Gundlach lens info

[thirteenthumbs]

<p>Another question, With the front element removed how far is it to the next glass surface? 1/3, 1/2 or 2/3 the length of the front barrel?</p>

[robbiebedell]

<p>With the front removed I would say it is 1/3 the length to the next glass surface..</p>

[thirteenthumbs]

<p>Then the front has 3 elements in it. Its a Triplet with a Dialyt front retainer ring installed.<br>

Two elements in the front would have the next glass surface 2/3-3/4 the length of the barrel from the front.<br>

The questions are What focal length and Who made it.</p>

[robbiebedell]

<p>In appearance (which I know does not mean much) the lens looks a lot like this one:</p>

<p>http://picclick.fr/Taylor-Taylor-Hobson-Cooke-Aviar-Lens-6625-192062629313.html</p>

[thirteenthumbs]

<p>Disregard my previous post, I wuz thinking like President T followed by a rump. (senior moment)<br>

3 elements in the front, 1 in the rear is 4 elements. DUH.</p>

[robbiebedell]

<p>Thank you Charles...you are not alone regarding such moments....</p>

[thirteenthumbs]

<p>2nd attempt.<br>

When disassembling lens, measure the length of the barrel and note the recess of the front and rear elements.<br>

After removing an element from one end of the barrel or the other note the distance to the next lens/glass surface.<br>

With your lens the diagram shows it should have 4 elements in 2 groups. <br>

Now you said that the next lens surface is approximately 1/3 the length of the barrel behind the front element and with one element visible close to the rear edge of the barrel then the barrel probably has 3 elements in the barrel, also called a cell. <br>

There are no lens diagrams for Gundlach that have 3 elements in front of the aperture and one element behind the aperature but there are several for Taylor in the Vade Mecum.<br>

The possible discrepancies are the wrong lens diagram is in the catalog or the front retainer ring is for a different lens, the latter being the more likely.<br>

But if it shoots good it doesn't matter much. A lens of that vintage should focus its focal length from the film plane. Measuring from the shutter/aperture blades to the film plane will give a ballpark accurate focal length measurement.</p>

[robbiebedell]

<p>Thanks Charles. I have the cleaned lens and it is all set and mounted tight so I really do not want to start unscrewing things again. But I have compared the reflections closely to my little 103mm Trioptar and the reflections are almost identical. I am beginning to think this really might be a Cooke anastigmat triplet after all. I am getting ready to shoot...just clearing my shooting area which doubles as a painting studio...so there is a lot of shifting of objects. I will post photos. I am sure you have seen this but here is the Cooke:<br>

http://www.cookeoptics.com/t/history.html</p>