[scotforthlad]

My only digital photography experience has been with a Canon 4MP point and shoot.However I am looking into moving on to a DSLR and I believe that my Pentax M,K mount manual lenses can be used with some of the Pentax DSLR models.I would be very grateful if someone could confirm this,and identify the Pentax models concerned,so that I can investigate further.

Thanks,and Good Morning from Wales.

Brian.

[Erik]

Any Pentax K-mount lens will function on any Pentax digital SLR.

[Stefan Carey]

Some of the older lenses (manual lenses for instance) will still work, but there might be a little more work involved than a lens that will focus automatically. Even so, as Erik said, they will all work. It's a great way to recycle, and the quality of some of the older lenses can be stunning, and they are not expensive. I have just bought two older lenses.

Here's a photo from an old Rikenon macro zoom (manual):

http://farm4.static.flickr.com/3573/3373489375_eb2ea040a3_b.jpg

And here's one taken with a Pentax 35-70mm bought on eBay last week or so. Today I was trying the lens out for the first time:

http://farm4.static.flickr.com/3588/3443779947_4f7f05117c_b.jpg

[pschlute]

Your Pentax M + "K" lenses will work with the *ist- range and the K range of digital cameras.

They will not auto focus, you have to do that manually, but you will be able to use the Autofocus confirmation on the camera.

You should use them in Manual exposure mode. There are two methods:

1. You use the DOF preview button to bring up the exposure bar and adjust the shutter speed or aperture on the lens to get correct metering.

2. Set the aperture on the lens and then press the "green" button, which stops the lens down and takes a meter reading and sets a shutter speed for you.

You can use the lens in Av (aperture priority), but this only takes pictures with the lens wide open.

There are exposure/metering errors with the K10 and K20 at least (possibly other cameras). I wont go into detail but these errors can be fixed by replacing the focus screen with one that is compatible with stop-down metering.

[Quension]

1. You use the DOF preview button to bring up the exposure bar and adjust the shutter speed or aperture on the lens to get correct metering.

Note that the newest K-m does not have this optical DoF preview function, but the other models do.

2. Set the aperture on the lens and then press the "green" button, which stops the lens down and takes a meter reading and sets a shutter speed for you.

Some models don't have an actual Green button, but they all have this functionality using some button.

[nanok]

i think it should be clear by now: unlike.. well, everybody else on the market, just chose a pentax digital body that suiths you, your lenses will all work (at least to some extent). unfortunately, this means that you really have to do your research on all the models you find available and chose (with nikon for instance it would be much easier: d200/d300 and up, and as d2/d3 and the like are bloody expensive, you would probably stop at dx00, or forget about it altogether ).

[Marc Sabatella]

Also, if you aren't familiar with the so-called "crop factor" and how it affects the field of view of your lenses, you should look into that (I'm sure Google will turn up more than ever could have asked for). The lenses will work, yes, but they will work *differently*. 35 is the new 50, 135 the new 200, etc.

"Any Pentax K-mount lens will function on any Pentax digital SLR."
This is a totally true statement I can not argue with, but anyone that tells you that "Any Pentax K-mount lens functions well on any Pentax digital SLR" is dead wrong.

[Canada_Rockies]

"Any Pentax K-mount lens will function on any Pentax digital SLR."
This is a totally true statement I can not argue with, but anyone that tells you that "Any Pentax K-mount lens functions well on any Pentax digital SLR" is dead wrong.

They function very nicely, thank you. They may not auto expose, but you can meter with the camera. You can leave the AF.S switch on and wait for the subject to go through the focus point (Snap-in-focus with any manual focus lens on any AF SLR from Pentax, Catch-in-Focus with AF lenses on k20D).

[Mike Cash]

"Any Pentax K-mount lens will function on any Pentax digital SLR."
This is a totally true statement I can not argue with, but anyone that tells you that "Any Pentax K-mount lens functions well on any Pentax digital SLR" is dead wrong.

Please elaborate.

[tybeck]

Whether manual lens "function well" on newer Pentax digital bodies is a matter of opinion. Don't expect to be able to press a button and just take a wonderful picture. As said you can expect the same level of functionality that you'd find on an old film with through the lens metering and no auto focus.

[pschlute]

I have to disagree with Jeff also. I find my M and "K" lenses perform not just well, but excellently on my K10.

I expose the same way as I did with my first film camera, by adjusting the shutter and aperture until I get a centre reading on the exposure meter. It is not hard.

The exposure errors on some models (K10 + K20 for sure) can be completely rectified by fitting a different focus screen.

Using the histogram correctly when you take your shots (as you should do even if using auto-exposure on a modern lens), will enable you to get perfect exposure even if you use the stock focus screen.

I think it is a bit much to criticise Pentax in this regard. Let us not forget we are using a modern DSLR with 30 year old lenses. Try going to Microsoft in 30 years time and tell them you have a problem with your version of XP and they should fix it.

[Lowell Goudge]

I have to disagree with Jeff also. I find my M and "K" lenses perform not just well, but excellently on my K10.

I expose the same way as I did with my first film camera, by adjusting the shutter and aperture until I get a centre reading on the exposure meter. It is not hard.

The exposure errors on some models (K10 + K20 for sure) can be completely rectified by fitting a different focus screen.

but why should we have to?

Using the histogram correctly when you take your shots (as you should do even if using auto-exposure on a modern lens), will enable you to get perfect exposure even if you use the stock focus screen.

no disagreement. once you know how your lenses work with your metering exposure issues go away and the lenses do perform very well.
The only 2 exceptions are chromeric aborations, since many older designs were not Aprochromatic lenses (focsing all colors at more than just the focus point) you will get green and purple fringing on oout of focus points, and rather long minimum focusing, since the lens designs are not internal focusing.

I think it is a bit much to criticise Pentax in this regard. Let us not forget we are using a modern DSLR with 30 year old lenses. Try going to Microsoft in 30 years time and tell them you have a problem with your version of XP and they should fix it.

Here I disagree, not because the lenses are 30 years old, and it would be unrealistic to expect support for 30 year old software (using your example), BUT because pentax aggressively advertised that there were 23 million lenses made that could be used on this series of cameras.

I found it disappointing that while they did not stress using older lenses on the *istD it meters very well with K mount lenses, and has TTL flash capability, the K10D and K20D don't meter as well, and don't support the older lenses by offerint TTL flash, yet were marketed much more as useable with older lenses while funcionality was actually taken away.

Owning an *istD (and intending to keep it because it works so well with old lenses) I believe I have a right to express disappointment on the reduced support for old lenses found on the K10D and K20D.

After all the K10D and K20D are the successors to the top of the line (at the time ) *istD

[pschlute]

Lowell

You make some valid points.

The focus screen for the K10 was meant to be brighter than the *ist range. It causes problems with metering with old lenses and Pentax should have tested it more thoroughly with the old lenses, I agree. However the solution is very simple and if you like using the oldar lenses it is a no-brainer. "Why should we"? To have a great camera work better with old lenses is the answer! Would you have refused to buy the K10 if you had known this limitation, and also known the solution was so simple?

CA and Aprochromatic design (I confess ignorance on the latter) are an issue, but can hardly be called a design fault (not that you did). Use of a hood and careful positioning in relation to stray light (and avoidance of contrasty scenes), are important as these lenses were never designed to deal with the more exacting requirements of a digital sensor. But the same can be said for many lenses on the market today.

I think the last point you make about how Pentax advertised the compatability is an interesting one, and I cannot argue that there was a reduction in functionality over exposure and TTL metering. But the latter was an issue that not only applied to old lenses, as the move to PTTL applies equally to the DA lense lineup too.

[ve2vfd]

anyone that tells you that "Any Pentax K-mount lens functions well on any Pentax digital SLR" is dead wrong.

I'm also curious to hear why you state this? Please define "functions well"...


My M50 f1.7 is probably the most pleasant to use lens I have and give awesome results. My Takumar 135 also delivers some seriously pleasant results.

As for my sigma mirror 600mm I'll admit that it's definetly NOT easy to use, but with patience and practice it does produce magical pics.

Pat