Mirror lens, adaptall mount, DSLR

[300bhp/ton]

I've got an old Tamron 500mm/F8 mirror lens that I used to use with my 35mm camera's. Haven't used it in years, it uses the 'adaptall' mount. I have a P/K mount as I used to use it with Pentax film camera's. I then moved to a Nikon DSLR, but I'm back with Pentax now with the K-50 DSLR.

I can't seem to get the lens to work on the K-50, it just flashes up F on the screen and won't release the shutter. (using manual).

It seems it can't resolve the F8 aperture of the lens. My hunch is, the apatall ring I've got isn't a P/KA and is causing this problem. Although hoping there might be a camera setting to get around this.

Photobucket is down (again....), so can't post a picture of the lens and adaptall at the moment. But any insight anyone might have would be useful thanks.

[Simpo Two]

I'm not a Pentax expert but the camera is probably looking for contacts the lens doesn't have and saying 'I can't work this'. Some DSLRs can be set to work with 'dumb' lenses but I don't know if the K-50 will.

[droopsnoot]

I don't know about the K50 either, but I've got a Kx and bought a Tamron SP 500mm F8 mirror lens and had no trouble with it. Obviously had to switch the camera to manual focus (I think, or maybe it just did that). I haven't used it for a bit, as I bought a Sigma 50-500 and feel the need to get the value out of it. There was some talk about covering the contacts on the camera mount with tape to stop things getting upset, but I forget what model (or even make) that referred to. The mount on mine just says "For Pentax K.M."

I'm sure you've searched, but I also found this: http://support.us.ricoh-imaging.com/node/1536

and this : http://www.pentaxforums.com/forums/58-troubleshoot...

Edited by droopsnoot on Friday 4th November 11:40

[checkmate91]

I have a tamron 500 with an OM mount. I also have a tamron to EF adaptor and OM to EF adaptor (I like my old Zuiko primes). One of the adaptors has a chip which gives me a focussing bleep but does nothing for exposure, that's manual guesswork I'm afraid.

I have to say though that on my 7D the results are disappointing, the lens gives a soft, almost cloudy resolution. It's clean, no dust and the mirror seems flawless but I dont use it. Also, the focus ring has an almost impossibly narrow sweet spot, that doesn't help either. As a spotting scope it's ok (esp with the 2x converter that came with it) but for pics? No.

Edited by checkmate91 on Saturday 5th November 08:59

[Top Banana]

With most modern pentax DSLR's you have a setting in the menu which will enable use of older manual focus / aperture lenses.

If this has not been set then the camera will flash f-00 in the display as it cannot recognise lens

Once you have enabled this setting then you can use the manual setting or the green button to meter the exposure value. Also the camera will ask for the lens length as it can set the in-body stabelisation for the lens being used.

Have a look over on pentax forum as there will be loads of guides to using manual lenses with various pentax bodies

Regards - Tb (pentax k3 and k5 user)

[300bhp/ton]

Thanks for the link @droopsnoot and the info Top Banna. That seems to have done the trick, Thought there must be some way of getting it working. Not sure how good the pics will be, will need to have a go with it now and see.

[Top Banana]

good to hear you have got it working - mirror lenses can be tricky beasts, mine is an old soviet MTO-3M5A 500mm with fixed f8 aperture and these are a few of the images I have got from it (both are handheld shots but it works best on a tripod)

blue moon by jon bawden, on Flickr

donut bokeh from mirror lens by jon bawden, on Flickr

you can see in the second shot the distinctive 'donut' bokeh that you can get with the mirror - this can be a real pain but also you can use it as part of the feature of the shot...

good luck, and post up some pictures once you have got some