I'm using the normal CPL B+W Käsemann filter on my DA*16-50 without vignetting so only use the CPL and it should be alright.
It's btw never wise to stack filters it really degrades the image quality and might effect even the operations of the AF system.

The mount on the Pentax is directly mounted on the metal chassis inside on all there K DSLR camera's so they should be pretty strong.
Some other manufactures don't use a metal chassis on their budget camera's or even mid ranges one so their mount is mounted on plastic... One more reason to buy a Kx or Kr instead of another brand

The only filter i use are CPL and those are high quality B+W Käsemann MRC filters so anything but cheap.
I've 3 of those, 1 49mm that fits on the DFA100 and the DA40, and one for ech of the DA* lenses.
I also have a GND Z-Pro set, i forgot the brand at the moment

For protection i've almost always the hood on my lenses and a hood also boost the contrast since it prevents flares so delivering better image quality.

Here is a read about filters as protection and the conclusion is that with todays tough coatings that they only degrade your image quality since they don't give much extra protection.
http://www.luminous-landscape.com/columns/sm-feb-05.shtml

Here is a (funny) chart to see if you should work for free or not.
http://jhische.com/sneakpeek/workforfree.jpg

Basicly you should only work for free for family, very good friends and some charity if you support there cause and you keep the rights over your photo's and have the freedom to shoot/do what you want.

The man (haircutter) does use it for his profession/business so he's getting better of it while you spend your time and effort on the photos. It's only normal to ask a small fee to at least cover your time and effort, maybe he should give you 6 free haircuts or something like that

I believe i've notice that the DA*16-50 does push some air out but it can be me... I've used the DA*16-50 inside a swimingpool but only the front element fogt up and not the inside so it seems to work somehow, assuming the DA*60-250 has the same build quality you've something to comapre it to at least...

Never notice something with the DA*50-135 but everything is internal there so it doesn't change volume.

hmmm... Pentax did the modification on the spot at photokina 2006 for €49,- you can also send them to (local) pentax and they will replace the grip for the same price.
I've asked that to my local dealer and they contacted Pentax straight away to ask.

Don't know if they will still do that?
ps. the grip also fit on the K10D


I would say contact pentax, they did it for the K10D and K20D so big change they also do it for the K7 and the K5

This btw the second time we see a silver DA40mm limited, i wonder if anyone can thing of the first time

Do you mean that Adobe will actually change their files because Pentax want something?

If read the rules of use off DNG there is a lot that Pentax can add to the file as long as the key things are in it that are needed to create the photo.

DNG is actually more a container then a file, the image information itself is based on the TIFF/EP standard, you can make DNG fully TIFF/EP compatible but you also have the options to embed the PEF file also in the DNG file for example.

ps. aren't most RAW files not based on TIFF so what is the real difference in quality?

If you look at the RAW photos on your camera you're actually looking at the JPG thumbnail.

I don't think a program on the PC adds data to your RAW file because it creates the photo from the raw data and not from the JPG file and if you save the edits you most of the time end up with a sidecar with DNG the side car is embedded so it might become slightly larger (few KB).

ps. if you change the image settings like contrast, saturation sharpness while you shoot in RAW those are actually applied to the JPG thumbnail. Not sure if you can change the size...

My comment was on AstraNine focus problems under daylight

There seems to be only one global adjustment for the Kr.

The K5 however has a sensor that scans the light, i wonder if you can adjust that one in a way?

It seems like it's a global problem with the FF so it should be the AF and not the extra sensor that's causing the problem.
How does the 645D preform?

I wonder if the 18-135 will steal some souls.