A Question for 65mm f8 Super Angulon Owners

[Steve Smith]

I now have a replacement shutter for my 65mm f8 Super Angulon. The new shutter was fitted with an 80mm lens and has an aperture scale which starts at f5.6. I can't swap the scales as the old shutter had a Linhof Select front plate with integral engraving.

If anyone has this lens, I would appreciate seeing a couple of pictures of the aperture scale taken with the lever at the two extremes of its travel. If I can see how far before f8 and after f45 it goes, I should be able to make a new scale.

Thanks.


Steve.

 

[Ian Grant]

Will do the photo tomorrow (if no-one does one sooner). Remenber that a scale is relative because the aperture is related to the diameter of the f stop as well as the FL. So the gradations betwen stops are the same it's the f no & position that will differ.

You could back calculate very easily and accurately. The #00 shutter has to be stopped down quite a way before it reaches the f8 max aperture of the 65mm SA.

Ian

 

[SMBooth]

Not sure of the photo you want, mine is on a Synchro Compur and f8 lines up with 1/250 shutter, while f45 lines up with 1/8.

 

[johnielvis]

I have a linhof one--it's real easy--you need no photo--f45 is closed down all the way as far as my shutter goes

f8 is opened up so that the iris just disappears behind the glass (it gets bigger after that but you can't see it).

all the in-between markings are equidistant--that is--f8 to f11 is same distance as 11 to 16 and 16 to 22 and 22 to 32 and 32 to 45....so just subdivide in exact divisions and you're there...that is if your 00 is same as my linhof 00....

 

[Steve Smith]

f45 is closed down all the way as far as my shutter goes

I recall that mine went a bit past f45 but I could be wrong.

Remenber that a scale is relative because the aperture is related to the diameter of the f stop as well as the FL. So the gradations betwen stops are the same it's the f no & position that will differ.

I am about 90% certain that the f5.6 to f32 marks I already have will translate to f8 to f45 with the SA fitted. Hopefully a couple of pictures will confirm this.

The #00 shutter has to be stopped down quite a way before it reaches the f8 max aperture of the 65mm SA.

Yes. Looking through the lens, you can tell that closing down the aperture initially doesn't do anything until the blades cover the relatively small element facing the aperture blades.


Steve.

 

[Ian Grant]

I recall that mine went a bit past f45 but I could be wrong.

I am about 90% certain that the f5.6 to f32 marks I already have will translate to f8 to f45 with the SA fitted. Hopefully a couple of pictures will confirm this.

Yes. Looking through the lens, you can tell that closing down the aperture initially doesn't do anything until the blades cover the relatively small element facing the aperture blades.

Steve.

Wrong way around, a 65mm lens has a shorter focal lenght than an 80mm so focusses closer to the film plane, so because of the Inverse square law in fact f11 on the shutter scale for an 80mm lens translales to f8.9 when a 65mm lens is used.

Having found my 65mm SA it's impossible to make a useful image unfortunately, first the front cells won't budge but more importantly it's Linhof select and there' nothing to relate the scale to.

Here's the calculated changes:

80mm scale	65mm f stop
8	6.5
11	8.9
16	13
22	17.8
32	26
45	36.6
9.8	8
13.5	11
19.7	16
27	22
39	32
55.4	45

You could make a new scale and stick it on the lens, it needs shifting so the new f11 relates to the in-between 8.9.

Hope that helps

Ian

 

[Steve Smith]

Thanks to all.

It actually seems to be simpler than I thought. Using the simplistic aperture diameter = focal length divided by stop rule means that I can work it back from what I have to what I want. The figures are the same as in Ian's table.

Just to satisfy myself, I drew it up. First image is logarithmic, second is linear.

Basically, if I place my new f8 about half way between the existing f8 and f11 it will be about right. Certainly more accurate than I can meter!


Steve.

 

[Steve Smith]

I have a linhof one--it's real easy--you need no photo--f45 is closed down all the way

Ian, is this the same for yours? If so, it will give me some assurance if my f45 ends up in the same place!


Steve.

 

[Ian Grant]

Ian, is this the same for yours? If so, it will give me some assurance if my f45 ends up in the same place!

Steve.

Just checked and yes f45 is the minimum it'll stop down to. Luckily f stop markings on rimset Compur, Copal, Epsilon, Prontor are evenly spacesd. older dial set lenses have scales which are circular versions of your second drawing.

Ian

 

[Dan Fromm]

Luckily f stop markings on rimset Compur, Copal, Epsilon, Prontor are evenly spacesd. older dial set lenses have scales which are circular versions of your second drawing.

Ian

Ian, have your vision checked.

I just took a look at some of my shutters. Rimset Compur (Compur-Rapid #0, Synchro Compur #0 and #1), uneven spacing. Prontor Press #0, even spacing, #1, uneven. Copal Press #0 and #1, even, Copal cock-and-shoot #0 and #1, even. Epsilon (not sure where it fits in the Compur/Copal scheme, it holds a 105/3.8 Xpres), uneven.

With uneven spacing, the smaller the aperture, the shorter the steps.

 

[Ian Grant]

Ian, have your vision checked.

I just took a look at some of my shutters. Rimset Compur (Compur-Rapid #0, Synchro Compur #0 and #1), uneven spacing. Prontor Press #0, even spacing, #1, uneven. Copal Press #0 and #1, even, Copal cock-and-shoot #0 and #1, even. Epsilon (not sure where it fits in the Compur/Copal scheme, it holds a 105/3.8 Xpres), uneven.

With uneven spacing, the smaller the aperture, the shorter the steps.

Yes you're right my mistake - on the small shutter on the 65mm SA which I dhad in front of me the spacings appear to be almost even but they aren't quite.

Ian

 

[Steve Smith]

A member of the large format forum sent me some pictures of the aperture lever at both extremes of travel and also one of the front with the front lens elements removed so I could see the aperture blades relative to the rear lens elements when set to f8 (i.e. not quite covering any of the lens.

My conclusion now is that the scale I have fitted to the shutter is not for the 80mm lens elements it had fitted to it as my actual f8 position is half way between f5.6 and f8 on the old scale rather than between f8 and f11 as previously calculated.

The elements this shutter had are an 80mm Componon which is an enlarging lens which wouldn't normally be fitted to a shutter so I now think that it was wrong to assume that this scale matched the 80mm lens.

Anyway, it's now time to use it!


Steve.