As the title says, £265.00 including adequately insured postage to a UK address.

Specifications can be seen here.

Boj's estimate of availability as "Used, several times a month" is not quite accurate. Try and find one, they're like rocking horse manure!

Built-in hood, internal focus, original clip-on front cap, original hard plastic rear cap.
Glass is clean and free of any marks, dust, fungus etc.
Aperture ring is snappy, focus is smooth, diaphragm is oil free.
There is slight evidence of normal use on the outside.
Filter thread is pristine and undamaged.
The lens is in very good condition.
The box is in good shape and contains only the pre-formed polystyrene liners to support the lens, no paperwork is included.

135mm telephoto lenses don't come much better than this. This is an excellent portrait lens on FF film or digital (if Pentax ever makes one).

Payment by bank transfer, cheque (UK bank), or Paypal as a gift - buyer pays fees.

The hood is a normal round hood, not petal shaped, manufactured from black plastic. Shiny outside, matt inside, It comes in a little case and is of 70's/80's vintage at a guess.

Marked around the edge of the hood; "Standard Lens 1:1.4 50mm 1:1.8-2 55mm". On the opposite side is marked "Asahi Opt. Co. Japan" & "49Ø" (49 theta - which indicates 49mm)

I used it on a SMCP-A 1:1.7 50mm and a SMCP-F 1:1.7 50mm lens. I think it was originally made for the SMCP 1:1.8 55mm or even the Takumar M42 lens of the same size.

Both hood and case are in very good condition. You are welcome to come and have a look, I'm in High Wycombe for the next couple of weeks.

IMHO, none of the available 500mm mirror lenses are brilliant. The best is probably the Tamron 500mm SP BBAR.

OOF bokeh looks odd, a doughnut shape, which I personally don't like. They are also fixed aperture, usually f8.

Without proper use/storage, the mirrors can be destroyed by fungus as well. I bought a Tokina 350mm mirror lens a few years ago and could barely see anything through it for fungus.

Whatever you do, don't be in a hurry to splash out on a load of lenses until you know what types of subjects you prefer to shoot.

The twin lens kit is an ideal 'all-rounder' kit with the 18-55mm and 50-200mm lenses. They'll probably cover 95% or more of your needs in the short term.

Beware, Lens Buying Addiction (LBA) has no known cure and is usually a very steep and expensive learning curve.

Also, don't expect award winning results from the on-board flash. If you feel you need to progress to flash, seek advice here before buying.

Final update before going on ebay.

Prime lenses
SMCP-A 24mm 1:2.8 - £129
SMCP-K 50mm 1:1.2 - £229
SMCP-M 50mm 1:1.4 - £50
SMCP-K 500mm 1:4.5 - £559

Zoom lenses
SMCP-FA 28-200mm 1:3.8~5.6 - £65
SMCP-FA 100-300mm 1:4.5~5.6 - £50

SLR 35mm bodies
Pentax MZ-6 - £70 - now includes a SMCP-FA 28-80mm lens

Sundry bits 'n bobs
2 x Pentax K-M42 adapter incl. release tool - £10 each
Pentax screw on lens hood - £15
Tokina filter kit - £15

SOLD:-
SMCP-F 50mm 1:1.7
Pentax-F 28-80mm
Pentax Z20
Extension cord F 5P
Pentax 4P Synch Cord B[/quote]

The addition of the right tube will not affect it at all except:-

You will lose AF if the tubes do not have an AF screw coupler, and
You will of course lose infinity focus, as with any tube.

Otherwise, job done.

I can recommend Kenko tubes but you might have trouble finding them. I don't think they are made any more. They are also marked, perhaps erroneously, PK/AF, but they lack the AF coupling so its MF only.

If you find some decent tubes, ensure that they have enough contacts for modern lenses/bodies. Pentax has increased the contact count over the years. As a consequence, some older tubes with contacts may have too few.

This thread explains.

From what I have read here, it would seem that:-

1: Your tubes have no contacts, and
2: Your tubes have the mechanical coupling to stop down the aperture, and
3: Your lens has electrical contacts

If that is correct, you should be able to use your lens/tube combination as if they were a Pentax M series lens or earlier. This should allow the lens/body to use the auto diaphragm capability of manual lenses. That is, the body can control the aperture of the lens by a mechanical linkage.

To test:-

1: Set the camera body to exposure mode M - manual.
2: Ensure you have enabled the use of the aperture ring in the custom menu.
3: Set the aperture on the lens to a small aperture (big number), f22 or similar.
4: Press the green button but as you do so, look into the front of the lens where you should see the diaphragm/iris close, and open again. This action should set a shutter speed that is appropriate to the aperture to give a correct exposure value.
5: Change the shutter speed manually to a duration of 1 second or so. We are only testing the mechanics here, you will not get a correct exposure.
6: Still looking into the front of the lens, take an exposure and observe the diaphragm/iris. It should close for the duration of the exposure, then re-open to full aperture.

If the mechanics works as I have described, all would seem OK.

Now choose a subject, set an appropriate aperture for the required depth of field, repeat steps 4 & 6, omitting step 5, and point the lens at your subject, not yourself. You should now have a correctly exposed image of your subject.

To answer your question simply, the DA* 55mm SDM lens has roughly the same field of view on a Pentax DSLR to the de facto standard 85mm focal length for portraits.

The softness preferred in portraits can be achieved easily in post processing.

Just buy one, you know it makes sense.

Now you're being silly

For those who have expressed an interest in seeing images taken with the SMCP 500mm 1:4.5 lens:-

Long distances guesstimated with the help of Google Earth.

Any focussing issues are down to my poor technique and a less than sturdy (borrowed) tripod and not the lens.

Farming activity - Straight line distance approx. 1/2 mile




Caradon Hill TV Mast (Cornwall) - Straight line distance approx. 2.5 miles




Disused engine houses - Straight line distance approx. 2.5 miles




Blackbird at about 20 yards




The birds are Buzzards at about 1/2 mile and they are in the shot by pure accident




These and the remainder of the images can be seen here.