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Pentax K10d and Manual focus lenses
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PostPosted: Thu Nov 01, 2007 3:12 am    Post subject: Pentax K10d and Manual focus lenses Reply with quote

In this thread, I noticed an interesting discussion between Attila, Flor27 and PapadakosPanagiotis regarding the lack of support for MF lenses from majors brands producing DSLRs.

As stated by PapadakosPanagiotis, "at least Pentax K10D supports it"!

Yes, definitely. And that's the main reason why I bought a K10d. It's a real pleasure to be able to use my Tamron Adaptall-2 SP 180/2.5 in aperture priority automatic mode, with AF confirmation and image stabilization. As the K10d is an APS-C format camera, the lens has the same field of view as a fast f/2.5 275mm lens.

And if I need some more reach, I can always add the Pentax 1.7x AF adapter and, voil?! my lens becomes a powerful f/4.0 306mm telephoto, equivalent to a 468mm lens on full frame 35mm. I shouldn't state this on a forum dedicated to manual focus lenses, but the 1.7x AF adapter also turns MF lenses into AF lenses, albeit with a limited AF range.

Here's a picture taken wide open with the Tamron 180/2.5 at 1/160sec. with image stabilization:



Maybe you noticed the tiny ant on the bitter gourd. Here it is, at 100% size:



And now a picture taken wide open with the Tamron 180/2.5 and the Pentax 1.7x AF adapter (306mm resulting focal length) at 1/100sec. with image stabilization:



There are two drawbacks when using manual focus lenses on the K10d.
- Lenses with automatic diaphragm actuation need to have an "A" setting on the diaphragm ring in order for the camera to be able to meter in automatic mode with aperture priority (Av). It means that old Pentax K and Pentax M bayonet lenses will only allow the use of "M" mode on the K10d, with manual metering at the push of a button prior to the exposure. This is not a problem for Tamron Adaptall lenses, because they have an "AE" setting on their diaphragm ring. M42 lenses can also be used in "Av" mode, but only with stopped down metering when the lens is switched to the "Manual diaphragm" setting.
- The exposure metering on the K10d is very accurate with KAF lenses. With manual focus lenses, it's OK but only when the lens is used wide open. When the lens is stopped down, the exposure tends towards overexposure and needs to be compensated. The more one lens is stopped down, the more compensation is needed, sometimes exceeding the -2EV range of the camera.

Even with these shortcomings, I find the K10d a very nice complement to my Canon EOS 1Ds. I use the Canon mostly for landscape and cityscape work with wide angles and in the studio with moderate telephotos, while I prefer the Pentax for family events, wildlife shooting and travel photography. I am very glad than these two cameras can share a wide range of lenses. In fact almost all my lenses (MF, of course) can be used on both cameras.

Cheers!

Abbazz


PostPosted: Thu Nov 01, 2007 9:15 am    Post subject: Reply with quote

The Pentax Corporation will be disbanded on March 31, 2008
This will finally mark a full stop to the 88-year old Asahi / Pentax company which was first established in the November of the Year 1919.

http://ricehigh.blogspot.com/2007/10/hoya-is-to-dismiss-pentax-by-this.html


PostPosted: Thu Nov 01, 2007 10:10 am    Post subject: Reply with quote

poilu wrote:
The Pentax Corporation will be disbanded on March 31, 2008
This will finally mark a full stop to the 88-year old Asahi / Pentax company which was first established in the November of the Year 1919.


Sad news, but I guess it won't affect much the Pentax users. I will still enjoy shooting my Asahiflex with its cute 58/2.4 Takumar lens (a great 5 element lens, one of the only copies of Voigtlnder's original Heliar lens ever designed for 35mm). New cameras will still be produced by the same team that used to work for Pentax and sold under the Pentax brand. Anyway, I leave the discussion about the future of Pentax cameras to the fanatics on DPReview forums...

Cheers!

Abbazz


PostPosted: Thu Nov 01, 2007 10:25 am    Post subject: Reply with quote

niblue wrote:
The *istDS (and similar) generation of Pentax DSLR's is actually better than the K10D with pre-KA lenses for a couple of reasons...


Sure, I have a Pentax *istD which has its advantages, but the discussion on this thread was about other brands not offering AF confirmation and image stabilization with older lenses.

Cheers!

Abbazz


PostPosted: Thu Nov 01, 2007 10:53 am    Post subject: Reply with quote

what I don't understand is how the k10d know the focal length of the adaptall-2. In the first shot the exif report 180mm and with 1.7x it report 300mm. That's nice, with the canon I have to modify exif myself.
Does it work also with zoom; does it work with other mount than adaptall-2.
btw 300mm at 1/100 is really impressive


PostPosted: Thu Nov 01, 2007 11:10 am    Post subject: Reply with quote

Abbazz wrote:

Sad news, but I guess it won't affect much the Pentax users.


Well, I hope so, too, but cameras get old, and without the proper replacement parts, digital cameras are trash, because they can not be repaired, differently from old mechanical cameras, which often can be repaired using generic parts in stead of specific ones.


PostPosted: Thu Nov 01, 2007 11:12 am    Post subject: Reply with quote

Quote:
KA version of the Adaptall 2 mount

must be that
Click here to see on Ebay

Quote:
Because it has electronic contacts it can be used on the A auto setting on newer Pentax bodies


but the adaptall lenses have no electronics. How they transmit the focal length to the adapter.


PostPosted: Thu Nov 01, 2007 3:06 pm    Post subject: Reply with quote

Quote:


but the adaptall lenses have no electronics. How they transmit the focal length to the adapter.


I think it's becaue for the SR in the K10D to work, you have to input the focal length yourself with manual lenses Smile

Tom


PostPosted: Thu Nov 01, 2007 3:09 pm    Post subject: Reply with quote

poilu wrote:
The Pentax Corporation will be disbanded on March 31, 2008
This will finally mark a full stop to the 88-year old Asahi / Pentax company which was first established in the November of the Year 1919.

http://ricehigh.blogspot.com/2007/10/hoya-is-to-dismiss-pentax-by-this.html



statement by USA Pentax president Ned Bunnell: http://nedbunnell.blogspot.com/2007/10/pentax-usa-letter-to-customers.html

Pentax won't cease to exist, it's simply becoming a division of Hoya.

You had me worried there for a sec Wink

Tom


PostPosted: Fri Nov 02, 2007 4:39 am    Post subject: Reply with quote

TDN wrote:
I think it's becaue for the SR in the K10D to work, you have to input the focal length yourself with manual lenses Smile


You're right, Tom. That's another nice feature of the K10d when used with old manual focus lenses. When you switch on the camera and it has an MF lens mounted, then the camera prompts you to select the focal length of the lens in order to optimize the image stabilization for the lens being used. As a consequence, the focal length of the lens appears in the EXIF data and can be retrieved easily. I find it rather handy to be able to determine which lens was used to take a given picture by looking at the EXIF data, even for old lenses.

For zooms, you have to select a mid-range value but I don't use MF zooms much. Of course, with modern Pentax lenses, the correct focal length is transmitted automatically via the electric contacts on the lens mount and doesn't need to be selected by the user.

Cheers!

Abbazz


PostPosted: Sat Nov 03, 2007 12:26 am    Post subject: Reply with quote

You mean you can mount M42 lenses AND use IS with them! why am I wasting my time with canon!


PostPosted: Sat Nov 03, 2007 12:32 am    Post subject: Reply with quote

hacksawbob wrote:
You mean you can mount M42 lenses AND use IS with them! why am I wasting my time with canon!


Careful, with Pentax camera, you will have to say goodbye to Contax/Yashica mount lenses.

-


PostPosted: Sat Nov 03, 2007 12:36 am    Post subject: Reply with quote

And lot others, like Nikon etc , M42 ass of pain...

I suppose we have only two good choice Olympus and Canon.


PostPosted: Sat Nov 03, 2007 2:22 am    Post subject: Reply with quote

Attila wrote:
And lot others, like Nikon etc , M42 ass of pain...


Old Nikon lenses (non AI) mount directly on Pentax DSLRs (no adapter required) and all M42 lenses can be used in full automatic Av mode, with image stabilization and AF assist. No such things with my Canon Sad

Cheers!

Abbazz


PostPosted: Sat Nov 03, 2007 9:12 am    Post subject: Reply with quote

No CY, is that because of registration distance? or no mount been made yet?

Atilla what is the "ass of pain" Laughing in changing mounts?


PostPosted: Sat Nov 03, 2007 9:50 am    Post subject: Reply with quote

hacksawbob wrote:
No CY, is that because of registration distance? or no mount been made yet?


No C/Y because of register distance.
And for the same reason, no Olympus Zuiko lenses, and no Zeiss Rollei lenses.

-


PostPosted: Sat Nov 03, 2007 9:54 am    Post subject: Reply with quote

Rolling Eyes for manual focus lenses it would have been ideal!


PostPosted: Sat Nov 03, 2007 10:02 am    Post subject: Reply with quote

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00JV3z


PostPosted: Sat Nov 03, 2007 12:55 pm    Post subject: Reply with quote

niblue wrote:


Apparently the Pentax mount can be modified to take C/Y lenses and still work with K mount:

http://forum.contax-club.org/viewtopic.php?t=12815

C/Y lenses can also be adapted to M42 mount:

http://forum.contax-club.org/viewtopic.php?t=12815

And finally C/Y lenses can be modified to take a K mount:

http://forum.manualfocus.org/viewtopic.php?id=7869


All these methods are painful to the lenses or the camera, and not all lenses are modifyable this way according to your links. Adaptation of the lenses require adjustment to the register distance and doing this home-made is a big risk of trashing your investment. Would you risk such a modification on a 600-1000 or even more Euros lens? Especially when with 600 Euros you can buy a new 400D body and keep your Contax lenses pristine, protecting your investment. Contax lenses aren't 20-euros lenses that you can dispose of with a light heart.

For the above reasons, the whole modification thing on Contax lenses does not make sense to me: if you want to use Contax lenses digitally, buy a 400D for 600 Euros, and use them intact. For the other lenses, you can use a Pentax reflex body if you prefer it. This is, by far, the most sensible choice, both ergonomically and financially.


PostPosted: Sat Nov 03, 2007 1:11 pm    Post subject: Reply with quote

Pentax and M42 has same register distance , imagine how difficult to build and use an adapter. M42 can be problem on Canon too if adapter thick, cannot support infinity. On Olympus my M42 adapter is 5mm thick so easy to make it and use it.


PostPosted: Sat Nov 03, 2007 1:12 pm    Post subject: Reply with quote

From current available cameras if I have to choice one I vote for Canon 400D.


PostPosted: Sat Nov 03, 2007 2:20 pm    Post subject: Reply with quote

Attila wrote:
Pentax and M42 has same register distance , imagine how difficult to build and use an adapter. M42 can be problem on Canon too if adapter thick, cannot support infinity. On Olympus my M42 adapter is 5mm thick so easy to make it and use it.


Actually Attila, there's been one ever since the K-mount was made Smile



It just locks inside the mount and you can screw on M42 lenses. I use it on my *ist DL all the time.


Very interesting stuff about mounting C/Y and Nikon lenses on pentax DSLRs! I will see what I can try without damaging my camera.

Tom


PostPosted: Sat Nov 03, 2007 2:39 pm    Post subject: Reply with quote

TDN wrote:

Very interesting stuff about mounting C/Y and Nikon lenses on pentax DSLRs! I will see what I can try without damaging my camera.
Tom


I would be more careful in not damaging the lenses if they are worth more than 100 Euros. You can always have the camera repaired by any Pentax service, while once the lens is screwed up by improper surgery, it is trash, and old manual lenses are not easily replaced because they are not in production anymore.

Also it is my opinion that we should respect these old lenses and modify them only if absolutely necessary.
-


PostPosted: Sat Nov 03, 2007 2:56 pm    Post subject: Reply with quote

Quote:
we should respect these old lenses and modify them only if absolutely necessary.


And try and make any mods reversible.


PostPosted: Sun Nov 04, 2007 1:33 am    Post subject: Reply with quote

Attila wrote:
Pentax and M42 has same register distance , imagine how difficult to build and use an adapter.


Attila, I guess you are confusing with Nikon cameras. Because of the registration distance, M42 lenses cannot be used on Nikon cameras, except when using special adaptation rings with a built-in optical element (but the additional lens adds some aberrations).

On the other hand, the Pentax K bayonet was created especially to allow easy mounting of M42 lenses. The registration distance of the two mounts is the same (45.46mm) but the Pentax K has a slightly larger diameter, allowing for the adapter ring to slip in between the lens and the camera mount. Right from the beginning, an M42/PK lens adapter has been made available by Pentax. I remember using one in the late 1970s with my first SLR, a Pentax MX.

As mentioned at the beginning of this thread, the Pentax K10d not only allows me to mount M42 lenses easily, but it also allows me to use image stabilization and AF focus confirmation right out of the box (no need for these "chipped" adapters like on my Canon).

Except for wide angles, I always switch to my K10d when I plan to use M42 or Tamron Adaptall lenses, because it is much more usable than a Canon with these lenses. On the Pentax, all the Tamron Adaptall lenses perform exactly like native Pentax KA lenses, with the all the auto-exposure modes available and the control of the aperture on the camera body. And with the help of the 1.7x AF adapter, my Tamron Adaptall 300/2.8 and 180/2.5 turn magically into multimegabucks superfast autofocus lenses...

Cheers!

Abbazz