Looking for information on two older lenses

[JLP]

Just adding a couple of older lenses to my bacpack.
One of them is unknown to me, an Aldis Brothers No. 20 11.5" f4.5 Serial number 143315
The other a Dallmeyer Pentac f 2.9 203mm no AM inscription, serial number 656841

The Aldis Brothers is in very good condition, black barrel, a little scratch on the front element and a single buble in the rear. Uncoated
What type lens is this and when was this made?

When was the Pentac made? the serial number is higher than those i have seen mentioned in this forum. The lens is just being shipped but should be close to new condition. Will keep me sleepless for a few days (Nights).

They are both to be used on a 4x5 the Aldis almost requiring an extra tripod but with a double lensboard i think i can fit it fine. Bellows extension no problem

Any information about these will be greatly appreciated

Thanks

 

[Dan Fromm]

The Vade Mecum's Dallmeyer chronology stops at around 340k, early post-WWII. Y'r Pentac is quite a late one, the tipoff for that is that the focal length is given in mm, not inches.

Y'r Aldis just may be a tessar type, made around 1929-30. But the VM's report on Aldis lenses is very muddled; I think the muddle reflects inconsistencies on Aldis' part.

 

[JLP]

Would the later Dallmeyer have lost some of it's "charm" or are they all about the same disregarding the various versions and manufacturers?
Would you know what shutter the Pentac could be fit into?
The Aldis was cheap even as a paperweight. It has 3 elements, front is positive on each side, middle (Close to front) is negative on each side and the rear is positive. Don't know if that is enough information.
Dan, thanks for the response.

 

[Dan Fromm]

JLP, a Pentac is a Pentac is a Pentac. Air Ministry Pentacs, rarely engraved Pentac, made by other makers are reputed to be a little worse, on average, than Pentacs made by Dallmeyer. I have the impression -- could be mistaken -- that once Dallmeyer had settled on a design, that was it. But your Pentac's serial number is well above 340k, which is roughly where Dallmeyer started coating.

As for the Aldis, its easy to confuse a tessar type with a triplet. If the lens has four strong and no weak reflections from the glasses in front of the diaphragm and two strong, one weak from the glasses behind the diaphragm it is a tessar type. If four strong and two strong, no weak, then it is a triplet.

Aldis made triplets too. I have a couple of f/7.7 Aldis lenses engraved Uno that really are Uno types (cemented doublet in front of the diaphragm, singlet behind) and an f/4.5 Aldis engraved Uno that really is a normal ordinary garden variety triplet.

To add to the fun, the VM says that Aldis made 11.5"/4.5 tessar and triplet types. Which is why you should count reflections.

My f/7.7 Unos aren't that bad, haven't tried the f/4.5 yet. So give yours a try, it might surprise you.

Cheers,

Dan

 

[JLP]

Well, as far is i can see it most likely is a Tessar, there's a weak reflection from both front and rear.
Hope to have a lens board ready in a few days so i can expose some film but it is a bit of a custome job since the retainer is larger than the outside of the board.
Just ordered the VM.

Thanks Dan..

 

[ineffablething]

The Pentac's are fun. And,as stated above, the Air Ministry clones are virtually identical. For some reason, people just want to pay for the Pentac name. Although I must say that prices for Air Ministry lenses have jumped exponentially the last few weeks.

 

[JLP]

Yes, what i have seen from the Pentac's looks intersting. There's an AM 8" going on ebay right now.
What size shutter would the Pentac fit into if any?

Thanks for the inputs.. It's much appreciated.

jan