6mp vs. 8mp. Is it a big difference?

[Bristol Pete]

As above, is the difference between 6mp and 8mp that much, when shooting, printing etc...?

Thanks,

Pete.

 

[T0MAT01]

Put it this way, the more pixels you've got means you can crop/rotate an image without losing too much detail.

6 MP will no doubt give great quality prints but then it also depends on how large you will be printing as to the final dpi.

 

[Bristol Pete]

Personally, I cant see myself going over 7 x5 but you never know....

Is 300 x 300 dpi the max anyway?

Thanks.

 

[richard plumb]

the correct answer - no, not really. Even when cropping, its a tiny border relative to the entire image. Some of my favourite pictures are from my 2.5mp sony 505v


My gut answer - yes it is. Although the Nikon D50 and Canon 350d are both equally as good, I just couldn't get past the 6mp, so for similar money I bought the canon. Not the only reason, but one of them.

 

[barongreenback]

Depends what you're looking to do. If you are looking to blow up photos for A3, like cropping your photos then yes, it does make a difference. However, most of the reviews comparing the Canon 350d against the D50/70/70s don't see any difference between the two. I'd do some thorough investigation into what cameras you are comparing in terms of image quality before worrying too much about megapixel count.

 

[Bristol Pete]

I'd do some thorough investigation into what cameras you are comparing in terms of image quality before worrying too much about megapixel count.

Am doing that exactly, hence the 6 v 8 question.

Thanks.

 

[T0MAT01]

Personally, I cant see myself going over 7 x5 but you never know....

Is 300 x 300 dpi the max anyway?

Thanks.

I know what you mean, but once you've got a taste for photobox's 10" x 15" it's hard to resist.

As for the max dpi, the Canon i9950 says it will print 4800 x 2400 dpi!

 

[mr jones]

depends if your going to require large output files for large prints or not.


personally if given the choice between to cameras at a particular price point id pick a 6mp camera with a better lens or processor than a 8mp pixel camera thats had the glass skimped on.

 

[mr jones]

I know what you mean, but once you've got a taste for photobox's 10" x 15" it's hard to resist.

As for the max dpi, the Canon i9950 says it will print 4800 x 2400 dpi!

print resolution is a completely different onion to DPI.


300dpi in an image is pretty much a standard for the likes off magazines and publications, most cameras will output at 72dpi (web resolution) unless you tell the raw software to do otherwise.


resolution does go higher than 300dpi but for most applications this isnt required

 

[senu]

Put it this way. If I could have an 8 megapixel camera that is not better ( but not in anyway worse) than a 6 I would have the 8!

However because PQ detail and sharpness are not strictly a function of the megapixel rating I would be wary of buying a camera just on that basis. The PQ difference in the 300, 350D 20D D50 D70/s is not explained by the 6/8 difference. rather the lenses, digital image processing ( and the photographer .. no not really) play a big role. However a geneorus crop in a 10 megapixel pic would retain enough information over an image originating from a 6 megapixel one with more modest or even no croppping.

There are some point and shoot 8 megapixel cameras which do not touch the 300D or D50/D70. for quality. They have very small sensors on which the 8 million pixels are fitted: doesnt really work.

Thus in the 8 million tiny light recieving units vs 6 million bigger light recieving units: the 6 win hands down.

 

[ush flynn]

print resolution is a completely different onion to DPI.


300dpi in an image is pretty much a standard for the likes off magazines and publications, most cameras will output at 72dpi (web resolution) unless you tell the raw software to do otherwise.


resolution does go higher than 300dpi but for most applications this isnt required

300dpi will get you pretty high quality prints although not the highest, magazines tend to use a res of 175dpi i believe, sometimes topping at 220. The glossier it is the higher the dpi might tend to be

your printer might say its 5750dpi which in a way is true, seeing as printers lay ink ontop of ink to create different colours, but it it isnt one point of ink for one dot on image. Try opening an A4 document at 5750dpi then fill with a 3 colour gradient....opps did it break your computer?

 

[MikeC]

is the difference between 6mp and 8mp that much,

the way the numbers are calculated means that it is not a staight-line function.

For an example a 2MP camera will create an image approx 1680 * 1260.
To double this resolution (note both vertical & horizonal resolutions) - effectively 3360 * 2520 - you would need an 8MP camera.
So the difference between 6MP & 8MP is not particularly significant.

JMHO

Mike

 

[MattB1]

I think there's confusion here between ppi and dpi.

Pictures on a PC screen are measured in ppi = pixels per inch. Printers print in dpi = dots per inch. They aren't the same thing.

 

[MikeC]

Oh and one other thing - if your 8MegaPixel camera generates an image 3360 * 2520 then, should you print a picture from this image using a 2800dpi printer, then the printer could print the image at a size of 1.2 x 0.9 inches with no loss of detail ..... thats a very small picture !

Should you wish to print a more sensible sized picture, then the software/print driver is going to fill-in and apply some image processing function to the picture.

Obviously, the more MegaPixels, the less 'enhancement' will be needed... so the higher the better....

HTH

Mike

p.s. this is all supposition, but I can't think it works any differently.. unless someone knows better

 

[richard plumb]

mike,

printer dpi doesn't really bear any relation to the original image. They may say 'five squillion dots per inch' but that has to cover them having to mix lots of only 3 or 6 coloured dots to make the original dots. So one dot of your original image will be many dots of printer ink.


around 200dpi is fine for most prints, as the larger the print, the further you are likely to view from.


72dpi is misleading IMO. Even if your camera marks that, most photo processing labs consider the actual dimensions of the original - you won't suddenly get a 6x4 print of a tiny portion of your original

 

[MikeC]

printer dpi doesn't really bear any relation to the original image. They may say 'five squillion dots per inch' but that has to cover them having to mix lots of only 3 or 6 coloured dots to make the original dots. So one dot of your original image will be many dots of printer ink.

agreed richard, that does make sense - I incorrectly assumed the printer has every colour & ofcourse it doesn't.

Thx

Mike

 

[RimBlock]

Rough rule of thumb......

Printer resolution / number of inks = dpi

No need to worry, that is all I am going to say about dpi

RB

 

[barongreenback]

Am doing that exactly, hence the 6 v 8 question.

Thanks.

Well...then enlighten us? You're asking a rather abstract point if you don't tell us which cameras you are looking at. The point I was making that the difference between a 6pm Nikon D70 is negligible compared to an 8mp Canon. So no, you are not comparing qualities, you are comparing megalpixels - an entirely different question. There is no hard and fast rule comparing a 2mp difference on most cameras. Sensor quality plays a much bigger role.