Aperture control of manual lenses on K10D

I have a strange desire to try some old M42 lenses on my K10D, the less mainstream stuff seems to be pretty cheap in charity shops and the like

but I read on Steve Gandys Cameraquest website that most M42 lenses (other than Takumars) have a sprung aperture that stays open, so does this mean if I have an f2.8 lens and set it to f5.6 the aperture springs back ?

My only comparison is my Adaptall 1 CT135 has an M switch and works great, my Adaptall 2 103A does not. The CT135 works ok in Av setting but the 103A has to be used with the green button in M

Sorry if this seems a complete newb question but I am unfamiliar with the more arcane forms of photo kit

info source here:
http://www.cameraquest.com/adaptslr.htm

sort of lens I like the look of here:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=150421879415&ssPageName=STR...

Some (most/all?) Takumars have a sliding Auto/Manual switch. If you switch it to manual it disables the spring mechanism and lets you just set the aperture with the aperture ring.

thanks Tim, that it pretty much what I have found with my Tamrons (and why I prefer the earlier ones)

but what about non Pentax M42 lenses, suppose I buy a Schneider Krueznach without a switch - can I only shoot wide open ?

I'm just a dabbler (where's Hefty when you need him? ) but I think if it's an M42 lens which doesn't have a manual mode, your only options are to perform a little surgery, or to glue the pin so it's always in, or to get one of those M42-PK adapters which have a flange which depresses the pin on the lens mount.

Update, these are the adapters I'm talking about, not the ones with the flange on the top (lens side) which make you lose infinity focus.

Tim

exactly the info I need, and more - thank you

sounds like I can go after the glass I like the look of and deal with the consequences one way or another (so long as I avoid Ricohs with pins)

joined the Mflenses forum too, more to explore

thanks again

No problemo! Mflenses is quite interesting if you like old glass. Some of those guys are rabid

They are quite an eccentric bunch but fun to see people being enthusiastic!

K.

Delayed by a trip to Luton Airport - but I'd have said much the same as you anyway.

Most M42 lenses have the Auto/Manual switch, some older Taks and Russian lenses (Jupiter-9, etc) are pre-set or manual only (fine to use) and it's actually quite unusual to come across a lens that's Auto only - the only ones that spring to mind are the later versions of the Helios-44, and they're a doddle to convert.

I wouldn't bother with the flanged adapter as you're pretty unlikely to ever actually need it tbh.

Do any other M42 lenses have the aperture coupling as used on the SMC Takumars? Still hunting a cheap lens for my ES II, the light meter isn't terribly reliable in stop down mode so it really needs a lens with that coupling.

Not that I've ever come across. The Mamiya/Sekor SX series lenses have *an* aperture coupling but it's in a different place to the Pentax one so not compatible. The only other variation I'm aware of are the "electric" lenses for Praktica cameras (CZJ and Pentacon) which have electrical contacts (hence the name) on the lens mount, again no use on your ES II though.

Nearly all third-party lenses (Sigma, Vivitar, Soligor, Hanimex, etc) used a vanilla M42 mount with an A/M switch in order to broaden their appeal across as many manufacturers' systems as possible.

So if you want to keep the open aperture metering with you ES II I'm afraid you're going to have to stick with SMC Taks. Although if it's any consolation then M42 lenses rarely get much better anyway.

Ah ok - I'll keep an eye out for a cheap one then. From experience most ebay buyers run a mile from lenses with fungus, it doesn't bother me so long as they're fairly simple to strip down and clean.

I nearly bought one of the 75-150mm zooms but as it was a Super Tak rather than an SMC Tak I didn't bother. Nice glassware but I already have the K series 85-210mm f4.5 which fills the role of "ancient monster lens" superbly, as well as being a lot easier to use on digital than you might expect!

I'm selling three SMC Taks on eBay right now (along with some Super-Taks) including a near-mint 200/4 which does indeed have a tiny spot of fungus on the front element. You may find that puts enough folk off to make it a bargain..?