[Spock]

Does anyone know if the Aperture Info Record can be set up to work in 1/2 stops instead of full stops?

Thanks in advance.

[Ishpuini]

You mean the aperture you can set for manual lenses without auto aperture setting?

I think it's full stops only unfortunately. There's only the 1/2 or 1/3 Ev stop option that works on the all exposure parameters coming from the meter, but not on the manually set aperture...

Now, most of these lenses in my collection have mostly full stop click stops throughout their aperture range. The only exceptions are the wide open positions on some. Most important here is my K50/1.2 that has f/1.2 and an unnamed opening (f/1.7?) before f/2 and the rest of the full stop series. That is a lens I often use (near) wide open, in which case I just set f/1.4 for both these... Most others are used stopped down, so it's less of an issue for those.

[Sakura]

I just happened to have the 50mm 2.8 pancake lens on my desk. From 2.8 to 4 is a one click then the scale goes to 5.6-8-11-16 all with a 'in between' click. Then to 22 is again one click.

[Ishpuini]

Indeed, those are half stops. It would be nice to be able to select these indeed. But OTOH does it have to be that exact? One stop accuracy is much better than what we had before, and the more accurate the steps can be set, the more clicks will be needed to input the data. Let's not forget this is for documentation purpose only.

Since the lens is not recognised by software by lack of identification, there will be no profiles that will be applied automatically taking into account the aperture for instance. Unless you would painstakingly generate a profile yourself that you would select/apply manually in PP. Probably half a stop off would hardly impact the effectiveness of such profile, esp compared with a situation that cannot distinguish aperture at all.

One of the things I find very useful is learning the sweet spot aperture of a lens while reviewing on PC, which I could never do unless I documented in a notebook.

[Not a Number]

I believe the @OP is referring to the new function on the K-3iii to manually enter in what F-stop was used in to the EXIF data much the same way focal length is entered for manual focus lenses lacking an "A" pin connection. See page 118 in the user manual.

If there is a click stop between numbers on the aperture ring they are usually 1/2 stops. The exception would be the first click on lenses with a maximum aperture that is more than one stop to the next labeled stop, e.g. f1.7 to 2.8 on the SMC-A 50mm f1.7 lens).

Not being able to add a 0.5 decimal seems an oversight and perhaps can be changed in firmware.

[mtkeller]

I believe the @OP is referring to the new function on the K-3iii to manually enter in what F-stop was used in to the EXIF data much the same way focal length is entered for manual focus lenses lacking an "A" pin connection. See page 118 in the user manual.

If there is a click stop between numbers on the aperture ring they are usually 1/2 stops. The exception would be the first click on lenses with a maximum aperture that is more than one stop to the next labeled stop, e.g. f1.7 to 2.8 on the SMC-A 50mm f1.7 lens).

Not being able to add a 0.5 decimal seems an oversight and perhaps can be changed in firmware.

As @Ishpuini says, I’m not sure how critical it is to be able to record in half stop increments. If it could be done via a FW update and be independent of the step size (1/2 or 1/3 stop) you have set for lenses where the camera controls the aperture, I would welcome it. If, however, I had to put my camera into 1/2 stop increments to match what the camera can select to what the lens offers, then I’d rather not have the additional granularity.

[stevebrot]

Not being able to add a 0.5 decimal seems an oversight and perhaps can be changed in firmware.

Does it not accept half stops (I think 8.5 is the only 1/2 stop aperture value that is .5) or is there a general restriction on other than full stops?


Steve

[mtkeller]

Does it not accept half stops (I think 8.5 is the only 1/2 stop aperture value that is .5) or is there a general restriction on other than full stops?


Steve

Rotating your aperture e-dial with a manual lens can only set full stops: 1.0, 1.4, 2.0, 2.8, 4, 5.6, 8, 11, 16, 22 and I haven’t bothered to turn the e-dial beyond that.

[Spock]

The lenses I'd be using the manual aperture input for all have half stop clicks. I hope pentax will fix this with a firmware update. It wouldn't slow input because it's easy to spin the aperture dial fast just as when used in hyperprogram aperture priority - in which I've always used 1/2 or even 1/3 stop steps.

[mtkeller]

Right, our lenses have half stop clicks (and sometimes a mix of half and full), but how many of us dial in third stops when using modern lenses? They’d need to support manual entry in half stops while letting us stay in third stops for modern lenses. Or just leave it at full stops and say we’re close enough. I see this as a feature request, not something wrong to fix.

[Ishpuini]

Right, our lenses have half stop clicks (and sometimes a mix of half and full), but how many of us dial in third stops when using modern lenses? They’d need to support manual entry in half stops while letting us stay in third stops for modern lenses. Or just leave it at full stops and say we’re close enough. I see this as a feature request, not something wrong to fix.

I for one wouldn't have a problem with half stops being applied overall, since one of the first things I change on a camera is going from 1/3 stops to 1/2 stops. I find 1/2 stops accurate enough to set proper exposure and faster to dial in larger Ev corrections. But I fully understand that most people prefer to keep their camera on 1/3 stops, so it would not be a good idea to sync the steps for actual Ev settings and for manual aperture entry, since 1/3 stops wouldn't match old lenses either.
But, really, I still haven't seen any reason, other than accurate documentation, why one stop accuracy would not be good enough.

[Spock]

I'd be happy with 1/2 stops steps. And if the feature was added in a firmware update, the full stop option could easily be retained.