The JPEG embedded in Pentax RAW files is approximately equivalent in size to one shot on "medium" quality at full resolution.

John is right of course, and indeed some lenses are intentionally vari-focal to allow the lens designer to concentrate on pure optical quality at the expense of ease of use. The Pentax FA 24-90 springs to mind, along with some of the early Vivitar Series 1 lenses.

I wouldn't be so sure John, I have an original Asahi Pentax adaptor and consistently have to set +1 stop compensation to get proper exposure with my M42 lenses (film, DL2 and K10D so it's not just the K10D acting up)

I think it's just a hazard of the territory with M42 adaptors in general, the slightest imperfection and they mess up the exposure.

It's annoying but you just have to get used to your adaptor and dial in the compensation. I have the User mode on my K10D set to the correct compensation for my Zeiss Flektogon 35mm M42

one other benefit of UFRAW is it can be used as a plugin for GIMP, allowing you to open PEF and other raw files directly in GIMP.

I've never understood the point of view that Tv is particularly useful for fast moving subjects. If I want maximum speed, I go for Av wide open, that way whatever happens I know I'll get the fastest speed the light allows.


But then I also grew up with an MV which only had Av mode, followed by an MZ7 which has quite clunky body controls and aperture ring support so I used Av a lot there too. I tend to forget Tv exists TBH.

when did that happen?

do I get a light sabre?

Most SLR lenses are true zooms, so the focus doesn't change with zooming. For example, my 16-45 is tricky to focus at 16 because of the massive depth of field, so I frequently focus at 45 then zoom out to compose.

Bridge and compact camera lenses tend to be vari-focal rather than true zoom to save space, hence the camera needs to re-focus as you zoom.

you forgot square sensor!

personally, I think it's going to have a built in coffee maker

What flavour of linux are you using?

I use Ubuntu Linux on my Desktop, Laptop and EeePC and find it to be very capable indeed.

I use:

GIMP for photo editing:- If you you're used to Photoshop then the interface will seem a little odd at first, there is a version called GIMPshop which is supposed to have a more Photoshop-like feel, but I've never used it and I don't know how up to date it is. GIMP 2.6 is MUCH better than earlier versions.

RAWTherapee for RAW conversions :- This isn't "free software" in the freedom of speech sense, but it is free as in free beer which is good enough for me. UFRAW is also quite good and is free in both senses. It is less polished though and I find its output isn't quite as good (that's nitpicking, both are very good!). UFRAW has one major advantage and that is when doing Astro photography work. It can take a dark frame PEF and subtract it during the processing step which saves a lot of time in the field because you can turn the in camera dark frame subtraction off.

ArgyllCMS with my Huey for monitor profiling :- it's basic and command line driven, but it seems to work

NeatImage through WINE for noise reduction :- WINE allows you to run Windows software on Linux. It can be picky and works better with simple apps but it works flawlessly with Neat Image. There is also NoiseNinja which is available as a Linux native program, but Neat Image's free mode is not particularly crippled so I use that.

Thats about it really

nice work Bob,

Very interesting that essentially the entire DA* range can handle a bigger sensor than it is currently marketed at. Pentax are clearly keeping their options open, very wise in my opinion.

Edit: I've just decided that what I originally wrote is actually wrong, appologies