What does this scale indicate??

[Michael H. Cothran]

I just bought this Zeiss CF 135mm Makro Planar plus Hasselblad auto bellows off Ebay. It is destined for use on my X1D whenever my Kipon adapter decides to arrive. In the time being -

Question - As you can see, there is a scale running along the base of the rail, in mm markings. Runs from 70 - 200mm. Does anyone have a clue as to what this scale is indicating? It's definitely NOT a distance scale. What could it be for?

Thanks

[NickT]

Hi Michael I think that is telling you the length of the bellows extension?

[ChrisL]

Nick is correct but only under certain circumstances.
The attached lens (except the 135mm see below) must be set to infinity, then the scale reads the extension, from that tables are available to calculate the magnification factor and the exposure compensation required.
Hasselblad made a calculator, like slide rule, so you could enter the magnification you wanted and read off the extension required using tubes, Proxar lenses or bellows, depth of field is also shown. You could set any parameter you wanted fixed and read the equivalent variables.
135mm is marked on because that lens has no focusing helical and can cover a range from infinity to 1:1 on the bellows. (You need f11 at infinity for anything decent as is computed as a close up lens primarily)

[Michael H. Cothran]

Thanks guys. Nick & Chris - I can see where those markings do show the extension (in mm) of the bellows, but they still make no sense to me for use with the 135 lens, for which this bellows was specifically produced.

I understand the principles of magnification, whereas if you extend the lens a distance equal to its focal length, you will have achieved a 1:1 mag ratio, which will then require 2 full stops of exposure compensation. For example, if I add a 100mm extension tube to a 100mm lens (while it is focused at infinity), I'm at 1:1. So, for my 135 lens, I need to be extended 135mm to achieve 1:1.

However, if you notice in my picture, the bellows is already extended to the 130mm marking, which should basically be a 1:1 mag ratio, requiring a 2 stop exposure increase. But, according to the scale, where the bellows is right now only indicates a 1 stop exposure (which should be for a 1:2 ratio), and is only about half way extended. Please correct me if I'm wrong, but I believe I have to extend the bellows fully to the 200mm setting in order to achieve 1:1 with the 135 lens. Meaning, these numbers on this scale just don't jive. I'm starting to get a brain-ache!

[ChrisL]

On the auto bellows the 135mm lens is in focus at infinity at the closest extension of 63.5mm at the longest extension of 202 mm (8 inches) it covers 6x6 for 1:1 reproduction with an exposure factor of 2.
The 135mm lens has no helical so the "offset" from the lens flange is 63.5mm that plus the focal length (actually 137mm) = 200.5 ( I think the difference to the 202mm is because the coverage on film is actually 55mm not 6cm. so you need a touch more for true on film plane 1:1.
This why the extensions with other lenses refer to the infinity setting on their helical, they do not (unlike the 135mm) focus to infinity on the bellows, you have added 63.5mm to them already. You would, correctly as you state, extend the 100mm lens 100mm to get 1:1 the 135mm only starts at infinity with an 63.5mm extension applied so you add that on as well, the markings are correct.

The helical focus extension on a Planar CF 100mm is from 0 to 16mm (0= infinity 16mm gives closest focussing point at maximum helical extension, the 135mm lens has no helical so in effect its 0 extension is at 62.5mm when mounted on the bellows (effectively giving it a helical focussing mount) does that help or confuse further? (The macro planar 120mm extends from 0 (infinity) to 27mm on its own helical in comparison to that 100mm Planar lens giving it the Macro reach)

[Michael H. Cothran]

Wow. I guess that explains it all. Thanks ChrisL.

[ChrisL]

U

Wow. I guess that explains it all. Thanks ChrisL.

Unfortunately it doesn't improve my images 
Enjoy, lots of fun to be had and so much easier with digital and live view, I sold my manual bellows set up years ago for a mere pittance: "Regrets, I've had a few" 

[Bashir Lunat]

I just bought this Zeiss CF 135mm Makro Planar plus Hasselblad auto bellows off Ebay. It is destined for use on my X1D whenever my Kipon adapter decides to arrive. In the time being -

Question - As you can see, there is a scale running along the base of the rail, in mm markings. Runs from 70 - 200mm. Does anyone have a clue as to what this scale is indicating? It's definitely NOT a distance scale. What could it be for?

Thanks

To add to excellent replies already given, I bought similar combination few months ago and as I already have a variable extension tube,this lens can be used as a normal lens also. The price varies around £ 250 and it can be used with majority of c or cf lenses.

[Michael H. Cothran]

Thanks, I am familiar with the 64-85 variable extension tube. In all candor, it really is more practical to use, and certainly easier to lug around in your camera bag. However, on the downside, it does not allow you nearly as much focusing range as the bellows. Still, I may ultimately buy one from Ebay, just for the convenience.

I also still have a CF 250 Sonnar which I also plan to use with the bellows. This should allow the 250 to focus down to 1:2, which should open up a whole new world of imaging possibilities.

All of this is contingent upon getting the Kipon Hass>X1D adapter from China, which I ordered 3 weeks ago. Still no word, but they originally stated shipping anytime up to Dec 27. So, like everything X1D, it seems, I am patiently waiting.

[Bashir Lunat]

Michael, I added two shots to show what 135mm looks like attached to variable extension tube.

[Domip]

So much easier with XCD 120macro... But I know the price... but once paid, you can forget about it and enjoy the ease and perfection of this modern SUPER lens!