I suppose, being born in Inverness and staying there on and off for about 30 years, let's me call it, 'My Town'

Inverness Castle and The Flora MacDonald statue, two of Inverness's most famous landmarks.





K10D + 'The Fishy'

Thanks Lilly, I usually manage to get up for the Up-Helly-A celebrations, but missed it this year, did manage to get the picture on to the BBC Scotland News web page. Second attempt at this, was quite pleased.

http://news.bbc.co.uk/1/hi/in_pictures/7257394.stm

Taken in Lerwick while waiting for the 17:00 ferry back to Aberdeen,





K10D + 10-17 fishy

I like these a lot, good to see more things the 10-17 fishy can do.

Note to self :- get off your backside more often John and get images like these - I wish !!!

Thanks for all your replies.

Matt, I think it is 'back-focusing' but not by very much, as it is not noticable when stoped down a bit. I think my messing about with shots at f1.4 has shown it up where it wasn't as obvious before.

I do remember your thread on the subject, and will look back over it.

I am going to look at doing something about it when I get back from Orkney.

p.s. Been in Orkney since Monday, 18th Feb, I was due to come home on Thursday, unfortunately, all sailings have been cancelled until, hopefully, Saturday morning at 10:00am, weather has been so bad, the K10D has never left the 'bag'

The problem doesn't seem to appear on the DS I have John, just seems to be with the K10D.

It's an 'A' lens not an Auto Focus.

I was focusing manually.

The little shiny spot was pin sharp in the viewfinder, but when the picture was viewed, it seemed to have focused behind the rocks.

The bush behind and to the right in the first picture is sharper than the rocks I had focused on. Which leads me to think there is a problem with the K10D "back focusing".

Thanks for all your input people, I went out today hoping to resolve the issue once and for all.

Now I feel worse.

Matt, I know anyone taking landscape shots at f1.4 needs a slap, but creative opportunities may arise where this may be a possibility. In the original pictures I was trying to see the effect of the boat lights with a wide aperture in the dusk.

Anyway, today I went out and shot a few pic's, ( 150 ) , and I am now convinced it is the K10D at fault, not the Pentax 50mm f1.4 lens !!!!!

How did I arrive at this conclusion, well I took some pictures of a 'rocky outcrop' using the reflection from a shiny piece of rock as the focus point.
This 'shiny piece' was very small and provided a definite focus point, fractions either way and the reflection disappeared.
I started at f1.4 and went all the way down to f22, focusing on the 'shiny spot'.
When the pictures were viewed, it was not till about f5.6 that the 'shiny spot' showed up on the pictures, although it could be seen in the viewfinder at all times.

I suspect that the K10D is 'back focusing' a bit with this lens, does that mean it is back focusing with all my lenses ???

Anyway, here a pic or two to show what I mean, the first one was focused on the 'shiny spot', but you can't see it in the picture, the rocks were about 15-20 feet away, so at f1.4 with the shallow DOF, I didn't think I could see Grangemouth Works 3-4 miles in the background !!
The second picture at f8 seems to resolve everything, you can just see the 'shiny spot' centre left on the centre rock. I did move sideways a bit for the second shot, I was a bit close to a 'Richard the III'

I know it's bugger all to worry about, but I do like things to work properly, may down-grade the firmware and get the big screwdriver out and do the adjustments, just to stop me from throwing the K10D away !!!

I still love this lens and I have had great pictures from it, even at f1.4, but as I remember now, that was on the *istDS

f1.4




f8




'shiny spot'

I took about 10 pictures at f1.4, and they all resemble the first picture above. Even with the shallow DOF, it should be sharp somewhere !
As soon as I stopped down to f2.8 and below, the quality improved greatly, even with the resulting slower shutter speed.

I'm stuck in the office in Edinburgh for the next few days, but I'm up in the Orkney Isles next week, so I'll do some experimentation and let you know the results.

I took a walk around Lerwick harbour in Shetland last week and gave the 50mm lens some exercise.

You can see from the pictures below, that the performance at f1.4 was very poor, but very good at f5.6. The conditions were probably darker than they appear in the images, ISO was 800 for both, 1/40 @ 5.6 and 1/320 @ 1.4.
Both handheld using SR.

Both pictures are 'as-shot' no post processing, just reduced in size to 800px wide.

Should I expect better quality at f1.4 or is this typical ?

If people are paying extra for the faster f1:1.4 and f1:1.2 lenses, should they not perform better at these wide apertures ?

f1.4




f5.6