How to use a triple convertible lens.

**Louis Pacilla** · 22-Jul-2013, 11:26

Originally Posted by Ari

Jumping in here with a question regarding the Turner-Reich convertibles.

I have a 12-21-28 and I'd like to know if anyone has a link for using it in its multifarious configurations (couldn't find a definitive link).

Thanks

Hey Ari Here's a fairly informative read from the company angle. You may have already viewed these but if not they are worth looking over. 1922 Gundlach-Manhattan Optical Co Catalog http://piercevaubel.com/cam/catalogs...ndmanlp286.htm 1925 catalog http://piercevaubel.com/cam/catalogs...ndmanlp407.htm and the 1932 catalog http://piercevaubel.com/cam/catalogs...dlachlp334.htm

**Ari** · 22-Jul-2013, 13:14

Hi Louis,
Yes, I have seen that, thanks for passing it on.
I fear I've hijacked this thread, unless the OP was satisfied with the advice he was given.
Going to play with the T-R now!

**Peter Gomena** · 22-Jul-2013, 16:48

Using a strong yellow filter with the single elements of a triple convertible will help minimize some of the chromatic aberration. I used a #15 yellow with my Wollensak triple convertible and it helped quite a bit.

On the other hand, you may like the softer look - it depends on what you're after!

**Ari** · 22-Jul-2013, 19:48

Originally Posted by jnanian

the front element removed is the mid-focal length ( in your case 21 " )

Just wanted to add to what John wrote; the front element removed, with the rear element placed in front gives the medium focal length; at least it does on my T-R 12-21-28.
Thanks again, John.

**Dave Henry** · 23-Jul-2013, 21:56

Thanks everyone for all the explanations. I will use the 12 and 18 and bypass the long element for the time. The suggestion on a yellow filter was also great. The Ilex shutter has all three focal lengths with f/stops engraved on it and both cells have the focal lengths engraved on them so no problem figuring that out.

The 1/50 sec measures out to 1/25 sec and considering the comments on #5s being slow, I'll just leave it that way. All my lenses on my 2D are in #4s and I have faster speeds with them.

I will experiment with the rear cell on the rear as well as front. But, at $3+ per sheet, I'll be taking a lot of notes!

This camera is heavier than my 2D and the board is 7". I'll take my 2D lenses with me and play with them as well.

Have a great weekend and thanks again everyone.