I've found SR better when using relatively short exposure times. When using shutter speeds longer than about 1/10s there may be gradual, incremental errors within the SR (it's having to translate a sensed movement into corresponding CCD shift - any small errors will accumulate).

However, when using telephotos the SR comes into its own. I've managed a pinsharp handheld shot at 1/50s with a 500mm lens
Matt

Will,
I think I have access to a Canon 580, so I might measure up
The other people to ask are the people who do Omnibounce - they have measurements for practically every flashgun out there...
Matt

Daniel,
I suspect they meant 3000mcd white LEDs
And it probably is up to that distance. LED light doesn't go very far - it's certainly no substitute for a proper ringflash.

The other thing I saw this week was on ephotozine:
http://www.ephotozine.com/news/fullnews.cfm?NewsID=3732
and http://www.ringflash.cz/en_eshop.php

Sounds an interesting idea and I like the results. Has me thinking though...

Matt

Pete,
Most modern zooms are not sealed. So when you zoom in and out the air has to go/come from somewhere - and it's this process that can suck in dust.
Additionally, the cameras are not produced in cleanroom environments - they are shipped minus the lense and so at any point there could be some dust in the chamber. It might be shipped with dust on the CCD already, or internal dust can be dislodged during use and find its way onto the CCD.
Matt

I always have dust. Lots of it.

On the *ist-D I had platefuls of it and even with careful cleaning it seemed to creep back in. Having seen Keith Henson's CCD (ephotozine user "keithh" on his Canon 1DsMkII I don't worry so much - his was the dustiest sensor I've ever seen Just takes a minute to clone out with the patch tool in Photoshop.

Anyway, back to the K10D - my current process is:
1. Try the built in dust removal that shakes the sensor. This works most of the time.

2. Use the sensor cleaning option (which allows manual cleaning) and blast with a rocket blower. Don't use canned air. This got rid of my dust spots (which were larger than your example).

3. If all else fails - I'll use the manual clean. Pentax sell a kit for this. I've used other kits for the *ist-D and *ist-Ds and it's not that difficult, just nerve wracking the first time But, so far, my K10D hasn't needed this.

I've heard of people saying they have never had dust at all But my personal experiences say you can never get away from it 100%, and at the end of the day a single spot is no big deal in Photoshop or Elements

Matt

Pete's post is available here: https://www.pentaxuser.com/forum/viewtopic.php?t=3797


To answer your question - it depends on the type of dust

Some dust is stickier than other dust, and some of it will require a physical clean (the old fashioned way).

But compared to my ultra spotted *ist-D, the K10D is practically dust free!
Matt

Now you sound like my kids
Matt

Erm, errr... yes, that's the theory
Been meaning to get around to it - but I'm so tied up at work just now
(Keep pestering me and I'll get a quick guide done sometime... I hope )
Matt

Rodger,
If you take a look over at The Light's Right Studio they take a very good approach to sharpening.
There are three stages:
1. Capture
2. Creative
3. Output

Capture sharpening should just give a little "bite" to the image, trying to undo the softness caused by the Bayer colour filter over the CCD. In Silkypix, for instance, you'd want something like "Natural Fine" taste for the K10D - nothing major. There should be no halos or obvious sharpening at this stage.

Creative sharpening is where you want to highlight particular elements. For instance, in portraiture I'll often do extra sharpening around the eyes (by duplicating the layer, slightly oversharpening, and then using a layer mask to control exactly how much and where).

Finally, Output sharpening is designed to get the best possible result from the intended medium. If it's for web, I'll use something like USM at 100%, 0.5 radius, 0 threshold (after having resized it to 1000 pixels). For inkjet print you need to oversharpen so you can see the halos at 200% view.


Just bear in mind that once you sharpen it's hard to undo it. As a consequence, I tend to keep the original capture-sharpened image as the background in Photoshop and duplicate onto a new layer for further sharpening. I'll save the PSD file with layers (which can be 150 to 200Mb with the K10D and the kind of editing I do), and then flatten and output sharpen for each type of print (remembering NOT to save and overwrite the original PSD file )

BTW, the link is: http://www.thelightsrightstudio.com/tutorials-pdf.htm
You want the PDF "Put a Fine Edge on Your Sharpening Skills" - there's the PDF and a learning gallery too.

EDIT: Just crossing the ether... sharpen a little in Silkypix, sharpen a little if you use Adobe's Camera Raw to open the DNG. Follow with any creative sharpening you want to do. Then flatten, resize and sharpen for output (and as you say, don't do any further editing on that version of the image). I would always apply a little discrete sharpening on opening the DNG for the reasons I outlined

Hope that helps!
Matt

Just a point or two...

From what I've heard the *ist-D was designed to focus at the hyperfocal point automatically... and I've often wondered how it manages to do this as it'd have to know exactly how much to move the focus mechanism for each lens.

Of course, all Pentax lenses have a lens-ID which is communicated to the body - but if you inspect the file with the Pentax Browser (which shows the lens model from the EXIF data), then the third party lenses are often wrongly labelled...

I had this issue with a few Tokina ATX lenses I had from the Z1 which never seemed to give a clear image when compared with the results I obtained from film.

Whether this is the problem, I don't know, but it may be worth bearing in mind

(The K10D does seem more accurate at focus though, and hopefully they've dropped the hyperfocal focus function.)

That said, I'm sure others who have Sigma gear will be able to shed some more light

Matt