Pentax K10D lens compatability

I have the very reliable Z1 body with SMC AF Pentax lenses: 17-28; 28-200; 80-320 and a 135mm 2.8.
My question is as I am about to go digital I have been concerned to read comments that using existing non digital lenses with a digital body produces sub standard images ie. soft, restrictions in auto focus, exposure metering..
I checked out the 'Pentax Canada' lens compatibilty chart
http://www.pentax.ca/digital/digital_slr/da_lenses/compatibility.php
to find that these lenses come under the category 3 which says 'Limited functionality' but does not explain in detail what functions I would be forsaking, I have emailed them and UK office too but after a week they still have not replied to me
Has anyone had any experience of this yet, I would like to be sure my lenses will be spot on with a K10D and would hate to be disappointed and dont relish the cost of starting all over, HELP please?

All the lenses you list are fully compatible with the Digital SLR range, no problems whatsoever.

They sound like FA lenses - PKAF2 mount but maybe the limited functionality refers to the fact that new lenses with in-built motors will soon be coming and these utilise the connector that was formerly for the powerzoom functions on the old Z cameras.....so if you have DA* then you should have full functionality on K10D, but with other lenses "limited functionality'....

Just a guess

I assume you mean the SMC-F 17-28mm fisheye, the SMC-FA 28-200mm, the SMC-FA 80-320 - all these lenses are perfectly ok on digital.
You will get all functions: autofocus, auto-aperture etc.

I use SMC-F and SMC-FA lenses that were designed for film and can say they are absolutely sublime on digital - e.g. the SMC-F 50mm/f1.4 is one of the best lenses I've ever seen, anywhere.

I think some of the issues you mention occur with other makes of lenses, like Sigma, Tokina etc. Sigma is perhaps the worst since they reverse engineer the body-lens protocol. Part of that protocol is the lens ID code which indicates the particular model - and the third party lenses often get misrepresented as different Pentax lenses. The *ist-D was built to focus on the hyperfocal distance automatically, and I suspect some of the issues are down to that. Additionally, if the light is not collimated correctly it can often work well on film, but digital is a little less forgiving (because it has the bayer filter in front of the CCD).

That said, I think you will be very pleasantly surprised at the quality you can achieve with Pentax own lenses and their DSLRs - especially the K10D

You didn't say which 135/f2.8 you have - if you have the "A" or "M" versions then there are some "limitations". The M lenses don't do evaluative metering, only centre-weighted and spot. Both types require stop-down metering too since the DSLR bodies lack the mechanical "finger" that senses where the aperture is set to. However, if you've been using the thumb/finger wheels of the Z1 then the likelihood is that all the lenses will be just perfect

Hope that helps!
Matt

sorry to have to correct you Matt, but A series lenses don't require stop down metering, only M series and earlier. Stick an A series lens in the A position and its only limitations are no autofocus and you have to set the focal length manually on the K10D and K100D

otherwise bang on the money as always.

Correction accepted Yes - "A" series lenses work a dream.

Serves me right for typing too much
Matt

Quite right
I've been using A series lenses on ist DS and now on the K10D for ages with no problems.
Only issue is the focal length is multiplied by 1.5 hence my 200-400 is now a 300-600 (great as I use it for wildlife).

Problem is a 18mm fisheye becomes a 27mm so you may as well leave the standard 18-55 on the camera.

When using an ancient set of bellows (no electronics or cable links on it what so ever) I just set up the custom setting to permit aperture ring and it works fine (seems to be manual mode only)

I have a Z1 with the FA 28-105 zoom lens and have just pruchased the K10D. I can assure you that this particular lens works fine on the K10, even the motorised zoom of the lens functions fine. You can zoom from one extreme to the other at the 'bat of an eyelid' if required. I have not tried zooming whilst shooting with a slow shutter speed yet. That should be interesting on the K10.

But an 18mm fisheye will still give far wider angle of view than the 18-55mm kit lens
Matt

I tried that last week with the 18-55 (no power zoom). It works pretty well, the SR still seems to have some effect though it does seem to get a bit confused when the focal length changes drastically during the exposure.

Thanks Matt
You've just saved me more expense
I never tried it because I was told my old 17mm would become about 25mm on a digital camera!

What does it become?

Rodger,
Hmmm. That's an interesting question in fisheye terms...

What actually happens is that you get a centre crop. Nothing happens to the actual focal length. When you use a rectilinear lens the crop reduces the angle of view so the lens has the same AoV for a lens 1.5x on a 35mm camera.

But that can't be applied to fisheye

I can dig out the equations and work it out... but I think the best thing is just to try it

The very nice fisheye alternative for digital is the SMC-DA 10-17mm

Matt

Thanks Matt
Your quite right I've tried it and it works
Lens is so old its non AF and no A function so I'll look at the SMC-DA 10-17 as it's probably time to upgrade anyway.

Don't worry about the maths - it works which is all I need to worry about as I'm not using flash with it.

Thanks, sorry meant to type FA so they will be OK then, not worried about the power zoom bit anyway, never used it!

Matt: Thanks very much, all looks very promising, my 135mm 2.8 is also a SMC Pentax-FA (with IF under whatever that means) its fully auto-focus so presume it will be well OK with the K10D, it really is a crackin lens and was well worth the £450 my hubby spent on it!!