixels good.
People often talk about how high megapixel sensors were now outresolving most lenses, thus there was no point going higher unless using the very best glass. This is not always true. System resolution is the product of lens resolution and sensor resolution. Thus if you improve one, your system ...
25
I think Film vs Digital article by Roger N. Clark answers exactly this question. Let me quote the chart from its summary:
The main point is that digital sensors have fixed resolutions and variable sensitivity, while films have fixed sensitivity and varied resolution. Overall, at high ISO (> 400) most of the modern sensors provide higher resolution, and to ...
21
Downscaling a larger image on computer is almost certainly going to produce a better result. This is because resizing an image is very processor intensive, and there is a difference in quality between the various resampling algorithms (e.g. Lanczos vs Bicubic). Getting a 5 MP camera to produce a 2 MP image is going to cause the camera to perform the resizing ...
20
Pocket cameras have significantly smaller sensors than DSLRs, usually in the range of 5mm across as opposed to 22mm across. I'm not familiar with the Olympus mu range however I've seen 12 and 14 megapixel compacts.
These have more megapixels than DSLRs produced a few years ago, however it is mostly done for marketing purposes. The lenses in pocket cameras ...
15
Philip has it spot on there, resampling on a computer will give you more control and access to better resampling algorithms.
There's another reason not to select a smaller size on camera and that is if you download your photos and find one that is really good you can keep it in high resolution. If you set your camera to 2 megapixels there's no going back!
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14
Yes - if you took the same shot using the same lens on two cameras, one with 6 megapixels and one with 12, you would be able to crop the larger image, effectively zooming into the image.
There are a few things to bear in mind:
12 megapixels is not twice the size of 6 megapixels - it's only 41% bigger along each side.
The image quality at the pixel level ...
13
That means 22.5% more pixels in each direction.
5196 x 3464 instead of 4242 x 2828. (The megapixel value is of course rounded, so the exact resolution varies between cameras.)
If the cameras are otherwise comparable, you get more details with highter resolution. However, 12 megapixel is good enough for most uses. If you for example make 4" x 6" prints, you ...
12
The answer is "it depends". With some films, the limitation was the lens for all practical purposes, just as it is with the extreme-resolution DSLRs today. Kodak Technical Pan shot at ISO 16 (yes, 16) could easily resolve 150 line pairs per millimetre, which would give it a Nyquist equivalent of just under 80 MP in the 135 (35mm) format. Kodak's Ektar 25 ...
12
Noise originates due to a number of factors, see:
What types of noise can be present in digital photographs?
Increasing the number of megapixels keeping everything else constant (sensor size, technology etc.) will increase noise per pixel, but also has the effect of making the noise finer grained which is less objectionable.
ISO does not by itself ...
12
Sensor area doesn't determine resolution in the same way as the film era. Back then simply increasing the area of film would yield a similar increase in the size you could print, and therefore the detail you captured. In the digital world sensors can have different numbers of pixels per cm
Both 12MP compact and DSLR will resolve similar levels of detail ...
12
Megapixels are Necessary!
The megapixel race is certainly not "unnecessary". Consistently throughout the last decade, progress has been made on the megapixel front while consistently increasing image quality. The anecdotal adages would have you thinking that was impossible, but there are quite a few technological and fabrication improvements that have made ...
11
Facebook images are usually displayed at around 720×540 pixels. That is about one third of a megapixel, so for that use, anything you can buy is overkill in terms of megapixels. This is perfectly fine for almost all online display, and will even make decent small-sized prints.
However, megapixels do not accurately represent image quality. The answers to Why ...
11
If the resolution long axis is at least 1920 and the short edge at least 1080 then yes, you can take HD images without having to upscale.
However, due to benefits of oversampling, you will make a better HD image by grabbing a 16MP image and then resize with the best available resize method, e.g. lanczos interpolation if available.
Another problem you may ...
10
Megapixels are to cameras what top speed is to cars: it's an easy headline figure to boast about when in reality most customers will never need it. Worse still, other features may have been sacrificed in order to meet a price point with that alluring headline figure intact.
Put another way, it's a bit like asking why a little Hyundai has a top speed of ...
10
I have been using various Kodak E100 series slide films (100 ISO) in a Leica, with good optics, and the detailing that my Nikon Coolscan V gets out of these is absolutely absurd. I'd say about 20 megapixels' worth of detail, give or take - easily as good as my 16.7 mp 1Ds II anyway. Given a good exposure and focusing in the first place, of course. How this ...
9
The resolution, by itself, doesn't mean much. For a meaningful comparison, you need to look at one camera versus another, not one resolution figure compared to another.
Assuming you're talking about an APS-C sensor, 12 MP is high enough that the sensor resolution is only rarely the limiting factor on the resolution of the picture you get. In a typical case, ...
9
You are right that a 1080p HD image has just under 2 megapixels.
Now where you have to be careful is in considering the aspect ratio of your camera. If it shoots natively 16:9 images and it has 2 MP, then you would have enough resolution. If the camera has a 4:3 sensor which is the most common for small cameras, a 2 MP camera would most likely capture a ...
8
No. Because different films with the same ISO can have different quality aspects, and digital cameras with the same megapixel count can have different quality aspects. There are also many potential variables in processing/development and printing for both film and digital that will effect image quality.
You can discuss very specific examples. For ...
8
It probably doesn't matter very much.
The computer has an advantage because it can bring more processor power to bear. You can use more sophisticated algorithms, including tailoring the right one to each image. (And, as Matt Grum points out, you have the larger version available if you change your mind. This is probably the most compelling reason to go this ...
7
Storage/speed issues aside, having more megapixels is going to make absolutely every single picture you take better. Maybe only a little better in some cases, but that sounds like something worth having to me.
If you've ever had an image suffer from Moire (colour banding patterns):
Maze artefacts:
Aliasing:
Colour fringing, false detail, lack of ...
6
A different spin on the more megapixels question is not "is the edge to edge image clarity better" but "is there something I could do with the extra bits"? One thing I'm seeing more and more is the flexibility to repurpose images by cropping simply because a cropped image still has sufficient resolution for many, if not most, purposes.
And... if/when lenses ...
6
I remember seeing a figure of 22MP was "as good" as 35mm resolution (of course, with film it isn't just the ISO, but the manufacturer and age of the film, skill of developer etc.)
Higher ISO film tended to have more grain; and higher ISO digital shots exhibit more noise - a similar cause, but the visual appearance is different.
Digital ISO noise is related ...
6
The lens is in front of the sensor, so the sensor cannot get any more details than the lens lets through. That is why if your lens is of poor quality, your images appear blurry.
Now, it is never better to shoot at a lower resolution because the lens resolves a fixed amount of details in a given state (focal-length, aperture and focus-distance). At worst, ...
5
Conventional wisdom says about 6 MP at around IS0 200 when looking at overall image quality.
Although film works very differently then digital images, so some people point out that the finest film grain is much smaller than a pixel on a 6 megapixels DSLR. I suspect this is why someone told you 24. While it is can be true, one pixel captures way more ...
5
There are two reasons in my mind why you might care about more pixels, one of which might apply to the average photographer, and one that would apply mostly to pros:
Retouching. Pro photographers often use a medium format for the super critical mega dollar shoots. In these situations, a Phase One digiback (39 megapixels) or a Hasselblad (31 mp) or some ...
5
I would put the number of megapixels at the bottom of the priority list. Megapixels matter, but once you get past about 10 you'll have enough for anything you're likely to do. In particular there wont be a noticeable difference between 12 and 16, theoretically you'll be able to print a 16MP image 15% larger, but that's only if the lens resolves more detail ...
5
As @ahockley said, the resolution (number of megapixels) is determined primarily by the sensor, so changing the lens doesn't change it.
Being fair, the resolution of the sensor is basically the theoretical maximum of which the system as a whole is capable. Although a better lens can't increase it, a really poor quality lens could reduce the effective ...
5
No, because of the Bayer filter. You would actually need around 11 megapixels.
What a Bayer filter is
Colour camera sensors use Bayer filters to capture the various colours. The Bayer filter effectively halves the resolution of the sensor for each colour (though green is left with slightly more in a checker-board pattern).
Each pixel on the sensor can ...
4
It's not easy to compare ISO grade with sensor resolution because they're not related. What's more related is noise ratio versus film grain, but it's not that simple.
Film grain behaves differently that sensor noise. Where sensor noise makes you lose detail is where the noise limits the ability to perceive detail. Film has grains of different sizes and ...
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