??MP, how much do you need / use?
Discussion
Is 3mp enough or do you need 6mp+?
If you have an 8mp camera, do you have it set on it's highest setting?
If not what size do you normally shoot pics?
Just thinking that unless you are a pro, use Photoshop extensively or print large images, most people would get away with using a 3mp or less camera. Especially if you normally save / use the images on computer.
If you have an 8mp camera, do you have it set on it's highest setting?
If not what size do you normally shoot pics?
Just thinking that unless you are a pro, use Photoshop extensively or print large images, most people would get away with using a 3mp or less camera. Especially if you normally save / use the images on computer.
If you're dealing with purely computer-based photo viewing, or printing up to an absolute maximum of 8x10, then I'd say 3 MP is enough.
But bigger is definitely better. The biggest single advantage I find with having a higher resolution (i.e. more MPs) is that I can crop my photos and still retain satisfactory print quality when I print big.
Also, one needs to bear in mind the actual differences in resolution when comparing camera specs. An 8MP camera may contain double the total amount of pixels that a 4MP camera has, but you have to remember that this does not mean that the 8mp camera will produce pictures twice the size of the 4MP one. The percentage difference in linear vertical and horizontal dimensions is probably less than 50%, let alone 100%.
D
But bigger is definitely better. The biggest single advantage I find with having a higher resolution (i.e. more MPs) is that I can crop my photos and still retain satisfactory print quality when I print big.
Also, one needs to bear in mind the actual differences in resolution when comparing camera specs. An 8MP camera may contain double the total amount of pixels that a 4MP camera has, but you have to remember that this does not mean that the 8mp camera will produce pictures twice the size of the 4MP one. The percentage difference in linear vertical and horizontal dimensions is probably less than 50%, let alone 100%.
D
It's good to see someone viewing the megapixel question with fresh eyes.
Just as I had two film cameras, a 'serious' one and a 'toy', I now have exactly the same set-up with digital: a 6.1Mp DSLR and a 3.2Mp compact.
Here is a tale: a little piece snapped off the door of the compact, and as it was under a year old I returned it for a refund (as it was no longer a current model). I was delighted to find that I could then get the model two levels up for less money, so got the 4Mp version. Yippee!
However, enthusiasm clouded my better judgement. The 4Mp version was noticeably less sensitive to light, meaning that either the flash kept going off when I didn't want it to, or I had to run the camera-shake risk. It had functions I simply didn't want, like video with sound...? (WTF?! If I want a video camera, I'll buy one). Plus, standard file size was 2.5Mb which was simply too big for the purpose. If I want to do serious stuff, I have the DSLR. So I bought a refurbished 3.2Mp from eBay and will sell the 4Mp one.
And the compact did most of the images at www.blokewithacamera.co.uk. Technical hurdles aside, it's not what you've got, it's how you use it.
Further reading:
www.kenrockwell.com/tech/mpmyth.htm
Just as I had two film cameras, a 'serious' one and a 'toy', I now have exactly the same set-up with digital: a 6.1Mp DSLR and a 3.2Mp compact.
Here is a tale: a little piece snapped off the door of the compact, and as it was under a year old I returned it for a refund (as it was no longer a current model). I was delighted to find that I could then get the model two levels up for less money, so got the 4Mp version. Yippee!
However, enthusiasm clouded my better judgement. The 4Mp version was noticeably less sensitive to light, meaning that either the flash kept going off when I didn't want it to, or I had to run the camera-shake risk. It had functions I simply didn't want, like video with sound...? (WTF?! If I want a video camera, I'll buy one). Plus, standard file size was 2.5Mb which was simply too big for the purpose. If I want to do serious stuff, I have the DSLR. So I bought a refurbished 3.2Mp from eBay and will sell the 4Mp one.
And the compact did most of the images at www.blokewithacamera.co.uk. Technical hurdles aside, it's not what you've got, it's how you use it.
Further reading:
www.kenrockwell.com/tech/mpmyth.htm
What megapixel rating would you need to get 300dpi pics or above.
This is what most printers require for mag pics etc isn't it?
So how do you know a pic will be worth money?
I am happy if the pic comes out how I want it. Yet seeing some of the pics posted on this forum, I could imagine many of them in magazines / calanders etc.
This is what most printers require for mag pics etc isn't it?
V6GTO said:
Mark,
I've got a Canon D20 (8.2 MP) and shoot on the finest setting all the time on the basis that maybe, just maybe, I might shoot a photo that will worth money to the press/whoever, and would hate to think I couldn't sell it because the quality wasn't there.
Martin.
So how do you know a pic will be worth money?
I am happy if the pic comes out how I want it. Yet seeing some of the pics posted on this forum, I could imagine many of them in magazines / calanders etc.
I'm not a photographer in any way except the "point and shoot" snaps variety.
As the largest print I make are usually 6x4", I've found that there's no difference at all when switching my Ixus down to ~3MP from its maximum of 4MP.
Therefore, most of the time I leave it switched down a bit and can get more snaps on the memory card...
As the largest print I make are usually 6x4", I've found that there's no difference at all when switching my Ixus down to ~3MP from its maximum of 4MP.
Therefore, most of the time I leave it switched down a bit and can get more snaps on the memory card...
It really depends on what you want to do with the image.
The optimum print resolution for inkjet output is 300 or 360 dpi, however you'll still get good results down to 150dpi, so you can work out how many pixels you'd need for a certain print size.
At 150dpi, an A4/A3 print will require about 1.8MP/3.6MP
At 360dpi, an A4/A3 print will require about 10MP/20MP
Of course, if you just want to put photos on a website, or print out at normal photo sizes, then you won't really need more than around 3 MP.
Also, the quality of each pixel can be an issue. By cramming more pixels onto a sensor, the amount of noise (random colours) each pixel generates compared to the image information can increase, thus it has been known for an upgraded camera to give poorer image quality than the model it replaced. Sometimes progress in sensor design makes up for this (Canon 20D gives similar quality to 10D, despite smaller pixels), but it's always best to check out reviews on sites like dpreview.com to see how different models stack up.
For this reason, you'll find that an 8MP DSLR will give better image quality than an 8MP compact, partly because the sensors are larger, and thus the pixels are larger too. In fact, you'll almost certainly find that even a 4MP DSLR will give superior image quality to an 8MP compact.
Additionally, even if you don't have sufficient pixels to begin with, you can use Photoshop or an app called "Genuine Fractals" to enlarge the image.
Hope this helps!
The optimum print resolution for inkjet output is 300 or 360 dpi, however you'll still get good results down to 150dpi, so you can work out how many pixels you'd need for a certain print size.
At 150dpi, an A4/A3 print will require about 1.8MP/3.6MP
At 360dpi, an A4/A3 print will require about 10MP/20MP
Of course, if you just want to put photos on a website, or print out at normal photo sizes, then you won't really need more than around 3 MP.
Also, the quality of each pixel can be an issue. By cramming more pixels onto a sensor, the amount of noise (random colours) each pixel generates compared to the image information can increase, thus it has been known for an upgraded camera to give poorer image quality than the model it replaced. Sometimes progress in sensor design makes up for this (Canon 20D gives similar quality to 10D, despite smaller pixels), but it's always best to check out reviews on sites like dpreview.com to see how different models stack up.
For this reason, you'll find that an 8MP DSLR will give better image quality than an 8MP compact, partly because the sensors are larger, and thus the pixels are larger too. In fact, you'll almost certainly find that even a 4MP DSLR will give superior image quality to an 8MP compact.
Additionally, even if you don't have sufficient pixels to begin with, you can use Photoshop or an app called "Genuine Fractals" to enlarge the image.
Hope this helps!
ehasler said:
It really depends on what you want to do with the image.
The optimum print resolution for inkjet output is 300 or 360 dpi, however you'll still get good results down to 150dpi, so you can work out how many pixels you'd need for a certain print size. . .
. . . Additionally, even if you don't have sufficient pixels to begin with, you can use Photoshop or an app called "Genuine Fractals" to enlarge the image.
Hope this helps!
Sorry, I meant Print Companies. I have occasion to send pics for articles etc in work.
I have used Photoshop to change the dpi. Doesn't this affect the pic quality though?
pdV6 said:
I'm not a photographer in any way except the "point and shoot" snaps variety.
As the largest print I make are usually 6x4", I've found that there's no difference at all when switching my Ixus down to ~3MP from its maximum of 4MP.
I must admit to using my Canon to its max 3.2mp (fine setting), but for storage etc when you are happy with the pic (crop, Photoshop etc), if I had a larger mp camera, I think I would still store them at around 3mp size.
Ex-Biker said:
Sorry, I meant Print Companies. I have occasion to send pics for articles etc in work.
Depends. Some places just request a file size of more than 'x' - though that's no arbiter of picture quality! You could always ask them and find out what there specs are...?
Ex-Biker said:
I have used Photoshop to change the dpi. Doesn't this affect the pic quality though?
It just resizes the whole image. Going from (say) 72dpi to 300dpi just makes the image and file size bigger. You can make any image 300dpi if you want; it has nothing to do with the actual quality!
simpo two said:
It just resizes the whole image. Going from (say) 72dpi to 300dpi just makes the image and file size bigger. You can make any image 300dpi if you want; it has nothing to do with the actual quality!
IIRC there are a few ways of resizing for dpi in PS. One does actually alter the physical dimension of the image. The other doesn't (for this option you check "Resample Image" and PS makes educated guesses at what the extra pixels should be).
The former is the only one to use and has been noted, if you want to print it out do not drop it to less than 150dpi.
Genuine Fractals etc are a different kettle of fish altogether. Apparently work very well but not on all images. Use a variety of tricky sums to interpolate (educated guess) new pixels values.
Funny thing MP's. You would think more is better but a lot of people forget about a thing called noise. (Ant type specs that sometimes make digital pictures look fuzzy). The more MP you cram on the CCD, the more niose you get unless of course you make the CCD bigger.
So in reality, I've read reports where a lot of 3.2-4MP compacts have much better quality pictures than 7MP compacts because the CCD is the same size.
This does however apply to DSLR's as the CCD size is significantly bigger than compact digital CCD's so therefore little or no noise.
I just bought a Canon EOS 300D with 6.4MP and the quality is bl**dy amazing and much better than my mates 7MP sony compact camera even in automatic mode.
Keep this in mind when buying a compact!
So in reality, I've read reports where a lot of 3.2-4MP compacts have much better quality pictures than 7MP compacts because the CCD is the same size.
This does however apply to DSLR's as the CCD size is significantly bigger than compact digital CCD's so therefore little or no noise.
I just bought a Canon EOS 300D with 6.4MP and the quality is bl**dy amazing and much better than my mates 7MP sony compact camera even in automatic mode.
Keep this in mind when buying a compact!
Ex-Biker said:
Sorry, I meant Print Companies. I have occasion to send pics for articles etc in work.
I have used Photoshop to change the dpi. Doesn't this affect the pic quality though?
I think that the normal requirement for commercial printing is 300dpi, but probably best to check first for their requirements.
Changing the dpi can do two things:
1) changes no of pixels in image for a set size.
E.g., if your output size is set to 10x10 inches, and dpi set to 150, then your image will be bumped up to 1500 x 1500 pixels, with Photoshop (or other resizing app) guessing what the new pixels should be.
Quality will be less than an image that had 1500 x 1500 pixels to start with, however whether it's noticable to the human eye will depend on the original image, amount it is resized and the settings used.
2) changes size of output for a set no. of pixels.
E.g., if your image is 1000 pixels x 1000 pixels, your print will be 6.6" x 6.6" at 150dpi, or 3.3" x 3.3" at 300dpi.
The image is still 1000 x 1000 pixels, and the dpi setting is only relevant when the image is output.
Ex-Biker said:
I have used Photoshop to change the dpi. Doesn't this affect the pic quality though?
I'm lazy, so I've copied this post I made a few months ago,
"Resolution is a very misunderstood subject indeed. To quote a pixel size (e.g. 600x400) in relation to a resolution (e.g. 72DPI) has absolutely no meaning when the image is being displayed on a computer screen. A 600x400 picture is EXACTLY the same whether it is 1 DPI or 1000 DPI - it is always 600x400 pixels.
This is not the same if you are quoting the picture size in physical dimensions, i.e. inches/centimetres/whatever. For example, a 6"x4" print at 10 DPI is made from a 60x40 pixels photo, whereas the same print at 300 DPI is made from an 1800x1200 pixel image. Obviously the higher DPI image is a better quality in this instance.
The difference is due to the fact that a pixel is not a set size, whereas an inch obviously is.
"
hope that helps
Also,
ehasler said:
A lot of sense - listen to this man...
My cameras 8mp. I shoot from 1600x1200 upwards depending on what it is.
Pics for ebay sales or genberal web crap = low res.
Anything else = top res unless I'm short of card space , I can always downscale them later if needed.
Higher MP on same sized sensor does give more noise, but this is usualy at poorer ISO's (my camera at ISO64 is mostly noise free) and you can always remove the noise with noiseninja or whatever.
8mp gives me more detail and a better ability to crop than lower resolutions. But for printing full frame on A4 3-4mp is fine - if thats all you'll do then you dont need higher.
Pics for ebay sales or genberal web crap = low res.
Anything else = top res unless I'm short of card space , I can always downscale them later if needed.
Higher MP on same sized sensor does give more noise, but this is usualy at poorer ISO's (my camera at ISO64 is mostly noise free) and you can always remove the noise with noiseninja or whatever.
8mp gives me more detail and a better ability to crop than lower resolutions. But for printing full frame on A4 3-4mp is fine - if thats all you'll do then you dont need higher.
All magazines require images at 300dpi. They need to be supplied as CMYK files as magazines print using the four colour process, ie using cyan, magenta, yellow and black films.
Most magazines would have their graphic designers or repro department check your digital files though, which would of course would be RGB originally. It would be quite easy for them to convert them to CMYK.
It is always wise, however, to supply information, such as '1 x RGB TIFF' when labeling your work. (RGB images would print as black and white if used in a four colour process.)
As far as resizing is concerned, your camera will capture the image at 72 pixels per inch. To resize the image to 300 pixels per inch, first uncheck the 'resample image' box. Next, set the pixels per inch to 300. You should now observe that the pixel dimension has remained unchanged whilst the physical dimension has shrunk. This method will ensure that you maintain the original amount of pixels and maintain optimum image quality.
It is always best to work with the largest amount of pixels available to you as this will give you greatest scope for cropping and/or enlarging at a later date, when manipulating and printing the image.
The amount of megapixels required depends on the physical dimension of the final image and the method of printing used. Large prints, ie A1 are often printed at 150 dpi because they are viewed from a far greater distance and the eye/brain resolves the image as being sharp. Closer inspection, of course, will prove otherwise. Lambda prints at A1 can be anywhere between 35-75MB. I've seen good A3 Lambda prints produced from a 7MB file (less than A4).
>> Edited by EmmaP on Tuesday 30th November 00:20
Most magazines would have their graphic designers or repro department check your digital files though, which would of course would be RGB originally. It would be quite easy for them to convert them to CMYK.
It is always wise, however, to supply information, such as '1 x RGB TIFF' when labeling your work. (RGB images would print as black and white if used in a four colour process.)
As far as resizing is concerned, your camera will capture the image at 72 pixels per inch. To resize the image to 300 pixels per inch, first uncheck the 'resample image' box. Next, set the pixels per inch to 300. You should now observe that the pixel dimension has remained unchanged whilst the physical dimension has shrunk. This method will ensure that you maintain the original amount of pixels and maintain optimum image quality.
It is always best to work with the largest amount of pixels available to you as this will give you greatest scope for cropping and/or enlarging at a later date, when manipulating and printing the image.
The amount of megapixels required depends on the physical dimension of the final image and the method of printing used. Large prints, ie A1 are often printed at 150 dpi because they are viewed from a far greater distance and the eye/brain resolves the image as being sharp. Closer inspection, of course, will prove otherwise. Lambda prints at A1 can be anywhere between 35-75MB. I've seen good A3 Lambda prints produced from a 7MB file (less than A4).
>> Edited by EmmaP on Tuesday 30th November 00:20
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