Screen quality is not only dependent on the resolution of the screen; much more that of of the basic "cast" of it (is it yellowish? bluish? purplish?) and whether the colors are vivid enough.
Unfortunately, most PDA screens on the market are pretty lousy. The two main reasons for this are as follows:
PDA's are excellent digital photo wallets. That is, they WOULD be excellent if they had screens with great contrast and vivid colors. Too bad not even the "latest and greatest" PDA's offer this functionality. Sure, you can show your pictures on even an iPAQ 38xx (maybe the worst TFT PPC of all time), but nobody will really enjoy them because of the sub-par contrast and very strong purple cast.
Therefore, in my test, I tried to find photos that have strong red/white/green components. Furthermore, I've added some of my color bars.
I've put to test all my color Pocket PC's (and my palmOne Zire 71, which has an extremely good, vivid screen). Before you ask: yeah, I own all of them and also the PsPC's in the background. Of course, I didn't want to enter old, B&W PsPC's in the test ;)
These are as follows:
Eagerly waiting the test pics? Well, here they are. I've used a Nikon Coolpix 5700 on a semi-professional Manfrotto tripod to take the pictures at 5 Mpixel and Fine JPEG. EXIF infos are present in the test JPEG's.
Note that I've used auto color balance. This is why, on some pictures, only the E-125 seems to have the right color balance. Don't let this mislead you: it's clearly the E-125's yellowish basic cast and warm colors that "fooled" the camera's color balance to switch to colder colors. In my next article, I'll use non-auto color balance to achieve comparable results.
The machines, from left to right: iPAQ 3660 (same screen as in all 36xx/37xx iPAQ's), iPAQ 2210, Fujitsu-Siemens Pocket Loox 720, Casio E-125 and palmOne Zire 71.
Let's see how the grass' green is rendered by the PDA's. The original picture was the following (this file was given straight to the PDA's - you can also do the same by saving the picture and loading it to the PPC. Where there was no built-in picture viewer (PL720's Album, 2210's WM2003 Pictures, Z|71's Photos), I used LimeLink's CEpicture - http://www.limelink.com/en/cepicture/). The original photo was taken on the river Matkusjoki, near Sonkajärvi, Finland, July 2004:
And the results (click on the image for the original, 5 Mpixel picture!):
As can be clearly seen, the Casio doesn't really excel at reproducing green colors; even the otherwise quite bad 2210 seems to be better in this respect.
This is maybe the best test picture of all because of its really warm colors. Original (a Finnish friend's children):
PL720's colors are by far the best. Casio's colors aren't bad either, but they're clearly much more "washed out" than those of the PL720. The two iPAQ's are clearly the worst.
Original (taken at the Summer Services of SRK, Finland, July 2004):
Pay special attention to the young lady's red coat!
Original (also taken at the Summer Services of SRK, Finland, July 2004; also pay attention to the red coat!):
Original: an ostrich egg from a Finnish ostrich farm. Especially strong warm colors and blue. The closest to the original is definitely the PL720; the E-125, though has a good rendering of the warm colors, is far too warm and is, therefore, not very natural (check out the yellowish cast on the hand and compare it to PL720's rendering of the same colors!):
Incidentally, the PL720's visibility range is pretty good. Two people can use it as a digital photo wallet at the same time with little (but certainly visible!) quality degradation, comparable to the 2210 or the Zire71. The E-125's quality degradation, when two or even more are staring at it from different angles, is much larger.
From the usual, straight position:
From the left (to see whether a particular screen has natural colors, or, at least, visible from the given angle):
From the right: