So it would really be the case that Microsoft have caused the confusion between DPI and PPI by their choice of an existing term to replace another existing term.
They have done this in other places, notably by assigning a file extension to a program when that extension was already in use by another program. This can result in the best error message that I have ever seen - click on one of the original files to use that extension and get:
ERROR, the operation completed satisfactorily.
when, of course, it had failed to do so.
I used this example for years when teaching on a software engineering course.

Geoff

Well actually, Algi, you were the one who introduced the Wikipedia link.
Moreover:
The Scantips author does not appear to know the difference between PPI and DPI. He does seem to concentrate on the monitor and printer - and ignore the graphics processor capability.

I know that the Windows resolution settings (in PPI, please note) are much cruder than those used by Apple, but either system offers a range of PPI settings regardless of the monitor. Even the fixed monitor built in to my G5 IMac has a choice of resolutions available in PPI.

Let me just quote a little bit from the rules of my Club:
Digital Projections submitted should be 8bit JPEG and at a resolution of 72 pixels/inch (so that entries may be e-mailed).RGB Mode and sRGB Colour Space.
1400 x 1050 pixels Landscape. Max height of portrait to be 1050 pixels.

You may note that the resolution is specified in PPI. An image to these rules projects quite well so as to fill a large projection screen. If printed (do note the IF), the size of a typical image would be 19.5 x 14.5 INCHES. A DPI value does not yet come into it, until I choose the (printed) image quality.

Sorry, Algi, but the link you provided earlier to a Wikipedia article included:
"The DPI measurement of a printer often needs to be considerably higher than the pixels per inch (PPI) measurement of a video display in order to produce similar-quality output."

If you take a fairly hi-res monitor, with a dot-pitch of 0.25mm, then that monitor has a native dot-pitch of close to 102/inch. What happens to the individual pixels which that screen can display is a matter for the setting on the graphics card. On our hypothetical 0.25 mm monitor, if the graphics card will not go beyond 800x600 pixels then that is it. What the printer prints out is a matter for the printer driver - which is quite happy to convert RGB into CMYK. Of course printers work in CMYK - if I open up my Canon i560 (so a few years old now) I will find 4 (count them, 4) ink cartridges inside Cyan Yellow Magenta and black.

If I take a memory stick to a printer and say "Print me this image" he will print it at the size (in inches, or mm, or cm)I have made the image. If I mail it to a printer he will ask for a size at a resolution (often pixels x pixels).

Geoff

For general info:
72dpi was the old Apple colour resolution. As such, it was used by a whole generation of commercial artists (and some other odd folk like vision Psychologists). This resolution will look OK on a screen or when projected (as the screen or projector will usually be better in resolution terms).

The follow on from this is that most graphics programs tend to use 72 dpi as a starting point (even if this gives the image a notional size of something like 30" x 40". This seems to happen even if the program has been written for a PC only.

Geoff

Don't get too confused, Blaze.
Open your picture.
Go to [Resize]
Now set your picture so that the longest dimension is 10"
Your resolution should now change to something like 300 dpi.
It will now print OK on to an A4 page.

If you want to crop - crop first, then resize. I resize my crops to 10x16 for competition (just fits well into A3), or 10X8 to give to family and friends (A4). This will give you some odd resolution values, probably.

Geoff

OK, so I started to read the rules.

A shot with a wide angle lens.
- Right, I have a good one of those (I think it is good, anyway)

Must be taken with a pentax camera ...
- But of course!

EXIF data must be included.
- How do I get EXIF data from a P50, when it does not generate any?

But seriously, the bit about EXIF data makes the bit about "Pentax camera" a bit of a joke as well. I went out that day with my P50 and a 24mm Tamron fitted, and a K200 with the 18-55 kit lens fitted. One shot with the P50 is one that I would like to find, scan, and enter. A shot taken a little while later got me a 2nd place in a Club competition - I cannot use it for this as the lens was set on 40mm at the time the shutter release went down. So, as written, the simple rules have an implicit "digital bodies must be used".

I really do not think that 35mm on a Pentax DSLR qualifies as wide angle, anyway, when it equates to almost a film era "standard" 50mm, when on a body that will generate EXIF data.

The idea for this comp is excellent - the detail is (IMHO) not.

Geoff

Does your wife know that you have this thing about legs?

Geoff (who can get by with just three tripods and two monopods)

The original "Magic Bullet" was Doctor Solomon's (later S&S Software dating from 1988 (Yes, thats right, the MSDOS era).
Ten years later, Network Associates (subsequently McAfee) bought the lot from Doc Solly.
Things were a lot easier in the DOS era, right up to Win 98.

It can be worth looking up (and downloading) The Ultimate Boot Disk.

Geoff

I guess that the link from JohnX is safe.
I tried to mail the URL to my gmail account, and my ISP rejected the URL as possibly containing a virus. So I typed it in by hand into Safari on my Apple Mac, and it opened without a problem. Same how-to-remove stuff as I found on another site.
The problem is probably that the URL contains a naughty word beginning with V.
Geoff

Either way, get a tripod first.
Mirror lenses can be good (not super, just good)and can often be found real cheap - and usually cheaper than a good 2X converter.
Some mirror lenses are very sensitive to a filter, and give mediocre results when one is fitted.
I would be inclined to see if you could borrow one to try out, and see if you like it - and how it performs.
Remember that a mirror lens will likely be f8 fixed, while a converter will drop the effective aperture of your zoom to more than this (i.e. smaller).
Geoff