All my images are at 72dpi (or ppi whatever!) straight from camera (K7).

I just uploaded a picture to a competition, and as the rules stated '300dpi' - so I had to change it. I bet hardly anyone else has bothered though! Maybe I'll win by default

DA 60-250 - 168mm, K5 - 97mm, so that's 265mm - but without lens hood presumably.

I wish you would get off your little hobby horse for once! It doesn't make any difference whether the OP has Photoshop or not.

The point was to try and illustrate that 72ppi is irrelevant to the resolution of the image for printing. However if she does have Photoshop (or similar) perhaps the additional info would be of use.

It's definitely a frog, but he's a very warty one!

Stamp your feet and demand a replacement camera (cheap way of getting a K5 upgrade!)

I interpreted the 300mm at a total physical length of the equipment.

I personally wouldn't bother trying to get telephoto shots of any of the big stadium events - unless you have somehow managed to get front row seats I think you're going to be too far and too high up, and you're better off going for 'ambient' shots. Just enjoy it and take your memento pictures, or maybe look for the sort of candid shots that the official 'togs may have missed.

Also be aware, there are special rules at Wembley Stadium - officially no DSLRs or cameras with interchangeable lenses, although I get the impression they apply the rule with a bit of discretion.

Bill, you said that so much more succinctly!

(The 'Print Size' of the image is occasionally relevant, for example if you are specifically told by someone else - e.g. a magazine editor - to provide them with an image at A3 at 300dpi. In this case you would place a tick in the 'Resample Image' check box when you resize the image, and add the dpi and print size dimensions that you want. The image will then be resampled - adding or subtracting extra pixels to make it exactly the size and dpi specified).

It doesn't matter whether they're at 72dpi or 300dpi.

In Photoshop, you can change the dpi of the image by going to 'Image Resize', unchecking the 'Resample Image' tick box, and changing the dpi to 300. The number of pixels will not change. When you view the image at 100% on the screen, it will be exactly the same. You will however notice that the so-called 'Print Size' of the image becomes less - proportionately to the new dpi setting. You have changed nothing of any consequence when you print the image, though, because when you print, the image will be printed at whatever print size your paper is, NOT at the computer's meaningless 'Print Size' tagged to the image.

72 dpi just happens to be a common monitor resolution, but again, the dpi of the image doesn't have any effect on the image's resolution - the number of pixels in the image does - a 4000 x 2500 pixel image is a 4000 x 2500 pixel image whether the computer says it's 72dpi, 300dpi, or 1200dpi.

PS you can also use an M lens in Av mode, but it will always be 'wide open' at f1.4 whatever aperture you select on the lens. In many situations, this will be appropriate, if you've bought the lens specifically to make use of the large max. aperture!