Bellows question

Moderator: I wasn't sure where to put this question, you may need to move it.

Could anybody please tell me the principle differences between the K, M, and A variants of the Pentax bellows/slide copier systems. They all look very similar to me and I don't think the letters correspond with the three lens variations having the same lettering (No A or M implies K).

Thanks in advance.

The placing of the post is fine, I'm sure someone will pick it up.

Sorry I can't help - not my area of expertise!

Short of having all three to look at at the same time, I'm not hopeful of anyone answering this query. The only difference as far as I can see is that the K is for K series cameras/lenses, M for M, and A for A series. But the Bellows A surely doesn't have the electrical contacts and can only be used as an M lens anyway, aperture needs to be stopped down for a meter reading. I'm not sure there is much difference in respect of lens mount and operation between K and M cameras/lenses anyway.

K and M lenses have exactly the same mount. The M designation only means a "compact lens" specifically designed to complement the diminutive size of the M series cameras.

A series lenses have electrical contacts and an "A" setting to enable use of shutter priority and program modes with the A series cameras.

I don't think that any of the pentax bellows or extension tubes make use of the electrical contacts, but I'm not 100% sure, so others will have to confirm that....

John,

With your knowledge of the various 'K' mounts, if we suppose that the 'A' variant of the bellows does not have the electrical contacts (and I can't imagine that it has), can you take a guess (I won't hold you to it ) at what the differences in the 3 bellows might be, purely from a mount perspective. I'm beginning to think that all 3 bellows are actually the same, and they each acquired a new name as the various bodies/lenses were introduced.

I haven't any K Lenses to look at but am I right in thinking that if you were to look at the body mount of the lens, ignoring the electrical contacts of the 'A' series, they all look pretty much the same mechanically ?

I have no knowledge of the predecessor of the bellows M which you have referred to as bellows K, but there was a bellows III which was a simplified version of bellows M. The latter had a twin cable release which operated the camera shutter and the bellows mounted lens stop down at the same time. The III unit did not; how it was used in practice I have long since forgotten. However given how tricky it is to operate the bellows M with an *istD I'd not fancy going one further step back in time.

You may care to note that the bellows M can only just be fitted to an *istD, it gets within a whisker of fouling the body and needs great care to assemble it without damaging the camera. I have no idea if it will fit the later DSLRs.

Like you I suspect that bellows A was a marketing ploy to make it look more up to date than it was.

Thanks for the info Malcolm.

One forum member has suggested fitting a short extension tube between bellows and camera, which I thought was a good idea and I'll try it when I'm reunited with my bellows unit next week. I can't think of a reason why it shouldn't work, except the magnification scales would probably be inaccurate but that's a minor issue for me.

Its actually impossible to fit the bellows (I think mines a K) without an extension tube to my MZ-S which peeved me a bit. The bellows fouls the body below the lens mount. One product, it seems, where backward compatibility went out of the window. I think we can forgive Pentax for that 'though.

[quote="malcolmk"]I have no idea if it will fit the later DSLRs. quote]

I haven't actually tried fitting my bellows to my istD, but I did fit it to my istDS some time back and I think I had to take the bellows to body mount off of the bellows first , then reassemble the bellows after fitting that part to the camera. Whilst it wasn't as easy as it might have been with an older camera, I don't remember it being too difficult.

I'm rather thinking that not too many people use the bellows attachments any more perhaps because tubes and/or reversed and/or stacked lenses or any combination thereof produce similar results. Thinking about it, a dedicated macro prime lens is probably a lot simpler to use.

It is as you say best to to fit the body mount first. The trickier bit is that the bellows must be fixed absolutely 'square on' to the body because the clearance is literally 'fag paper thin' and if not 'square' the bellows rubs against the camera body. You also can't fit the magnetic scales because they actually do foul the body, not that they are a lot of good, being designed for full frame cameras.

You should 'think about' the macro lens again, the bellows can get a higher magnification. Much simpler though!

PS. I've just checked through my old Pentax catalogues and found both the M and the A bellows. The pictures, specification and description of facilities are identical on both.

Already done, I ordered a SMC-FA 1:2.8 100mm Macro from Ffordes yesterday.

Correction: it's the F version I have bought, not the FA, still too pricey, even on eBay.

I have the F4 100mm M series. Bought it new circa 1981 and still more than good enough for me.

Exellent lens but they are quite pricey to acquire at the moment. The decent ones (according to the descriptions) go for around the £100.00 mark, some as much as £150. I bought my SMC-F for not much more than that.

This one caught my eye
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7590873209&ru=http:...

and I thought, who in their right mind would put screw holes in a £600 lens. I know I wouldn't have the bottle (no pun intended).

Still, if it stays at about the price it is now ($95'ish) it'll be OK for manual focus work as long as there is no swarf rattling around inside.

Digging further through my file of Pentax brochures I see the K1000 shown with 'Auto Bellows', the ME series shown with 'Auto Bellows M' and the LX with 'Auto Bellows A'. As I said earlier, the spec and description of the A and M variants are identical. I have no spec of the non-suffixed version but the illustration appears to be identical to the later models.

In January 1983 (when the A version was current) the Pentax magazine carried a two page article on using the bellows attachments but did not refer to its suffix only the fact that there was an auto version and a manual version, the Bellows III. I conclude that all the auto versions are the same whatever the suffix.

Thanks Malcolm. I've only seen reference to the III variant and have no knowledge of it, but I'm reassured that somebody else, with more information to hand, has come to the same conclusion as me, that is that the A and the M variant at least, are one and the same.

Unless anybody else knows different . . .