[Douglas_of_Sweden]

It appears that there are m42, K, M and A versions of the Pentax auto bellows. The difference between the m42 and the others are obvious, but not even Dimitrov says anything about the differences between the bayonet versions. On the rest of the web, I get only unclear contradicting clues. And I can't get anything out of the search function of pentax forums either (not saying that it isn't there, but I can't find it). I have book literature on the "manual" versions, but non on the A version.

It appears however from some web links and ebay posts etc that there are versions that was sold as K, M and A respectively. But where there any change between them, other than perhaps cosmetically.

I'm quite sure that the K and M versions are identical (except new box and perhaps some cosmetic difference. But since there is an A version, am I to presume that it has transfer of the A contacts for min/max apperture etc??? I have seen no photos that convince me of this.

Also, I'm not sure that any of these have even mechanical apperture transfer (so that one could meter with the green button on a DSLR)?

Greatfull if someone can enlight me!

Try to avoid draging the other Pentax bellows into the discussion. I have the Bellows II and a third party Bellow that transfer the apperture mechanically. Now it is the auto bellows that I want.

PS. Does anyone know if Pentax made these Bellows by themself? Or had someone else do them? The reason I'm asking is that they look almost identical to my Konica AR bellows! Macro slider, lens reversing, finnish... DS

[SOldBear]

No version of the Pentax bellows supports pKA mount.

All versions (K/M/A) are basically the same. The (minor) difference is in the reversing adapter shipped with the bellows.

On all versions, there is no "transfer" of aperture value. You set the aperture using the aperture ring on the lens, and close it down just before shutter release with a double shutter release "cable." Of course this does not work with lenses without aperture ring.

I have the M version, but have not used it since I acquired the extension tubes and later macro lenses. I recycled the bellows rail into a macro focusing rail.

Pentax has never made any extension tube that supports pKA mount either (even though third parties do make them).

Note: in the manual of the "Auto Bellows A Pentax," page 2, "When you use a Pentax A lens, set the aperture ring at each f-number and do not set it at the "A" (auto) position."

[Douglas_of_Sweden]

Thanks! This is what I suspected. Question is if it is worth bothering to get one if I have to shoot all manual. My 3rd party bellows allow meetering with the green button, and hence focusing full open, which is very handy. Sure the auto bellows have the macro scales, rails and advanced lens reverse feature...

[Nass]

Very old thread but I was googling myself about the difference between -a and -m bellows. Just for the record, the x bar in the middle is a slightly different width on the -a version to the -m version. So that means parts are not quite interchangeable. The accordion in my -m version just went so I bought an -a one, but can't reuse the smoother bottom adjuster from the -m version on the -a one.

[67pentax67]

hi,
i have bought a Pentax autobellows A and slide copier A for 35mm K1000 camera, but the kit does not contain the L shaped metal gauge / measure
does anyone know if i can use another from any of the K or M kits and this would work with the A kit? cheers in advance,

[Not a Number]

Asahi eliminated the 55mm lens scale in the "A" bellows and removed the magnification markings on the 50mm lens scale. Otherwise the marking line up with the scales from the screw mount Auto Bellows scale and are completely interchangeable.

I did not know they made changes to the "A" model X-frame.

[67pentax67]

many thanks ! i will be using a 50mm SMC lens on the K1000 does it matter if Pentax have removed the magnification markings if all i am doing is copying 35mm slides?
cheers again

[Not a Number]

K1000 film camera? Set the extension at 52mm and the slide copier according to the table from the manual attached below. If you are using a digital with a APS-C sensor the rail isn't long enough to get a full frame image so you need to come up with a way to make the rig longer. There are various posts on this.

[67pentax67]

brilliant, thanks very much indeed

wont i need the L shaped ruler/ frame to get the 52mm? i could use a steel engineers ruler?

thanks again, much appreciated,

[Not a Number]

Just eyeball it through the viewfinder. There is some cutoff due to the frame of the slide. The camera viewfinder doesn't show 100% either. So you have to make some adjustments.

[67pentax67]

i see, ! so the ruler/ scale just gives an approximate distance ? and what matters is what i can see through the viewfinder?

im guessing just test a film with slightly different distances and see what i get?

im using slide film to copy slides, i wondered if you knew what speed is best,

thanks very much for all your help, MUCH appreciated!

[Not a Number]

The scales are fairly accurate in terms of extension, perhaps withing 1/2 a millimeter or less. They took the magnification markings off the "A" scales as it depends on the lens in uses - different optical formulas with different optical "centers". They are good for quick setup. I rarely use the scales except to get a ballpark figure of the magnification. They are a bit of a nuisance because they can extend over the lens and hit the subject.

[indykpol]

My 3rd party bellows allow meetering with the green button

Which 3rd party bellows are you using @Douglas_of_Sweden ?