Not me, Gartmore I believe.

I was in Cameraworld in Chelmsford a couple of weeks ago, and a gentlemen came in to ask about a new lens as the one he had was so soft, and he thought a newer version with image stabilisation might be better.

I did a few test shots with it, camera on the desktop, pointing at some text on camera boxes 20 feet away, and it was barely readable wide open, but somewhat better stopped down to f/11.

After a bit of head-scratching and more test shots, we noticed there was a Jessops UV filter on the front. Took that off and the lens was far sharper wide open than it was stopped down with the filter on. Saved him the cost of a new lens.

Dan

Good news indeed! Now just make sure you have at least two copies of everything.

Dan

I think you'll find it does. Have you been spending too much time in the sun?

Dan

I can happily listen to any Elbow album on repeat and never tire of them.

Dan

Why not get some holidays out of it?

The Empire State Building
That Norman Foster bridge in France
The Sydney Opera House



Dan

James, now that you've decided on what you're doing, can I offer a suggestion?

There's a direct and measurable health benefit on the human body from exposure to nature, even in the form of pictures, or views through the window. For a doctor's surgery, I would be inclined to utilise this effect and choose natural subjects, such as flowers, trees, landscapes, skies etc, giving you a whole range of colours to choose from, yet with a health benefit too.

Have a read of this journal, or at least the first page or two, and perhaps reconsider your subjects? If you can promote the health benefits of your photos, backed up with evidence, you may be able to get further commissions from other doctors...

Dan

The unusual distortion pattern with the sigma (compared to the Pentax) is not to do with perspective, but simply that between 10 and 12mm there is distinct barrel distortion but only at the corners of the frame. So at 10mm you might see a curve on the ends of the horizon, which is harder to correct than if it was a continuous curve over the length of the horizon.

Here's an example:


*istD, Sigma 10-20 @ 10mm

What irritates me a bit is when people say the Pentax 12-24 shows less distortion at the wide end, and is therefore better. As the Sigma loses this distortion by 12mm, it simply offers 2mm extra wide-angleness if the need arises, and a lot of the time the distortion isn't noticeable then anyway, depending on the subject. That wasn't directed at you Simon, it's just something that is often quoted.



K10D, Sigma 10-20 @ 10mm

This thread has some more discussion about it (although I'm sure there are plenty of them on the forum :lol, including a quote from photozone regarding the respective distortion patterns and other merits.


Dan

Not quite the same, is it?

I think the way the way the focus ring keeps moving is something to do with the quick-shift, but I could be wrong.

Dan

Sounds familiar...

https://www.pentaxuser.com/forum/topic/100mm-dfa-macro-new-purchase-20306



Dan

I've just googled and found flights from London to Sydney for less than £500 - I'll see you in 24 hours!

Dan