Digital Camera Resolutions & dpi

[lenny22]

I am looking for some advice on the subject of digital camera resolutions. I am fairly new to photography and presumed that the number of megapixels were the key to resolution.

I have recently bought a 5 megapixel Sony DSCV-1 but have noticed that the maximum dpi resolution I can get is 72dpi. Samples from other sites always show this resolution for this camera.

I have also noticed that image samples for cameras such as the Nikon D70 can show resolutions of 300 dpi, or Canon EOS 300D at 180dpi for some samples.

The question I'd like to ask is whether these more advanced SLR cameras automatically take a higher dpi resolution image or whether the resolution can be manually adjusted on these cameras?

[castledude]

DPI is a meaningless term with cameras .. Ignore it it's just a number put in as a place holder.

The numbers that are important are the resolution (6MP, 8MP ect).

a 3000x2000 picture from a Nikon has the same resolution as the 3000x2000 picture from a Canon.

DPI does not really have any meaning except on flat bed scanners. When you scan at a certain resolution 300 dpi means you are getting 300 dots of information for each 1" of scanned image.

Printers will specify in DPI ... It is also pretty much meaningless. The important number for printers is PPI (which is very hard to find, and with multi colored inks is hard to calculate). The exception is Dye Sub printers which have and interchangeable DPI and PPI value.

[eddiep]

Here's another way to look at it: at 72 dpi, that 3000x2000 pixel image would make a print about 41 inches x 27 inches because of the relatively low "printing" resolution. However at 300 dpi (a very simple change in photoshop) that same image is only about 10 inches x 6 inches because of the higher, and necessary, resolution for printing. Both images, 72 or 300 dpi are the same size internally, about 17 megs.

FYI, most of my inkjet prints are made at 360 dpi, but that changes due to image subject matter and desired final size of the print. I shoot with a Canon 1Ds, so I have a lot of resolution to begin with, but the lowest I've ever gone was 85 dpi, that was to make a 4 x 5 foot print for a trade show.

Hope this helps, it's sometime confusing but it's not rocket science.