Rain - no problem. At least one user even tried their K10D/K20D under the shower!!

Do you have to have weather sealed lens - yes
(ie SMC-DA* 16-50 f/2.8, SMC-DA* 50-135 f/2.
Making a weather sealed lens is a costly process

For me (without sealed lenses) it gives me the confidence that I don't have to be paranoid about getting the camera wet (or dusty for that matter).

The IQ of the K20D is fabulous! IMO leaves the D100 & D200 standing, the gap may be closer with the D300. The D300 is capable of some very nice results... but then the K20D is superb and I've been extremely happy with its quality!

Best thing - try out the cameras, check out some real-world samples on the 'net (e.g. at www.pbase.com they have a search facility which is helpful - but bear in mind that many users are novices and snap-shooters!). You'll get quality images from any brand these days - but how much it will cost you can vary greatly. For example, the Pentax lenses have fabulous colour, bokeh (rendering of out of focus areas), and contrast. They are really difficult to beat, and their price is very competitive. Other cameras may have faster frames-per-second, other features (like complex remote controlled flash systems of the Nikon), and perhaps lens choices.

If you can give us an idea of what you want to photograph, what your experience is, then I'm sure you'll get a more direct answer

Matt

Hmmm. Long answer coming up

Unlike TIFF, a JPG is split into two component parts. There is the colour information and the luminance information. Even at 100% the JPG format still contains far less blue information when compared with the other channels (11% IIRC).

Now whether that matters depends on what you're going to do afterwards... if you're going to push around the colour channels and try and lift shadow detail from the darkest depths of the image then use TIFF - there'll be more info there. If you need to basic dodge & burn, colour cast adjustments - ie 95% of the usual photographic stuff then JPG should be fine.

However, as I hinted, if you work with layers within Photoshop (which are TIFF-like internally) then you can always slide in a TIFF version if the JPG shows signs of falling apart (because you've pushed it too hard).

For disk-space, speed, and convenience a JPG works just fine

Matt

#1 for me
IMHO, the B&W shots could do with a little more contrast - preferably a "Selective Color" layer in PS and adjust the black content for the "Whites" and "Blacks"

Matt

Ditto

Though I can see some of the potential benefits of MF... but I reckon that FF dSLR should be cheaper and should appeal to more users. But whether Pentax would make a better ROI on FF-dSLR vs MF is anyone's guess!

Are Pentax still making MF lenses??
If not, then that pretty much wraps it up
Shouldn't be too hard to resurrect lenses like the SMC-FA 24-90 etc for FF (I still have a little cache of FF lenses )

Matt

You may also find Depressing Review's review of the D90 useful - especially the comparisons between the D90 and K20D
http://www.dpreview.com/reviews/nikond90/page20.asp
To me, the K20D has significantly more detail, although more noise (which is Pentax's design mantra - do little to the image and allow you to post-process it since it's harder to "undo" heavy processing that was applied in camera)

But as has been said, the best thing is to handle both cameras
Matt

ibcsweb,
You have a few options:
1) Use standalone RAW converter (like Silkypix or Capture One) and use the JPG or TIFF files in Elements.
2) Use PEF in camera and use the Adobe stand alone RAW converter to produce DNG files.
3) Shoot DNG in camera (which is larger)

Option 1 is the best approach if you want to maximise image quality
Silkypix has a free version - I'd suggest starting with that and working out which way you want to go. Since using Silkypix the need for Photoshop work on most shots has been reduced drastically - ideal for events and weddings etc - you get print-ready shots pretty much straight out of Silkypix Developer Studio (paid version).

Can't remember which version of Elements handles DNG... but definitely Elements is a good choice. It's fast, it's cheap, and means that if you migrate up to full Photoshop at some later time then you still have a wealth of knowledge and experience that's valid.

Elements is a fine package, and can be pushed "harder" with books and websites like www.hiddenelements.com

Hope that helps!
Matt

Comparing the K20D with Nikon should really be against the D300

Yes, the D90 is full of fun and gadgets and as far as I've seen on the 'net delivers the goods.

However, much of it will come down to how the camera feels, how logical the functions are to you, and your wallet. Live View is a feature... I've used it once on the K20D - the viewfinder is the place to "see" the shot

You'll certainly get more lens for your money in Pentax though - with a similar spec'd system in the D300 being about 50% more expensive compared to the K20D.

Hope that helps!
Matt

I use this rule of thumb:
If I can get 99% where I want inside Silkypix then I'll save as JPG (you can adjust the quality), then do minor edits in Photoshop and save as PSD file (because I always use layers).

If I need to wrestle with the shot a bit (like severe dodge & burn etc), or anticipate printing in large format, then I'll save as 8-bit TIFF. If there's a ton of PP to do then I'll use 16-bit TIFF - but John is correct - you'll not be able to access many of the filters and facilities. Photoshop CS2 gives you most of what you need when working with 16-bit.

It does depend on (a) how many shots you're dealing with, (b) what you need to do to the image in Photoshop, (c) how much hard drive space you have

Don't forget that you can always go back to the RAW converter and re-export the image If you work in layers in Photoshop and save the full PSD file then you can always go back and pull in a TIFF file later (If you've found you have a winner!)

Matt

You can say it... but I might not be listening
Matt

Having trouble finding time... one of the big troubles is which direction to take this flash guide. I've included a chapter on various common lighting problems and some hints on how to tackle them, plus a chapter on the settings for various dSLRs I have (or had). But there's always some cross-over of information, and getting this penned sensibly is proving challenging!
It all just "fits" together in my head... but putting it down is harder
Matt