I bought a Nikon 5700 a few years ago. It was 5 megapix which I wanted so I can enlarge some pics. The only problem is I haven't figured out the darn camera yet. Too hi-tech for me. Get something easy and cheap that is point and shoot.

 

Ummm no......



I could be (and almost was) a smart **** and ask what you thought the difference betwwen DPI and PPI was.....

But since this is not a camera forum nor a digtial imagary forum nor a graphic designer forum, then only a few of us would laugh at it, so I wont....

There is no confusion they are the same thing.....

Crash course.... "Digital Images 101" (Simplified version)

Definitions

DPI = Dot per inch
PPI = Pixels Per Inch
Megapixel = 1 million pixels.
Pixel & Dot = Picture Element.

Depending on the media you are working in, the picture element is called Pixel (or pix for short), pel, sample, byte, bit, dot, spot, etc But its all the same thing.... A Picture Element.

The image taken by a digital cameras is made up of these Picture Elements known as pixels or dots. But they are not round, they are actually square so there is no space between them. There are advantages and disadvatages to squares, but thats more advanced and subject to debate and greatly depends on subject of the image.

MP Rating,
You get your images MP rating by counting the squares (aka pixels or dots) contained in the image. If you could set a camera at 8 million PPI/DPI then a 1"x1" picture would be an 8 megapixel image.

Another determining factor in image quality is the way a file is saved. Some have already mentioned .tiff's.
A TIFF image is 100% uncompressed it is known as a raw image. No data loss what so ever.
How ever, most 1 hour photo labs can not read .tiff format. So .jpeg is more commonly used. Jpeg is a compressed image, some data loss occors, the extent of loss is determined by the amount of compression.

The same camera company will use a lower compression for higher quality pics on thier higher end cameras. The cheaper camera's that company makes will use higher compression to save disk space but loss image quality.

Now you have an understanding of digital images.

Now for printed media.

A dot on a printer is actually a round ink "spot", so a digital image is converted to round pixels during a print job.

You can not take 72 PPI/DPI digital image, and print it at 300 DPI.
Well technically you can but it's silly. Where is the extra 228 dots in every inch coming from? They don't just magically appear some how.
You don't want to go over 300 PPI/DPI because the human eye is not capable of detecting anything finer than 300 DPI/PPI.
How ever if you take a 72 DPI/PPI image and shrink it by 25% (careful not to loss any Pixels) then you can increase it to 300 DPI with out losing a single pixel of the images data. Now you get image size or square area of an image + DPI/PPI.

That concludes the digital image lesson at this time, are there any questions?


To address your challenge,

For your challenge, not only do you have to take a picture of the same image with 2 different camera's under the same lighting, you also would have to use the same model of camera with different MP ratings.

However, what you are actually comparing by doing this is the resolution of the cameras photo (AKA DPI/PPI), not how many pixels there are in the image (aka the MP rating) nor how big the image is and not taking into considerating the file compression ratio. So your test suports what I said in my first post.

 

Mike,

OOOPS: Hey, I was doing this at work and missed your post.....plus trying to type with paws takes a while And that is Mr. Bow Wow to you

Woof
Bowser

 

just bustin' chops.... dpreview does have some fanatical people though!!

It's funny though..... whenever I consider buying something of substantial $$ nowadays, I start researching the forums for the thing I want to buy.... ie, looking at speakers for the wife's IPOD and came across www.iLounge.com .. some good info.... seems there's a forum for almost anything nowadays!!!

woof... my a$$$.....

 

Remember Dog's bite.....

WOOF
Bowser

Now back to the camera thread

 

Was looking at some cameras by DXG but reviews are mixed. Man I just can't generate much enthusiasm for camera research.

Hopefully I can get it sussed by the weekend.

I do appreciate everyone's comments though