ID This Brass Lens

[Fotoguy20d]

Sorry for the lousy photos - they're from the seller. It seems to be an f8 and says Extra Rapid Aplanat No 3 and below that Series G? From the design/construcion of the lens and the text, anyone have any thoughts as to who made it? I'm figuring its a European maker - it's an aplanat not an RR, and it says serie, not series.

Eventually it'll show up and I'll be able to figure out its focal length and what it covers but I'm guessing around 9-10" and whole plate.

Thanks,
Dan

[Steven Tribe]

Well, it was sold on the German market.
Busch reached serie E, Goerz reached series F but no ideas about who made a serie G! The curved transition from barrel to hood might give someone an idea?
Tradition at the time was that size 3 around 13x18cm to 18x24cm (small stops). The much sold Busch serie D was 26cm efl.

[Fotoguy20d]

Steven,

I hoped you would have some ideas. I couldn't find a series G in the VM. Maybe there will be more clues once I get the lens in hand. It definitely looks like a G, right?

Dan

[Fotoguy20d]

Not that it means anything, but the script "Rapid" on this lens does not seem to match the style of my Rapid Paraplanat by Goerz. Also, doesn't match any Busch lens I've seen.

Dan

[Steven Tribe]

A "G" I think!
First thing to do is to check the F. An "extra rapid" could be an F6 rather than the usual F7.7 - 8.
I would also have guessed that this is really right size for a full plate camera. Sometimes, apparently anon. lenses are identifiable.
The enclosed, also a size 3 extra rapid, was given a name through the VM! A German lens, given a French engraving sold in the UK market! Made by Steinheil.

[Fotoguy20d]

Steven,

The lens arrived today - I will need to clean it up and mount it in a board and will put it on my 8x10 next week (after the hurricane blows through). A quick projection onto a wall suggests the focal length is around 12". But, the aperture, which is marked f8, is only 7/8". Perhaps my crude measure of 12" is optimistic, and this is actually an American system f8? Not that it would be very "extra rapid" at more than f11...

Dan

[Fotoguy20d]

Taking it outside on my 2-D, it's around 10 1/2 - 11" in focal length, and its definitely dimmer than an f8 RR so I"m guessing that f8 marking to be the US system. But, its marked extra-rapid... Even wide open, its illuminating 8x10 although I don't know if I'd call it covered.

Dan

[Steven Tribe]

I don't understand this!
Are both lenses two glass achromats? Some periscope designs were called (periscope) aplanats.

[Fotoguy20d]

They look to be two identical doublets. The focal length of each is around double the pair (from cursory projection onto a wall). I will need to compare the angle of view of this lens to others I have of similar focal length (#2 Goerz Paraplanat, 12" T-R perhaps) but I don't believe it to be particularly wide. I suppose compared to an f14+ periscop, this would be considered extra-rapid.

Dan

[Steven Tribe]

Your #2 Paraplanat has a efl of 21cm. 8 1/4". Will cover full plate at lower stops. 80 deg coverage and F7.5.
What are you measuring with - a shrinking tape measure!!?

[Fotoguy20d]

Then I probably don't have the #2. Mine covers 8x10 at around 150' focus distance at f32 (from experience) and I thought it was longer. I also have a WP Manhattan optical RR to compare with.

[Steven Tribe]

#3 paraplanat has efl of 27cm and covers 8x10" and up to 11x13" at small stops. My list doesn't have any larger!

[Fotoguy20d]

Steven,

I believe you gave me a copy of that sheet back when I got the paraplanat (which I've only used once or twice). I'll need to look at the lens again and see which one it is.

I'll take some photos of this mystery lens - not that I really believe it would be so (since the barrel is engraved for the aperture scale), but maybe the aperture was added later using the waterhouse slot. The glass measures around 32mm diameter so at f8, that's around 10" focal length.

Dan

[goamules]

... but maybe the aperture was added later using the waterhouse slot. The glass measures around 32mm diameter so at f8, that's around 10" focal length.

The lens looks factory made with an iris to me. Unknow maker, there were probably hundreds of shops cranking these out, and most aren't named that I've seen. I've seen dozens just like yours, but none are marked with how made them, and all have slightly different engraving and such.

As far as the speed, you're saying the glass is about 32mm or 1.25 inch. You said it's a 10 inch focal length, so 10/1.25 = F8. How were you measuring the iris before when you said it's only 7/8 inch? You are supposed to look into the front glass, and measure the apparent size of what you see of the iris circle.

[Fotoguy20d]

Garrett,

That's the problem. When I look from the front, the iris is clearly smaller (maybe an 1/8" around) than the glass. And my perception is that the lens is dimmer than an f8 RR. Now that the hurricane has passed, I'm going to play with the lens and see how it compares.

Dan

[Fotoguy20d]

Here are two shots with this lens on 8x10 paper. First is at f8, the second at f32. Coverage is just shy of 8x10 at f8 (interesting how it swirls a bit) but coming in nicely by f32. I suppose Garrett is right and its just a no-name Aplanat, around 10 1/2" FL, covering 8x10 stopped down. I can live with that. It's a pity I blew the exposure on these - at f32, on the GG, the number above the door on the house across the street was nice and sharp.

Dan

[Ole Tjugen]

Rodenstock managed to get all the way to Serie L in Aplanats, so that's one of about a hundred possibilities.