Lens compatability between Digital slr and old Pentax film slr

I currently own aPentax ZX-50 SLR and have had it for over 10 years. As part
of the kit it came with the Pentax-F 35-80mm lens and I also purchased a
Tamron AF 100-300mm lens. I am now considering stepping up to a digital SLR
and I am considering the Pentax K10D and I am wondering if these lens will
work with the new digital camera. Also will the auto focus feature of the
K10D work with these lens also, I understand that the Pentax has the
autofocus built into the camera and not the lens.

Thanks.

 

Yes, both of those lenses will work just fine with the K10D! However, you
will have to put the aperture setting on "A" and control the aperture from
the camera, rather than the lens.

For the gritty details of lens compatibility, search for Bojidar Dmitrov's
extensive page... however, to make a long story short, all the Pentax
lenses all compatible with the new DSLRs except that you can't use the
aperture ring.

*All* Pentax SLRs (both film and digital) have in-camera focus motors,
except for one short-lived early 80s model. So autofocus will work just
fine.

I personally use a couple of old lenses (A50 f/1.7, and A70-200 f/4) with
my new K10D and they both work great. Metering is perfect, and the shake
reduction works too because it is in-body The extensive compatibility
with old, inexpensive lenses is one of the main reasons I chose Pentax.

Dan

 

Pentax is expected to announce a replacement for the K10D at the PMA
show in Las Vegas, which starts on January 30, 2008. It would be
worth waiting to see what new DSLRs are announced at PMA before you
make any major buying decisions.

DPReview normally offers up-to-date reports on announcements at PMA,
so watch this space:

http://www.dpreview.com/

 

The autofocus is in the usual place, but in its current cameras Pentax has
"Shake Reduction" built into the body rather than the lens, which means that
you can still benefit from SR using your existing lenses. Other brands have
SR in the lens, so old lenses won't give SR.

As for the rest, yes your lenses will work
Daniel mentioned that you'll have to set the aperture ring to 'A', this is
the default setting, but AFAIK it's not essential for the K10D; AIUI you can
change a setting so that you can operate in full Manual mode. There is a
button you can press that sets the appropriate shutter speed .

I've got the K100D rather than the K10D, both are very nice cameras, and
should be real bargains as the K20D and K200D are introduced.

Don't forget that the sensor is smaller in the DSLR than in a film camera,
so your old lenses give the same field of view as a 50% longer focal length,
A 35mm behaves like a 50mm, and your 100-300mm will be the equivalent of a
150-450mm telezoom. This sounds good, but it means it will be worth looking
for a new wide angle lens.

 

Well, the specs on the K20D (its presumed name) are all-but-revealed
already, since the Samsung GX-20 has been leaked: http://
www.engadget.com/2008/01/10/samsungs-gx-20-dslr-leaked/ Just as the
Samsung GX-10 is a clone of the Pentax K10D, the GX-20 is probably a clone
of the K20D (the two companies collaborate in their design).

More interesting to me is the likely K200D... it's rumored to have a
similar body to the K100D Super, but upgrading some features to the K10D
level: 10 megapixel, 3 fps unlimited JPEG shooting, better autofocus.
Could be an amazing deal if it keeps the K100D's entry-level price point
of under $500 for the kit.

On the other hand, Pentax K10D and K100D Super prices seem to have swung
markedly upward in the month since I got mine... apparently there's a
supply shortage right now since they've reduced production of the K10D and
K100D. Prices may actually go up if there's a long wait until the new
models actually hit the shelves.

Of course, all this is speculation, I guess we'll find out in 10 days

Dan

 

That's a good point, which I'd forgotten. You *can* use the aperture
rings on older lenses, but then you have to do stop-down metering, which
is a little slower, unless you're in full manual mode. I've used it
though, and it works as expected!

Dan

 

Lee-

Isn't the ZX-50 an autofocus SLR? If so, and those lenses are
autofocus, they should work perfectly with any of the Pentax DSLRs.

If you have older manual-focus KA lenses, set the aperture ring to the A
setting. Other than having to manually focus them, they will work
perfectly otherwise.

The old K (Non-A) series lenses will work, but it is a little more of a
bother to use them, as will old screw-mount lenses with an adapter.

Fred

 

Daniel Lenski wrote:

It's what I do with my old screw mount lenses. The adapter ring lets all
the 42mm stuff to bolt onto the K type mount. I love the backwards
compatibility of Pentax bodies.





mike

 

Not with "A" lenses.

Just set the aperture ring to A and you get everything except
autofocus.

 

Price difference between the new one and the k10 is likely to be $600-
$800. The K10D is probably (next to the $1000 D200 bodies out there
now) the best value in a DSLR. Too bad about Pentax's poor telephoto
(near non-existent) offerings.

 

Mostly shooters don't actually buy big glass anyway so it is rarely a
problem, thos few that do need the big guns shoot Nikon or Canon anyway but
pay a huge price for the privilage.

 

I'd probably put that as 'not' using the aperture ring

 

OK, agreed.

;-)

 

I think Olympus and Pentax miss th boat by no longer/not having 300mm
f4 lenses for about $1000.00.

 

Well... there are Sigma options for the Pentax cameras. And Tamron is
coming out with some more lenses, and Pentax is also supposed to come
out with their own 300mm prime at some point soon.

Dan

 

This is the situation I had, except I had the Pentax ZX-5n, hence
I bought the K10D, and I love it. The lenses are 100% compatible.
Keep in mind the 1.5x factor between film and DSLRs.