k-5 randomly choosing ISO

Just wondered if this was something anyone else has found, or its just me inadvertantly doing something without realising, but quite often my K-5 goes from auto ISO to a specific ISO.

I tend to have the K-5 at Auto ISO (100-3200). Yet quite often I'll take a shot and go "whooa" and realise its set to a specific ISO and its always one of the highest the camera does (upwards of 6400).

Anyone else have a similiar experience?

(I should also add my previous camera was a K-7, so I was already very comfortable with the K-5 from the outset).

Perhaps when changing ISO something has inadvertently been set in error?

I'm not a big fan of auto ISO because shots side by side would exhibit different noise structure.

The only other explanation would seem to be a fault of some kind.

Clearly I'm hoping its not a fault!

Perhaps the best thing to do is reset it to default and take it from there - see if it continues.

What mode are you shooting in? Have you checked in the menus that you don't have one of the wheels set to ISO - for instance rear wheel for Aperture in Av, and front to ISO? Could be you are accidentally resetting the ISO that way.

Gwyn, that's it!

I did't think of checking the front dial (closest to the shutter button), as I primarily use the rear dial for changing aperture as I'm in aperture priority most of the time.


On the K-7 I forget what the front dial was was set to in Av mode, but it certainly was'nt the ISO.

I feel daft for not realising this. Thanks for solving the riddle.

Just to add: when you have ISO-override assigned to a wheel, you can press the Green button to switch back to Auto-ISO.

The change from Auto-ISO to a forced ISO is also indicated in the viewfinder and top LCD. An underlined ISO value shows it's forced, the "Auto" indicator appearing shows it's in auto (IIRC)

Matt

Useful info thanks Matt. I was indeed using the green button to go back to auto ISO.

I've now reset it to factory and the front dial now does not do anything, which must have been how the K-7 I had before was set up. Must have been catching it somehow.

Hi Bob,
I am glad it's not a fault.

Best Regards,
George

Try TAv Bob, you have control over all three values with just the two control dials and you can see just what is set to what in the viewfinder.

Surely, in TAv mode, ISO is the only variable and is allowed to float. It's only fixed at exposure time. Aperture and shutter speeds are fixed by the two dials.

If you want full control over all three (T, A, & ISO), you'll need to use manual

I must admit that's what I thought too.