We all come at this from our own perspectives I can see! In my case, I am getting my best shots printed at 100 x 70 cm for wall display. I simply must maximise whatever 'qualities' I can muster from my camera and lens.

I say 'qualities', because its not just about 'sharpness' (which I personally feel could be achieved in a variety of ways for any given output size - you can make pictures 'sharp' with many different editing techniques) - but things like vignetting, distortions and abberations are affected by F-stop settings surely?

In my case (yes, I only have a K7), for the printed sizes I mentioned, I don't want to capture any noise if poss, and I certainly don't want to introduce any signs of noise reduction processes going on also. So I need the lowest ISO I can shoot steadily at.

Apart from my Samyang 14mm (the only lens I possess that might approach the 'pro prime' designation) my lenses are more standard, and at my output sizes I'll be seeing a falloff in IQ particularly at the edges if I started shooting wider than f 8.0.

Reagarding Tav mode (where the camera sets ISO following user set Av & Tv), this is obviously useful when a particular aperture (say for quality purposes) and shutter speed (say for movement depiction) are needed - this would be a rare occaision I hazard to suggest

But surely we should be cautious in this mode, as even with our modern K5s the variation in quality as the ISO shoots up is surely greater than would be seen if the aperture were to open up instead ?? (Smeggy, this is a hint for you to post the 'Rasta Alien' image again)

At least the lesser experienced of us should be wary of introducing noise into our shots that may be missed on the LCD, but be disappointing when printed out. Is it not good advice to suggest that we should aim to keep ISO's as low as practical in the available light, in the interests of the best quality?

If we're talking about image quality, and I'm guessing that's what Peter was referring to (ie lens performance) then I do think it is fair to say that 'the consensus' is that there a 'sweet spot' for lenses generally, at least for anything below professional-grade primes, certainly for zooms, and this is very often placed at f8.0.

Certainly from most photography books or mag articles I've seen over the years this does seem to be a reasonably consistent idea. Put it this way, if your main consideration is extraxcting the highest 'quality' (in scientifically measurable aspects) then f8.0 for most lenses would be a good starting point - is that not fair to say?

Of course if DOF is the main reason you are choosing a particular aperture, then you are stuck, either with a compromise (on a lower quality lens) or possibly less compomise ,if you're lucky, on the highest quality lenses. But DOF is not the only consideration in choosing aperture. Finding that 'sweet spot' may well be desirable as well.

Our Cameras have the MTF program line function (when shooting in P), to
automatically aim for the optimal aperture (on DA lenses ony) - I'd hazard a guess that f.8 might feature in this mode fairly often - maybe you could test this Peter?

There are a couple of metering aspects which might be affecting things also. For a number of subject types switching to 'Centre-weighted' can have a significant effect.

But there is a menu item that links the active AF point to the exposure system more directly - on my K7 it is termed 'Link AF point to AE exposure', something like that. For average toned subjects activating this function will have the effect of slightly brightening exposure, as any brighter outer areas are given less weight in the exposure balancing. You may find this helpful and you may not need permanent + EC.

No, I'm cetainly not suggesting we don't copy files to a computer (although wasn't there a member in a thread a while back who did actually keep all his shots on cards and never copied them ?)

I was referring to my understanding of some 'best practice' guidelines that I have always been aware of and adherred to - that is that SD cards are less likely to fail or cause any data corruption to files if the amount of copy / move / write / delete operations was kept to a minimum.

My own 'best practice' then is to use a larger card to capacity prior to copying to the computer, then backing up to an external drive or DVDs before formatting the card in the camera ready for reuse. The larger the capacity card the less number of times you will be copying and formatting it.

I definately don't want to be encouraging any 'internet hearsay', but I believed this advice was fairly commonly given in digital photgraphy references and guidebooks. In any case, I am glad that repeating it here has generated the more technical responces we have had - maybe such advice is out of date, being more relevent to earlier generations of cards?

I am always delighted to be corrected by those with more technical experience, but is is not true that a card where the files were deleted on a computer and then not re-formatted in the camera was potentially more at risk of having failures when shooting?

I think for any system the most versatile and controllable approach is full manual. This eliminates any variables caused by the camera and its interaction with the flashgun and the inconsistencies and innaccuracies caused by the 'through the lens' flash metering, which can be negatively influenced in the same way as the ambiant light metering, as well as by reflections and flash hotspots causing underexposure.

Manual control allows better balancing of flash and 'background' light as well. There will certainly be many more expert people here who will understand the specific functions your Pentax unit offers, but for manual work you really need a distance readout scale, or LCD indication of the correct subject distance.

You firstly set the ISO and aperture on camera, then either repeat these settings on the flash (or confirm the flash has read them from the camera), then read off the correct 'flash to subject' distance from the flash display. If you cannot get far enough away for this distance, then you have two options - either stop down the aperture further, or reduce the flash power (eg 1/2, 1/4, 1/8 etc.)

Your choice of which to do would really depend on whether you had a need for a specific aperture for a depth of field effect. If you didn't want to stop down then you must reduce the flash power to achieve the correct flash exposure. Different flash models will have different means of displaying the required information.

For Fill flash use, you would want to reduce the power more than recommended for correct flash exposure (say half or so), also by stopping down or reducing power further, again depending on the subjects need for any particular aperture. I do feel this approach will ultimately give consistent and more precise results than any automated TTL system.

I have a K7, with the firmware updated, and I successfully use a 32gb card (a Duracell one, been great so far).

I find this capacity very practical as I mix photos with video also, especially if out with the family. The videos files from the camera are large, so starting out with 32gb gives plenty of leeway. I've been fortunate not to had any card failures in my 5 years of using digital (so far).

I have read and heard that it is best to limit the amount of copying and moving files from the card to another device, at least to keep this to a minimum, and also not to delete files on the card using a computer, but rather to format the card in the camera before reusing. So this is another good reason to use large capacity cards.

Its certainly true that a RAW converter (like PDCU) and a pixel image editor (like Photoshop / Elements) work well together.

Photoshop & Elements also offer us a RAW 'Front end' with the Adobe Camera Raw plugin (ACR), which applies 'parametric' edits to a RAW image, altering key aspects (White Balance, exposure, vibrance etc) and then 'export' this work into the main interface of the program as either a JPEG / TIFF / or PSD file. This is then further worked on at the pixel level, or better still, more non-destructively using the enormous flexability provided by the layers system.

PDCU offers editing controls that are significantly aligned to the actual Pentax on-camera image controls, and gives a greater and enhanced degree of fine control than you get if just using the menus on the camera.

Lightroom is a different kettle of fish altogether - it is what I would term a 'Cataloging Parametric Image Editor' (yes, I do love these big terms !). But it is helpful to categorise it.Other examples of this type of software would be Apple Aperture and Bibble Pro.

Firstly, it provides an integrated file import and management database (the Catalogue), which creates a stored cache of thumbnails based on system folders it monitors and which updated 'on the fly' when the program is running. And secondly, it applies the 'parametric' aspect of editing (ie slider adjustments stored as metadata to be rendered out to an image file) throughout all the editing steps, giving a greater 'non-destructive' basis than Photoshop. This is achieved by the image being held in various states and stages in system memory during each editing session.

It is getting very hard now to clearly advise people on what software is 'best'. It mostly depends on where you are starting from - in my case I have a well established standalone Cataloging program (iMatch), so don't need the database aspects of Lightroom, and I enjoy using the Pentax PDCU converter and like the output I can get from it. Also for some images I need the extra precision and flexability that layers provide, so I use Elements 9 which gives all that I need in that respect.

Elements on its own ? The main part of the program has a lot of the most important parts of full Photoshop at a bargain price, but you may find that the image management and purely RAW conversion aspects are more limited than you would wish.

Absolutely! Set your DSLR to JPEG capture, press the shutter, and instantly your camera has produced a fully post processed / manipulated / edited image. Hopefully it will look OK, but that depends on all the presets and custom adjustments you had to set up before shooting, and of course most of the fine control is taken by the (tiny) camera computer using generic preprogrammed algorithims.

Personally I prefer to be the one in control of my shots, and this means turning to RAW and the computer. Its part and parcel of digital photography now - there is no such thing as a 'real' unprocessed digital capture, IMO.

The Sensor Shake Reduction feature on Pentax DSLRs really comes into its own though with video - gives a lovely 'floating' feel. General non photographers looking at my 'home videos' all comment that it looks 'professional' - (it most certainly is not !!!) but its a good first impression.

The SR combined with a prime lens is a combination hard to beat that may be even more significant than bit rates. I'd agree also that stereo audio through an attached microphone is a must too, and the K7 / K5 offer this.

Capture file formats is a whole new big topic - the avi's from the K7 are fairly hefty size-wise, but I must say on Windows they run well, and I have found editing the files in Sony Vegas Movie Studio Plat11 to be an absolute breeze. The output format will vary anyway depending on purpose, and I havn't had any issues in the conversion from the rather non-standard capture resolution and a more commom one on output.