Hi Jonathan

I also have both cameras and could do the tests if no-one else has or cannot do so for whatever reason. Unfortunately I live in the back of beyond with minimal light pollution but could try to photograph my house from the outside with lights on internally if that would be of any use.

Regards

Eoin Hanley

Hi John - guessed that was the case but I now have the upload control for the monthly which I did not have before. Many thanks

Eoin

Good evening All
I have just uploaded an image into this week's Darkness topic. Actually I wanted to upload 2 but now cannot find the 'upload image' control for either the weekly competition or the monthly competition, which I have not yet uploaded into.

Clue please?

Many thanks

Eoin

Hi All and thanks

John - I always understood that the proper term was, as you pointed out, depth of field but I remember a posting from a few months ago which stated depth of focus - but I may well have remembered incorrectly.

Thanks for the 2 links - not quite what I had hoped but lenses are complex so I was expecting too much.

I recently got the Sigma 150-500 and was surprised by the shallow depth of field at f/6.3 when photographing birds at relatively close quarters (10 metres). Obviously I can easily go to f/8 or beyond but the speed suffers.

I believe that I will download Defragged's calculator and see if I can derive some simple tables for the lenses that I am likely to use on safari in South Africa in 3 weeks time.

Now all I need is an answer to my other post about the continuous autofocussing on the K5II

Regards

Eoin

Does anyone know of a simple(ish) formula which would allow me to calculate the probable depth of focus from the distance to the focus point, the aperture setting and any other item that would need to be factored in? Or is the calculation either too difficult to be done with mental arithmetic or does the depth vary from lens to lens and therefore not easily quantifiable?

Regards to all

Eoin Hanley

I was fortunate enough to be able to swap my 2 * K5 for a K5II and a K5IIs recently. However, I am not happy with the continuous autofocussing either in spot mode (focus at the centre) or in SEL mode where one of the major advantages of the K5II is supposed to be the intelligent tracking of a moving object. Generally I photograph wildlife but I could just as easily be tracking at motocross. Has anyone else had the same problem?

On the K5 in AF.C there was a constant aural feedback as the focussing altered. This appears to have gone on the K5II.

Is there a setting that I have missed? I am on the latest version of the software, I believe, 1.04.

Regards to all

Eoin Hanley

Hi All again

Apologies for the silence - I have been away. I have spoken with Sigma's technical department who do not inspire confidence. After several totally incorrect answers, they have confirmed what you have all said but seemed quite disinterested in updating their website to show the correct teleconverter pairings.

Perhaps a move to the dark side is called for especially if the best that Pentax can come up with for Photokina is a full frame camera.

Regards

Eoin

Hi Mike

Many thanks for the constructive info.

For the second time (at least) this morning I am confused because I have just been onto the Sigma Imaging site and their compatibility list for teleconverters/lenses definately shows that the Sigma 70-200 APO DG HSM has full auto focus in the Pentax mount. What am I misreading or missing?

Eoin

Hi George - I have just noticed and commented on your 2x in the classifieds.

I am unsure about your last 2 sentences. The 'it' that is neither used nor needed is the DA300* or the convertor?

Would the IQ of the 70-200 used at 150 with 2x converter (i.e. 300) match that of the DA*300?

Regards

Eoin

Hi there George

Is the Sigma 2x teleconverter still available?

Eoin