What should Photo file size be?

RussA

RussA

RussA

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30 Oct 2007
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Bought the wife a digital compact camera for xmas, a 7Megapixel kodak, and took half a dozen shots with it. The file size for each pic was about 1 Meg.

My old canon powershot s20 - a 3megapixel camera produces files of about 2.5-3Meg.

Shouldn't the new 7 megapixel camera be producing file sizes of about 5-7Mbytes (when set to 7Megapixel resolution of course!) or am I missing something here???

Thanks.
 
Maybe you havent set the resolution to the maximum?

Sometimes they preset on Small or Medium sized images, and not 'Fine' detail.
 
I went through every available menu, and there was only 1 relevant one, and that was set to 7Mp. Took it back to the shop, and the woman behind the counter said "oh they all produce file sizes of about 1 Mp" - I chose not to get into a debate with her. Should have added that the files were jpg's.
 
My D40x produces JPEG's between 400 to 1MEG+ and RAW's at around 8-9MEG

Was your camera set to TIFF? 2.5-3MEG for a JPEG seems a lot.

TrUz
 
On the old canon producing the 2.5Mp files from a "3.1Megapixel" sensor, the picture resolution was set to fine, and they were def jpg's - just checked.

This is why I don't understand the 7Mp of the new kodak compact only producing 1Meg files - or this is just deceiptful advertising where the cam may have a 7Mpix sensor but is only capable (for the reason that I can't determine) of producing 1Meg files???
 
1megapixel != 1megabyte, the filesize can be affected by a number of things - for example how much of the image is interpolated. A 7mp point and shoot may only be able to record a smaller number of pixels, and interpolates the rest.
If the image size matches 7mp (2000x3000px ish or something like that, just multiply the dimensions) then its 7mp, but this really has less to do with the quality of the image than the adverts make people believe...

Check that first, and you'll know for sure if it is 7mp, after that it's entirely your own opinion on whether the image quality is any good :)
 
How do I upload a pic? For the record, I'm comimg rapidly to the conclusion that the camera is probably not going to produce a 6-7Mp file, and its simply marketing b******t for the manufacturer to call it a "7megapixel" camera when it clearly can only product 1Meg files... should have known better.

So, next question - who makes the best £100 compact digital cam....:D
 
RussA I think you are confused about the difference between a megabyte and a megapixel.

Google F T W.
 
Bes said:
RussA I think you are confused about the difference between a megabyte and a megapixel.

Google F T W.
Click to expand...

What I read is that he can't understand why a 3 megapixel camera produces photos that are about the same file size as a 7 megapixel camera. If a 7 megapixel camera is capturing all that extra information, why isn't it resulting in a bigger file?

Part of the answer will be that the 7 megapixel camera will be compressing the image more.
 
Surely if he just looks at the EXIF data or opens it in GIMP or PhotoFiltre and looks at the canvas size, he will have his answer? My guess is that it is just compression or the camera is not in 'fine' mode or something.
 
Helium_Junkie said:
1megapixel != 1megabyte, the filesize can be affected by a number of things - for example how much of the image is interpolated. A 7mp point and shoot may only be able to record a smaller number of pixels, and interpolates the rest.
If the image size matches 7mp (2000x3000px ish or something like that, just multiply the dimensions) then its 7mp, but this really has less to do with the quality of the image than the adverts make people believe...

Check that first, and you'll know for sure if it is 7mp, after that it's entirely your own opinion on whether the image quality is any good :)
Click to expand...


1megapixel doesnt = 1megabyte, its easier for me to quote than explain

"First, an image's actual size--the amount of memory it will consume--is the number of pixels in the image multiplied by the bit depth. So, for example, a typical 3-megapixel photo with dimensions of 2,048x1,536 has 3,145,728 pixels; if it's a 24-bit photo, that means each pixel needs 24 bits of data to describe it, or 75,497,472 bits. Converting the units makes that 9MB. "

Thats uncompressed and most cameras save the image as compressed jpg, also there arnt many cameras out there these days that interpolate, Fuji used to use this techniche, maybe they still do but not may others have used it.
 
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