I too have had the issue a few times in the last couple of months

It has happened to me with partially charged batteries. Pressing any button flicks the mirror up and down, and even powering off does the same

Generally, powering off for a while will stop the issue (at least temporarily). Removing the battery seems to stop the issue (and I don't believe it's down to freshly charged batteries - happened to me with a battery I'd been using for several days of on and off shooting).

EDIT: Tried cleaning the contacts; removing battery (which I have two originals). Have K5 and DA*16-50 on most of the time.

Since I've been through a few firmware upgrades, I decided to reset all custom functions and settings, remove the battery over night and try again. ...the jury's still out... but it hasn't happened yet

Just for the record.... what firmware do you have? (Hold the MENU button down while powering up to check)

Matt

Just to reiterate...

The Bayer filter is there to 'see' in colour.
Then the AA has to be added to reduce the effects of moire that are created by using the Bayer filter.

With all these options I can see that there could be issues when working in JPG in camera.
But anti-moire algorithms are much more powerful running on the PC...
...so it's ideal if you shoot RAW only

Matt

I wonder if the increased resolution has more to do with the anti-aliasing filter than the Bayer matrix... ?

For example, this company removes the AA filter from the D300:
http://www.maxmax.com/nikon_d300hr.htm
Nikon now provide the D800 without the AA filter too.

Some Googling shows that others have removed the Bayer filter from Canon D30 and the like.

Not sure how strong the AA filter is in the K5, or whether the Bayer filter can be removed?

£6k does seem a bit steep though
Matt

Chris,
The PEF format is not in AdobeRGB
All RAW formats (not just Pentax's PEF) are in a colour space of their own - the native space of the camera.
It is the RAW convertor that specifies the target colour space of any image, and you can choose what you like!

That said, there is also an embedded JPG within the PEF RAW file. The colour rendition is dictated by the choice within the camera (e.g. Vivid, Natural, Portrait etc), and the colour space is likewise specified in the camera (either sRGB or AdobeRGB).

But, most RAW Converters (like Lightroom, Adobe Camera RAW, Silkypix etc) ignore the embedded JPG completely and work just from the RAW data.

As to which colour space to use... a general rule of thumb:

* If you don't know much about colour spaces, or are using web graphics, or are giving stuff to others - use sRGB

* If you are primarily targeting print (and especially offset litho for press work), then AdobeRGB is a good choice.

* If you are going to throw the image around a lot in Photoshop, then ProPhoto with 16-bits per pixel is a better choice.

In the latter two cases, you will always need to flatten and convert to sRGB before outputting for web or online print services.

Hope that helps a bit
Matt

You can always extract the embedded JPG from the RAW
(And that's where the image mode helps)
Matt

Stan,
I normally use a 'Rocket' blower

EDIT: Pentax User have one such on sale here!

When using such a blower, make sure you pump it hard a few times before using it to blow off the crud in the camera (otherwise you can end up blowing more dust onto the mirror & screen).

Whatever you do, don't touch the mirror... and preferably not the focus screen either (as they're easily damaged).

Matt

It's possible that it won't work... I've just been testing my K-5

Put the camera in M, 4" exposure, and put a multimeter on the hotshoe (set to ohms, ground on the edge of the hotshoe, and the positive on the centre pin).

Pressing the shutter shows 10M-Ohms (yes, mega) with my Fluke digital meter. You see, the effective resistance will depend a bit on what voltage is applied by the flashgun. The hotshoe pin is 'applied' all the while the shutter is open (giving the flashgun the opportunity to decide whether to trigger on leading or trailing curtain).

You also need to check the polarity of the flashgun The centre pin should be positive with respect to the edge connection Anything else won't work - and can potentially pop the flash

Miranda may have made assumptions about the hotshoe resistance - as I mentioned before, all the film bodies use mechanical very low resistance 'shorting'. It depends on how the trigger electronics in the gun were made.


As I mentioned before, you can do a quick check on the flash gun by shorting the edge-to-centre which should give a flash

HTH,
Matt

Just to check - is this the Pentax dedicated Miranda 700 CD (I believe they did other dedicated versions!)

(You should be able to manually trigger the flash by shorting the centre pin to the edge connector on the flash's hotshoe. Though be aware that the dSLR does this through a thyristor and not through mechanical linkage as was the case when the Miranda was first designed!)

Also, do you have any other flash you could try on your hotshoe - just to eliminate a camera issue?

Matt

It's not just down to monitor calibration, or which colour space you actually work in

You see the RAW processor you use has to apply a conversion from the camera's colour space (which won't be anything 'standard'), and oftentimes this colour mapping can yield wildly different colourations compared to the in-camera JPG.

For example, Silkypix DS has a set of very good (IMHO) colour options to render the scene in different ways.

The only sure fire way to absolutely nail the colours is to perform calibration on the camera and RAW workflow as well! (It's only really necessary to do this for product-colour-matching etc).

As an example, QPcard do a little package - QPcard 203 that includes software to perform dSLR calibration.

Of course, you then have to calibrate your monitor as well... and then probably your printer... and it's getting extremely expensive and very geeky

Matt

Since they specify the max shutter count, I would be surprised if it was honoured. Surely, there would be a case of 'use outside the warranty'.

A similar example would be a car warranty - they specify the number of miles within which the warranty is valid.

You could always phone Pentax and ask
(But if it's not covered, then a replacement shutter is going to be a very expensive option!)

EDIT: This link has a database of alive/dead for several cameras

Matt