M lens functionality on *ist DS: How much?

I think by "stop down switch" he means the fact that you pull the power switch ring towards you to meter with the M lenses, where on the MX and other cameras with the mechanical actuator that Penax stupidly left off the digital cameras, the camera already knows where the lens is stopped down to.

It's not really a problem, but it could have been completely un-necessary if they hadn't crippled the KAF mount on the cameras.


If they make another line of digitals, hopefully with a better name, I hope they put in the actuator so it's a full KAF mount.

I agree that this method works, and has its advantages, but the suggested, and quicker, way is to press the green button on the D or some other button on the DS.

Personally, I rather like this system. When I want the camera to do all the work, I use an AF lens. When I am in a more actively photographic mode I use a manual focus M or K lens and take my time.

The fact that K and M lenses can be used on the latest DSLRs is a great boon. The fact that they don't offer aperture priority metering is, for me, no big thing. They DO offer spot-metering, which is a great improvement on the MX and LX.

Obviously, others will have their own views.

G

I am very leery of the green button; it seems to set the camera into some sort of odd automatic mode where you're not too sure what's going on.

I guess I'll try it again and get used to it, but I tend to avoid mysterious automatic gizmos.

OK, I tried the scary green button. It basically means you can operate the M lens in apeture priority when set to Manual. Very convienient!

Thanks for bringing it up!

Arthur,

It's not really aperture priority, because it doesn't update itself when the light changes. It's actually exactly the same as adjusting the shutter speed on a manual camera in order to set the correct exposure. If the sun goes behind a cloud, you have to re-do the process.

But as I said before, it's a bit quicker than fiddling with the shutter speed dial until the needle is in the right place. So it's equivalent to using an MX, but faster.

By the way, what is the "42" for at the bottom of your posts? Are you a Spotmatic man?

G

I would guess that the 42 is the Ultimate Answer, to Life, The Universe and Everything.

The question is, of course, what do you get when you multiply 9 by 6, hence the thought that there's something fundamentally wrong with the universe....

Arthur Dent's location may have also provided a clue George! But then I didn't get it either. I thought it must be his age, sorry Arthur!

I have recently begun to use a K 30/2.8 on my *ist D. I had initially dismissed using K and M lenses as being 'fiddly' and cumbersome compared to the modern high-spec nature of the camera itself, it was just a feeling. Yet now, I think I understand the *ist D a little more and have grown acustomed to it I find myself using it more and more like an older manual camera, I'm even using a separate light meter at present. It could be a phase I'm going through. . By the way, I am really appreciating the 30mm.

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...and I thought it was "Sector Z-Z-9-plural-Z-Alpha"
Or is my memory going?? I feel a Marvin moment coming up!! LOL!

Sorry, never having read the Hitchhiker's Guide the literary allusions were lost on me. Must get round to it sometime.

G

It actually works just fine if you are counting in Base 13 instead of Base 10. But perhaps Adams had three extra fingers?

MattMAtic: You are right, I'll see if I can change it. All that wandering around sometimes gets me confused!!

So that's why I used my trusty MX cameras all these years. Some planets don't have the same kind of batteries that we do.

George:

The Guide actually exists, see http://www.bbc.co.uk/dna/h2g2/

Also see http://www.bbc.co.uk/radio4/hitchhikers/game.shtml

Hey, thanks for the links. I remember playing the original Infocom game

So I found myself on this mathematics forum, reading all about base 13....

Fascinating, so thank you Arthur for the added insight!

Another discovery: Put the old M lenses on the camera, set to apeture priority, and pull the ring to the DOF position just before shooting. Apeture priority!!

OK, kids here are the hard results of a controlled test. Firmware version 1.12.

Meter operating time set to 30 seconds, in custom functions.

Format set to RAW

Focus selector set to Manual (it's an M lens, after all)

Mode set to Apeture Priority ("Av").

50mm f/1.4 Pentax-M lens set to F/4 on apeture ring. That's three stops down from the fill open apeture

Initial reading taken in one light level, camera moved without re-testing while shutter speed varied in viewfinder display.

Subsequent photos taken during the 30 second meter operating period in different lighting levels.

Results:

All frames werre correctly exposed. Shutter speed ranged from 1/2000 to 1/6 second, lens was left at f/4.

This seems to indicate that once the camera knows what the lens is set to, the shutter speed is set accordingly, and the lens closes to the selected apeture.

So you can basically use old non-automatic lenses in apeture priority mode, Pentax has pulled off a slick save and redeemed themselves (partially) in the eyes of professional and enthusiast users.

If you're monitoring these forums, Pentax, put the full KAF mount into the next series of DSLR's.

And put in pixel mapping, it's a big selling point on the Olympus cameras and the strategy works. You could even license the dust removal from Olympus and have the most usable DSLR in the industry!

In case of any doubt, there is an adapter for K mount lenses (and many others) to fit them on the Olympus DSLR's. Olympus was smart when they chose the back focus of the four-thirds system.