Do I need the megapixels?

Discuss cameras, settings, composition, or anything related to photography - cactus or other subjects.
DaveW
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Do I need the megapixels?

Post by DaveW »

I bought a new digital WXGA projector at Christmas and just used a Web megapixel calculator to find out the resolution of my 1280 x 800 new projector and it equals 1 megapixel! How much overkill is a 10 megapixel camera image then!

http://web.forret.com/tools/megapixel.asp" onclick="window.open(this.href);return false;

A friend of mine said he projected some images from a 4 megapixel point and shoot among those from his multi-megapixel high end Nikon and nobody could tell the difference on screen. In fact the quality of the camera lens, such as good image contrast and lack of distortion will make more difference to projected images than extra megapixels in the camera. High camera megapixel numbers are only of use if you make large prints or crop heavily.

http://www.kenrockwell.com/tech/digital ... r-myth.htm" onclick="window.open(this.href);return false;

Checking my computer screen at it's native resolution of 1920 x 1200 pixels only gives it a resolution of 2.3 megapixels.

Still prefer to see the brighter new digital images on screen to the old film slides though!
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Harriet
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Re: Do I need the megapixels?

Post by Harriet »

I know the mega pixels are over kill, but as you say, they are much preferable to the old film slides on-screen. I think it is a bells and whistles thing with me, if you offer me a choice of cars, I will generally take the one with more power...Zoom zoom!
It’s not the fall that kills you; it’s the sudden stop at the end.
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SnowFella
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Re: Do I need the megapixels?

Post by SnowFella »

Can't really say much as I just went from 14.2 to 24.3 megapixel 8-[
Now I do know it's not going to be needed in 99% of cases but it's going to allow me to crop much closer than what I have been in the past. I shoot plenty of birds and small things while out on my walks and with the old camera I could never really crop in as close as I wanted. More resolution will allow me to crop in more in those cases when the lens I'm carrying just won't let me get close enough.
DaveW
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Re: Do I need the megapixels?

Post by DaveW »

Trouble with megapixels and resolution improvements is it is an area not a linear thing. To get the same image improvement as from a 2 megapixel camera to a 4 megapixel one it is not another 2 megapixels, but an 8 megapixel camera. Therefore to get the same degree of image improvement every new camera we buy we would need to go 2-4-8-16-32-64-128 megapixels and it is obvious the manufacturers do not bring out cameras in that sequence, therefore the degree of image improvement has slowed down on every new camera model they introduce.

http://www.luminous-landscape.com/essay ... sign.shtml" onclick="window.open(this.href);return false;

What can increase however if they keep the sensor size the same but keep increasing megapixels is image noise, since the pixel sites become smaller and noise reduction software usually degrades resolution by making the image softer.

http://www.trustedreviews.com/opinions/ ... ion_Page-2" onclick="window.open(this.href);return false;

Regarding cropping that does not always produce as good an image as getting it full size on the sensor using the correct focal length lens. A quote from the following link:-

"Sometimes photographers only want to print part of a photo. So they might start with a 12-megapixel picture, chop off half of it (crop it) and they’re left with 6 megapixels, which will still have enough resolution to print a nice A4 image.

Of course, that’s assuming their photographic equipment and technique was pretty good, because if there’s any motion blur or some other fault in the original photo, then it’s suddenly going to be a whole lot more noticeable after they’ve cropped the image and filled the page (or screen) with whatever they have left."


http://www.mdavid.com.au/photography/megapixels.shtml" onclick="window.open(this.href);return false;

http://snapsort.com/learn/sensor/true-resolution" onclick="window.open(this.href);return false;

http://www.digitaltrends.com/photograph ... e-matters/" onclick="window.open(this.href);return false;
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SnowFella
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Re: Do I need the megapixels?

Post by SnowFella »

True, but if I can now throw away 10 megapixels worth of information and still retain the same amount of info I had before it's a win/win situation for me aslong as I've nailed focus and shutter speed for a crisp result.

And does indeed come with it's drawbacks, a big one would be file size and how quickly you fill up a card/buffer. Now I've yet to buy myself a really fast SD card and will make do with class 10 SDHC cards untill I can afford something faster and clearing the buffer if I go nuts with the cameras highest framerate takes ages. Just a seconds worth of holding down the button if I'm set at highest FPS and I'm looking at 10 or more seconds before I can snap another photo.
Not really that important in my case though as it will be set for single or low FPS in most situations, can't see many reasons to go nuts with 12 shots/second.
DaveW
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Re: Do I need the megapixels?

Post by DaveW »

The point to remember with photography is to always fill the frame if possible and crop as little as possible later. From film days to digital the less the original image on film or sensor is enlarged the better the quality because enlargement always magnifies any flaws in the image, no matter how many pixels you have. In the days of film enlargement increased the film grain therefore small format images enlarged to the same final size were never as good as from larger format cameras. Similarly images from smaller sensors which have to be enlarged more are never potentially as good as from larger ones, no matter how many megapixels the small one has, for the reason image noise and other image faults are enlarged much more. That applies to cropping too, which is in effect reducing the original sensor image to that of using a smaller sensor, so it needs to be enlarged more later.

http://www.twoeyesonnature.com/tag/over-cropping/" onclick="window.open(this.href);return false;

Say by using the correct focal length lens you filled your sensor with a bird that required no further cropping and then compared it with a crop of the same bird taken on a shorter focal length lens where half the image would need to be cropped away. The second image would need to be enlarged twice as much in the final print to match the size of the first. What would also be enlarged twice as much is any noise on the sensor (and more megapixels on the same size sensor always produce more noise) plus you enlarge the circle of confusion twice as much so it may become detectable to the human eye and depth of field may not appear as great.

http://dbp-consulting.com/Photography/C ... usion.html" onclick="window.open(this.href);return false;

As said cropping the sensor image is just like taking the image full frame on a smaller sensor which then needs to be enlarged much more for the final image. This following link compares a Nikon D200 APS-C sensor image enlarged to match that of a Canon full frame image. The Canon would produce similar results if it's original image was taken the same size as the Nikon then cropped to the same size as the smaller sensor and then enlarged:-

http://www.kenrockwell.com/tech/full-fr ... antage.htm" onclick="window.open(this.href);return false;

This link is a little bit dated now but has relevance to your bird photography:-

http://www.digitalbirdphotography.com/2.3.html" onclick="window.open(this.href);return false;

Of course all this only matters if the human eye can detect it in the final image, but since a computer screen has a resolution of less than a 4 megapixel camera 20 of your new megapixels would already have been binned when you post online, as would 10 of your previous cameras, therefore the screen image of a cropped bird would show no increased resolution to your previous 14 megapixel camera even if similarly cropped, or even from a full frame image from an 4 megapixel camera, since only a very large print would show any difference. As they say "a chain is only as strong as it's weakest link" and in our cases unless we print house door sized prints it is the computer screen or digital projector that limits us.

Newer cameras have many advantages and improvements which are worth having, but mere pixel numbers is no longer the most important. In fact some claim many are now over pixelled for best image quality. If you want more significant extra megapixels you really need to step up to larger sensors, full frame or even medium format. However given the choice we all still buy more pixels than our type of photography needs, but in truth better lenses of the right focal length to reduce the need for cropping will do more for our photography than more pixels.

Enjoy your new camera anyway, the new features will be worthwhile and helpful but don't expect to see much difference in the image onscreen, only in any large prints you make.

Since you are also into bird photography you may be interested in this series:-

http://www.digitalbirdphotography.com/2.1.html" onclick="window.open(this.href);return false;
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SnowFella
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Re: Do I need the megapixels?

Post by SnowFella »

True, getting a proper composition will beat crop every day of the week although in some situations it just isn't possible. Case in point would be my last little outing, first with the camera, where the longest lens I had with me was a 100-200mm and having the wife's favourite bird nicely perched just a tad out of reach with that lens I still shot a fair few photos with the intent to crop in once at home.

Original as out of the camera came to this, just jpg downscaled to 1024x683
Image

Bit of Lightroom massage of the RAW later and some crop and it's passable to have printed for her, cropped it's still a decent 4000x2667.
Image

Near grey bird on greyish background really messed with the exposure but it was mostly recoverable from the RAW file. Later shots in the series were better exposed as I started playing with exposure compensation but I just never got the same pose out of the bird again.
Also faced the same "problem" when trying to shoot mangrove crabs on the same day, was just no way of getting close enough to frame properly without the little buggers running for their holes long before I was close enough.
Sure I could of brought my 75-300 lens along or perhaps used the 70-210 with 1.7xTC but the 100-200 is just sooo much more portable a package when there's hours of walking to do. Can probably tell why from this ;)

Image

Acctually giving me alittle bit of a headache when it comes to packing for my week long holiday, sure I'm driving so weight isn't really an issue but overall bulk is. Didn't have that "problem" last time I went to this place as all I had back then was camera and 2 kit lenses. Now there's way to much to just fit in my backpack camera bag plus a decent tripod to haul along. :oops:

Btw: thanks for that link, been busy reading away this afternoon and there's some good tips there indeed. Though as a Sony shoooter he's alittle biased against it :lol:
DaveW
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Re: Do I need the megapixels?

Post by DaveW »

I suppose it's just really about lenses for him picking Canon and Nikon, rather than the cameras themselves. Most cameras have all the lenses the average photographers need, it's only when you get to ultra specialist photography like extreme macro equipment, or those needing ultra telephoto's like birds etc where only the "big two" normally provide the extreme lenses the others do not.

As I said previously, what you need really depends on the final method of reproduction. If it's for Web use then high megapixeled cameras will be reduced to the same resolution on screen as a low megapixeled one, so are no advantage even if able to theoretically crop more if you are printing or produce bigger prints. The only fields that need the extra megapixels are book illustration and the conventional printing industry, or producing very large photographic prints.

In my early film days I could never understand why the natural history programs on TV could get so much more depth of field than I could, until a program finally explained that it was the comparatively low resolution of the TV image. In the higher resolution photo slides or prints at that time the ultra sharp in focus parts stood out against the less in focus ones more distinctly to the human eye. However the lower resolution TV image, being more blurry to put it simplistically, masks the difference between the ultra sharp in focus parts and those a little more fuzzy so they both look equally sharp on screen, apparently giving more depth of field.

That means we can get away with smaller apertures that are subject to some diffraction degradation on screen which would be obvious on a higher resolution print. It also means that pictures from a lower resolution camera will look no different to a higher resolution one on screen, but would if printed out in a large print. You have to ask yourself how often do most people print out or sell their pictures these days, as against those who only want to post electronically or use on things like smartphones? This is probably why most people are now considering smartphone images are good enough for their purposes and the conventional digital camera is going into decline.

http://www.steves-digicams.com/news/dig ... blame.html" onclick="window.open(this.href);return false;

Probably we and the photographic sites are the "Canute's" trying to hold back the waves of smartphones overwhelming our type of cameras.
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SnowFella
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Re: Do I need the megapixels?

Post by SnowFella »

Yup, it's amazing how many people that get by with their smartphones. But for only taking photos to upload on facebook and the like they are perfectly alright.
Bought the wife a decent little Olympus point and shoot a few years back that is not much larger than her phone but she still relents on using the camera on her Iphone, mere 3 megapixel sensor on that one.

As for printing, I'm hopeless when it comes to that and it's been years since I printed a single shot.....untill today when I got that pelican photo printed up at 10x8 for the wife. Last time before that must of been an old wedding photo of the stepson and daughter inlaw that I took at their wedding 7 odd years ago. Somewhat cropped from a 5mp bridge camera but still plenty enough resolution to blow up on a 18x12 canvas, the canvas itself likely hid enough lack in resolution and noice to make it look decent though.
A. Dean Stock
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Re: Do I need the megapixels?

Post by A. Dean Stock »

Intersting discussion and well worth thinking about. More pixels are not always worth moving to a new camera but I've long been aware that if you are publishing an image in a journal, pixels do make a difference. Just how far you need to go with that to reach diminishing returns remains unknown to me but I have noted that editors like my 18 megapixel photos better than the 10 megapixel ones, all other things being equal.
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DaveW
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Re: Do I need the megapixels?

Post by DaveW »

And yet in the past publications like National Geographic were making double page spreads with far lower Megapixeled cameras since that was all the professionals had in those days.

Maybe in the future they will not accept images from APS-C cameras but only "full frame" ones? I remember years ago reading some publications turned their noses up at 35mm slides demanding medium format Hasselblad type images. So one enterprising pro duped his 35mm slides onto sheet film, blowing them up to medium format size and the publications then accepted them as the quality they required. A lot of professional snobbery often involved where some claim they can tell the difference but would not be able to in a proper blind scientific test, just relying on the image size for the clue it was medium format.
A. Dean Stock
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Re: Do I need the megapixels?

Post by A. Dean Stock »

Yes, but National Geographic published mainly scenes and large images of people not chromosomes or details of smaller subjects. In the long view, pixels are probably not as important as lighting, focus, etc, but I do see more detail in chromosomes photographed with a 10 megapixel camera compared to those taken with a 4 megapixel camera using the same basic lighting and setup. I think that I also see more detail in higher pixel photos of cactus blooms vs those with a pixel level of say 4 megapixel or lower. How higher pixel ratings like 18 or 20, etc. boost details in smaller subjects may be debated, but in the end, how the image is printed or viewed makes the real difference.
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DaveW
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Re: Do I need the megapixels?

Post by DaveW »

Really what you want is the largest pixel site size for a given number of megapixels on any camera. Simply increasing the number of pixels on the same sized sensor by reducing the pixel site size can in fact degrade the image since it produces more noise. That is the reason the camera manufacturers have now largely given up increasing the number of megapixels on the APS-C sensor and moved to the same or more megapixels on full frame cameras instead as being the way forward.

http://www.digital-photography-workflow ... ixels.html" onclick="window.open(this.href);return false;

How many megapixels do you really need for publication?

http://www.mdavid.com.au/photography/megapixels.shtml" onclick="window.open(this.href);return false;

In fact when they introduce more megapixels manufacturers often have to increase the noise suppression, which simply means softening the image so it is less sharp. Also always shooting as far as possible at the base ISO of the camera makes a big difference to picture quality. I never shoot at above ISO 100 on my camera if I can avoid it. High ISO's are for taking "black cats in coal cellars", or images where any image will do and image quality does not matter.

https://photographylife.com/the-benefit ... ion-sensor" onclick="window.open(this.href);return false;

Also you will never get the maximum resolution from your camera hand holding it since camera shake occurs at any shutter speed. Fast shutter speeds simply show less shake on the image and a camera on a tripod shows the least of all, hence produces the sharpest image.

As to 4 versus 10 megapixels, it has to be remembered megapixel values on a sensor are an area not a linear thing. Therefore simply stepping up say 2 megapixels each new camera will not produce the same increase in image quality at each new step. To gain the same image quality increase with each new camera the manufacturers would need to go 4-8-16-32-64 megapixels, a doubling series, which is why camera image quality is not increasing at the rate it did in the past when they went from 4 to 8 megapixels A 24 to 28 megapixel step would scarcely be detectable with regard to increase in image quality, but the step from 4 to 8 megapixels was significant.
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SnowFella
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Re: Do I need the megapixels?

Post by SnowFella »

Well, not 100% can be attributed to just bigger megapixels but you would also have to factor in sensor generation. The higher mp cameras are generally newer and newer sensor tech has done wonders for image quality. Plus it's also a fallacy in the way people look at photos on their computer and complain about noise, at 100% magnification even a perfect shot will have noise but viewed at a sensible scale will look nice and clean.
Can't say I agree with anything this bloke says but most make sense to me.
https://youtu.be/_KYvp8PrCFc

Just spent a day up the mountains hunting little feathered things with a long lens and if I had stuck to base ISO not many shots would of been keepers. Especially the Lyrebird shots I got way into undergrowth. Even at ISO3200 I was down at 1/125sec, results are still decent with a little massage in Lightroom for noise and sharpening.

One of these days I have to do a comparison between the 3 APS-C cameras I have kicking about, (14, 16 and 24mp all with the same lensmount) and 3 different generations of sensor tech to see if I can pick up a difference. I'd hazard a guess the 16mp will come out ahead, closely followed by the 24mp and the 14mp will lag behind. Though the 14mp body will have a leg up due to it's design, it's a classic SLR design while the other 2 are SLT, mirror on the SLT's stay down and steals ~1/3 stop of light forcing compensation to get the same brightness in a shot.
DaveW
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Re: Do I need the megapixels?

Post by DaveW »

Have not had time to watch all your link yet. However if we go back to film, given the same emulsion coating the same sized print from a 35mm camera will be more grainy than that from a medium format one simply because we have enlarged the original image and all the grain and faults in it more for the same sized print. The same also occurs with digital, if you enlarge the image from a small sensor, given the same noise at that ISO, this and any aberrations of the lens are enlarged more than from a full frame sensor, so the same degree of noise on both sensors would become more apparent on the one enlarged the most for the final print.

As to ISO, increasing the ISO on a digital camera merely increases the gain on the sensor as I understand it, making noise present on all sensors more visible?

https://photographylife.com/what-is-iso-in-photography" onclick="window.open(this.href);return false;

http://www.digital-slr-guide.com/iso-an ... noise.html" onclick="window.open(this.href);return false;

The problem with hand holding and ISO is that at low ISO for better quality images you are more likely to have camera shake softening the image, whereas if you need to use high ISO's to avoid it noise will become more of a problem and noise reduction simply blurs and softens the image also.

http://www.techhive.com/article/2025509 ... hotos.html" onclick="window.open(this.href);return false;

Noise reduction is never as good as lower levels of noise at low ISO's to start with:-

http://www.colormancer.com/whitepapers/ ... ersus.html" onclick="window.open(this.href);return false;

However for web use rather than printing large prints the difference may be undetectable. As they used to say "though you can tell the difference in laboratory tests, if you cannot see it in day to day photography don't worry about it."!
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