[AntonV]

Since the rumor came out about the Pentax K-01 mirror-less with K-Mount, I've been really excited to jump to digital. Im still using my Pentax MX, but quality film processing is getting to expensive & inconvenient for me. I've always known that I would be purchasing a Pentax digital body, because I love my K-mount lenses. I'm just trying to make things less bulky when I'm in the photo mood. The K-5 is not the direction I want to go.

My main question is:

How will my manual lenses work on a digital K-mount camera, particularly a mirror-less design like the K-01. I've never used an autofocus SLR before, so I don't think I'll be missing that function. I'm concerned if photos wont come out properly because the camera cant acknowledge manual adjustments like an auto focus. Do they work fine immediately? Are certain adjustments needed to be made in the camera settings? Do the bodies need to be modified with different equipment(sensor, focusing screens, etc.)?

I have:
SMC Pentax-M 1.4 50mm
SMC Pentax-M 2.8 28mm
Asahi Takumar 2.5 135mm
Vivitar 2.8-4.0 70-210mm

[Adam]

Yup they'll all work fine.

https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...k-x-k-7-a.html
The Pentax Camera Lens Compatibility Chart

[sterretje]

I doubt you will be able to fit a split prism focusing screen in a mirrorless camera

Be aware that field of view of a given lens will be different. To get the same field of view that your 28mm currently gives you on your MX, you need an 18mm on an APSc dSLR. Or with other words, your 28mm will give the same field of view as 42mm would have given you on your MX.

[dms]

I was in the same position you are in and after speaking with a Pentax rep at the NYC photo show--who suggested I buy the pentax and use my screw mount lenses w/o any newer lens--to become acclimated/use the dslr like an old film camera, I found the K20d in my case, worked just like an older slr--the minor difference was no auto aperature closure like on my spotmatic. Here I am now with about a dozen lenses--screwmount and K mount, including one m mount and one A mount, and only one newer FA which I never use in AF. They all work perfectly--in fact zone focusing with screw mount in aperture priority is not a handicap, but rather a great way for street shooting.

[dms]

(RE: your question about the screen.) I forgot to say I immediately switched to the older screen (from istd) to fix the non linear exposure problem with older lenses. With a newer camera this likely means a 3rd party screen, or some trial and error/adjustments based on lens and it's f stop. Of course you could still use a separate light meter--actually I still use a studio incident meter a lot with it (and I found I needed a +1.5 ev adjust for raw).

[taurus9]

Hard to say how the manual lenses will work with the rumored mirrorless Pentax DSLR since there's little details on what the camera will be like; specifically, what the viewfinder experience is going to be.
However, Adam's link will let you know how the current crop of DSLRs work with manual lenses.

[Lowell Goudge]

I am not sure of the value of a mirror-less K mount body, other than higher frame rates or specific for video use.

The regestry distance will dictate a substantial sized camera, about the same as a DSLR but with no view finder.

Unless they include an eye level electronic finder, focusing and viewwing will be using th elarge LCD like a P&S camera, but the way you would hold this camera to focus makes it less stable than a DSLR so you need much higher shutter speeds for image stability since you cannot hold it properly.

As for metering, unless someone reverses a trend, I would not expect metering to be any different than at present, i.e. no aperture ring coupling, to know the selected aperture of legacy lenses, therefore you would be doing stopped down metering and viewing, on what probably would be a very noise prone image.

for me, a clean optical viewfinder is the best, Even f they come out with such a camera, I would probably pass

[AntonV]

Unless they include an eye level electronic finder, focusing and viewwing will be using th elarge LCD like a P&S camera, but the way you would hold this camera to focus makes it less stable than a DSLR so you need much higher shutter speeds for image stability since you cannot hold it properly.

That's a great point. I didn't think of that. I guess a viewfinder will be a deal-breaker for me.

[Nick Siebers]

Maybe the k-01 isn't perfect for you, but as someone said above you can get a decent k20d, even a k100d for a few hundred bucks (you will easily make it up in film processing costs). Great cameras, and easy to "ease into" from film. Get a DA 18-55 to go with, for AF if/ when you want, and you are ready to roll!

[TaoMaas]

For me, the biggest loss in moving from film to digital was the inaccuracy of the metering with my old lenses. Other than that, it's mostly been a very positive experience.

[Lowell Goudge]

For me, the biggest loss in moving from film to digital was the inaccuracy of the metering with my old lenses. Other than that, it's mostly been a very positive experience.

that is somewhat lens dependant, and could have been corrected for in K mounts (but not M42) with an aperture ring coupling. BUT since pentax has not made a lens since about 1983 that required this coupling for other than origonal K & M body compatibility it ultimately got deleted.

It was a dissapointment to discover it got deleted beecause if we had that coupling, the P-TTL flash could work with K mount lenses, as it would know how far the lens would stop down for exposure relative to the open aperture preflash metering.

also note that the K5 metering has returned to about the same accuracy as the *istD, and is pretty good with manual lenses again. K10D and K20D were the worst (IMO)

[lytrytyr]

like a P&S camera, but the way you would hold this camera to focus makes it less stable than a DSLR so you need much higher shutter speeds for image stability since you cannot hold it properly.

If the LCD is articulated,
you could use the camera like any reflex
(single- or twin-lens)
with a waist-level finder,
and regain the stability.
I used to use a Canon A640 P&S like this.
It didn't have image stabilization,
but shake wasn't an issue until really low shutter speeds.

[MSL]

Yup they'll all work fine. How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-5, K-r, K-x, K-7...) The Pentax Camera Lens Compatibility Chart

Adam,
If you go to this chart, is has a lens type AF (second column from the right) which is not explained on the page of explanations. Can you shed any light on this?
thanks

[boriscleto]

Adam,
If you go to this chart, is has a lens type AF (second column from the right) which is not explained on the page of explanations. Can you shed any light on this?
thanks

That would be the SMC Pentax-AF 35-70/2.8 in KF mount. It was the only lens made for the ME F, the first auto-focus camera made by Pentax in 1981.

SMC Pentax-AF 35-70mm F2.8 Reviews - Non-SMC Pentax Zoom Lenses - Pentax Lens Reviews & Lens Database

Pentax ME F - Autofocus Film SLRs - Pentax Camera Database and Reviews - DSLR, Digital, and Legacy Cameras

[philbaum]

The K01 offers this "peaking" focusing aid for manual lenses that is a new experience to any Pentax only members. There have been no reports yet on how easy this is to use with manual lenses. I think Fuji and Sony, perhaps others also offer it with mirrorless.
For that reason, i would hesitate to buy a conventional dslr until we find out if this peaking option works well in the K01.

You can go to split focusing screens to the dslrs, but after you put it in, you will find that the "spot metering" mode no longer works correctly. So you have to choose between split focusing screen (and no spot metering) and the default setup. I''ve had the Katzeye screen in the K10 and moved it to the K20. But in K5, i didn't buy one bacause i found out how useful spot metering can be.

YMMV.