Problems using aperture ring

Pete, the only reason I was experimenting was that I have an M lens on the way (my first) and just wanted to prepare myself for it. In actual use, my A lenses will stay in the A position.

I'm now a little concerned that these AWB problems will be unavoidable whilst using it.

Ok, you've discovered a strange bug in the camera, but it won't be a problem with a manual lens if you can end up with a WB you're happy with.

Shooting RAW will help as the WB can be changed afterwards with absolutely no detriment.

I understand what you're saying, but if the AWB behaves on the M lens like it does when an A lens isn't on A it's going to be a bit of an inconvenience.

I'm just trying to understand if there is anything I'm overlooking.

Understood. Perhaps you should just avoid AWB with manual lenses then.

Actually I might have experienced the same problem and just not noticed it. I'm used to routinely adjusting the WB so it doesn't bother me when it's a bit off to begin with.

Yes you might have a bit of inconvenience, but it's not that serious compared to the inconvenience of metering you're going to have with manual lenses.

Sorry at the moment I don't understand the cause of the problem. It may remain a mystery!

You're probably not overlooking anything and probably there's just bug in the firmware.

It appears to be that (all other settings being equal) when using the A position and dialling in the aperture on the camera the AWB does one thing, but when dialling in the aperture on the lens it does another.

That's about as far as I've got, although Kris has identified a remedy.

I'm now just curious as to why it is happening!

Is it really that inconvenient?

It's not bad when the Green button gives a sensible result, but it's a bit of a pain when it doesn't. It's worth the inconvenience when you've got a good lens, though.

Cool. Got a 135mm f3.5 arriving tomorrow which I'm looking forward to.

I'm guessing that most of the time the green button (it's not a green button on the K-m, but there is a button that does the same) will give a vaguely sensible result then it's just perseverance when it doesn't!

The answer with the "A" lens is to use it in the "A" setting

I use M lenses all the time and do not experience problems with the AWB white balance, althogh I rarely use AWB these days. it is also worth pointing out that an indoor shot such as your example is outside the range for AWB to work. Your camera may be different, but with the K10 AWB is for daylight shooting only.

What is your camera ?

Metering with M lenses is not straightforward. You can use them in Av but they will expose correctly BUT at max aperture only. In Manual exposure mode you use the green button (may be a different button on your camera)to "stop down" the lens momentarily and take a meter reading, this sets the shutter speed. You can also (on the K10) use the DOF preview (optical) to turn on the meter and adjust either shutter or aperture to centre the meter.

However you will find that either of the manual methods will progressively overexpose as you use a smaller aperture. So you will have to use the histogram check your results and adjust exposure accordingly.

AE-L button for K-m. Yes, you just make a manual adjustment when required. You get to know the quirks. It's not a problem really unless the light on your subject is changing very quickly.

Peter, as I mentioned I was only using the A lens out of the A setting to prepare for receiving an M lens tomorrow.

As for the AWB it works fine when using the A lens in the A setting in that environment (my camera is a K-m incidentally), I've not been aware of any issues with AWB in any setting I've shot in previously. It just seemed to get problematic when using the lens manually.

I've no problem with the metering process (it's the Av button on the K-m in M mode), just the discrepancies that the AWB seems to generate (all other settings were equal in the test shots I took).

Good luck with the M135/3.5 It is a great lens for the price.... so nice to use and excellent results.

I have had mine for 30 years !!

Good to know!

I think it will be a good addition to my A28/2.8 and A50/1.7.

The trio of 28mm, 50mm and 135mm lenses was the entirety of my lens collection for about the first 20 years of my photographic experience!

K.