TT&H Cooke lens

[seawolf66]

I gotten a TT&H Cooke lens ,But not able to clarify it as to which it is:
since on Seth's site I find the mention of a TT&H Cooke lens for 5" 6" and 7"
But can not find any thing on a 61/2 inch Cooke F-4.5 lens There are references to series II lens
one is on the page 11 on the following site http://www.cameraeccentric.com/html/info/cooke_1.html
and then on page 22 of same book. So the question is it a plain Jane or is it
an Aviar unmarked ? will be able to supply photo's upon receipt of the lens:
thank for your time and information

Have tried the Cooke web site for information

[IanG]

Some TTH Cooke lenses were made for specific camera manufacturers like Thornton Pickard and so are not listed in the TTH Adverts/Catalogues etc. In addition some of these Cooke lenses were older triplet designs while lenses of the same name sold seperately were 4 or more elements.

There was a Series IIa f3.5 6.5" it's listed in a 1921 advert in front of me.

Ian

[eddie]

pictures are worth a 1000 words.....

[Struan Gray]

A triplet has three bits of glass and two air spaces, an Aviar has four bits of glass and three air spaces. Count the number of strong reflections and Bob's yer uncle.

Actually, it can be hard to be sure you haven't missed a reflection. One solution is to use a laser pointer, which works *much* better than a lamp or spotlight. Another is to see if the lens is symmetric front and back. Aviars are, Cooke triplets are not - one of the 'problems' with a triplet is that the perfect design can end up wanting the aperture iris in the middle of the centre element.

[seawolf66]

Eddie: As soon as I have it , I will post a photo or two Here: Lauren



pictures are worth a 1000 words.....

[seawolf66]

73158731597316073161Eddie here are some photos of it,
Its a TT&H cooke 6-1/2inch -at F-4.5 the rear elements are marked with the same number's a F.L.
the brass ring has TT&H on it: the rear element does unscrew from the body and the front does not
the retaining ring in the lens has the same number written in pencil on it: Also came with front and rear caps : that fit tight


pictures are worth a 1000 words.....

[Mark Sawyer]

Looks like an Aviar from the size of the rear barrel. The proof will be in whether the rear section has one element (triplet) or two (Aviar).

[seawolf66]

I have a little fear of maybe scratching the lens since their very nice and clean and scratch free:
tried but scratched the brass and non of the two ring's budged on the rear cell:



Looks like an Aviar from the size of the rear barrel. The proof will be in whether the rear section has one element (triplet) or two (Aviar).

[cowanw]

Cooke nomenclature seems very confusing with two series ll lenses at the same time.
I have an 10.4 inch Series ll anastigmat which is a triplet.
If you close the aperture down and look at the back with a ceiling light above you, you will see either two reflections of the light (triplet) or 4 reflections (Aviar).
I am sure others will chime in with a more refined technique.
It does look like there are two cells on the back

[cowanw]

PS The whole back may screw out of the shutter, not just the glass. You don't need to take out the retaining ring holding the glass in the brass sleeve cell. ( if I have interpreted your scratch comment correctly)

[IanG]

If I was a betting man I'd say that wasn't a triplet and put my money on it, the rear element cell of Triplets are usually much smaller. Also it is a Series II Cooke Anastigmat.

Ian

[seawolf66]

One there is not a shutter only iris in brass and glass lenses, if you look at the fourth photo it shows the barrel without rear lens


PS The whole back may screw out of the shutter, not just the glass. You don't need to take out the retaining ring holding the glass in the brass sleeve cell. ( if I have interpreted your scratch comment correctly)

[seawolf66]

ok with Iris shut down to F-16 I get four reflections. as for the two series two from Cooke the second on page 23 is a portrait lens so they say , because it starts with a 10 1/2inch lens and goes to 18inch lens
which is what they call their series II portrait lens. On page 11 of the same booklet they state their series II is a fast lens and that one starts at F-4 1/4 inches going to 8 inches
that's the only difference I can find between them two :



Cooke nomenclature seems very confusing with two series ll lenses at the same time.
I have an 10.4 inch Series ll anastigmat which is a triplet.
If you close the aperture down and look at the back with a ceiling light above you, you will see either two reflections of the light (triplet) or 4 reflections (Aviar).
I am sure others will chime in with a more refined technique.
It does look like there are two cells on the back

[cowanw]

Four reflections is an Aviar. There will be four on the other side of the iris as well.
Have a look at this site.
http://www.cookeoptics.com/cooke.nsf/news/viewcamera2002.html
About a third of the way down you will see the part on the Aviar describing the
"The Cooke Aviar Series II f/4.5 ... lenses are of what lens designers call the dialyte type of lens construction. This consists of two air-spaced achromatic doublets, the two outer ones double convex, and the two inner ones double concave."

[IanG]

The Cooke website is a little wooly on dates. They mention the new range of Series II Aviars as being 1924 on one page and 1921 on another, the BJP Almanac Cooke adverty for 1921 lists the Aviars. There was an earlier Series II Cooke same f4.5 aperture and focal lenghts as well.

Nice lens Lauren

Ian

[Steven Tribe]

This is not a hijack!
I was cleaning a aviar 6 5/8" for listing when I realised this was a slowed down version F6.3.
It is a dialyt design.
I can only find this type post WW2 and coated? serial number is 112080.
Have I missed something in VM?

[IanG]

Your 6 5/8" f6.3 Series IIIb Aviar lens is listed in the BJP Almanac 1927 TTH Adverts, want me to scan the page ?

Too late the scanner was next to me so I've done it :D

73220

It appears from a 1951 advert that both series of Aviars were improved and passed a series of Government tests with regards to their sharpness and definition. I'm sure I've something about this and their coatings in a post WWII BJP Almanac.

Ian

[cowanw]

way cool

[Steven Tribe]

Thanks Ian!
I found the Aviaric in VM but was puzzled by the clearly engraved Aviar designation.
It is very well put together for a mass produced item.

[IanG]

Thanks Ian!
I found the Aviaric in VM but was puzzled by the clearly engraved Aviar designation.
It is very well put together for a mass produced item.

If people called the lenses of any make by their order codes it'd be a nightmare :D Meyer lenses of about the same era had a different order code depending on which FL as well as shutter.

TTH never made an Aviaric.

Ian

[seawolf66]

Steve: How much trouble did you have getting those ring retainers out :

[IanG]

Realised my comments could be taken the wrong way :D I was commenting about the vagueness of the VM which in this case is inaccurate.

Ian


If people called the lenses of any make by their order codes it'd be a nightmare :D Meyer lenses of about the same era had a different order code depending on which FL as well as shutter.

TTH never made an Aviaric.

Ian