You can also use the Symmar convertible by leaving the front element in place and removing the rear. Performance will not be as good as when using the rear element, but you will need a lot less bellows draw.Originally Posted by Darryl Baird
re: "240 / 420 - 500"
So my new 240/420 Symmar will require 1000mm of bellows to shoot 1:1?
That puts a tiny damper on my purchase( but then again I really wanted the shutter for the 305mm G-Claron, so the Symmar lens is a bonus)
Sandy
No, a 240/420 Symmar will require 500+420mm extension to shoot 1:1 with the rear cell alone. And about 480mm with both cells, which is generally better.
Not even my 30x40cm camera has enough bellows for a tight headshot with a converted 360/620!
I went over to the Cameraccentric site and copied the Symmar brochure (what a god send that site is...!!!). Here's a quote:
The Schneider Symmar f/5.6 is of almost symmetrical design and permits excellent pictures to be taken at a close range, even up to an image scale of 1:1 (natural size).
If the distance between the lens and the subject is shorter still, the lens should be turned.
The side with the **engraving should always point in the direction of the greater direction,** regardless whether it is the subject or the image distance.
~~~~~~~~~~~~~~~~~~~~
OK, I'm trying to navigate (in my head) this concept, but I think there is some other "rule" that may apply. If I want to shoot with the rear element (aka the 420 conversion) and I'm closer to the subject than 36" or 920mm, I should put the rear lens element in the front...? (it doesn't have engraving, so it is now turned/reversed towards the film/bellows rather than the subject). Otherwise it remains in the rear as in the normal two-element usage.
I love this stuff, but I do wish I'd studied a bit more math and the technical stuff regarding lenses... too much fine art training.
The rear cell alone isn't that optimised for anything, but it makes sense to reverse that too.
The 150, 180 and 210 are difficult to reverse, being in #1 shutters. The rest are easy - unscrew both cells, and mount each on the other side.
Ole, thanks. My "to test and to do" list just keeps getting longer everyday.
...keeps me out of (other) trouble I guess.
Wollensak may have had some of the last and best classic convertibles. Their Raptar 1A came in many combinations and made it well into the single coated age. I have a lovely 4X5 5X7 version languishing waiting for me to use it. (I simply don't get the 4X5 out very often.) It is 8 3/4" f7.7 / 12 3/4" f12.5 / 20" f16 all snugged into a modern Rapax #1 shutter. Maybe Goldfield later todayIt's mate that came on the same day is a gorgeous 150 Heliar, also untested. Shame on me.
I think the 210mm symmar is the perfect lens for me. I'm in the market for a 210 or 240 so the convertible part is just an extra plus. The longest rail i have is 21" so i wont quite get to a 1:1 with the lens, but i will definitely be able to focus closer than infinity on it. How exactly do you "convert" this specific lens? do you remove the back or front element, or reverse them?
Scott, you screw off the front cell.
Scott, the first thing you should do is see if you already have a convertable lens. Unscrew the front element of your 150mm and see if just the rear gives you an image at about twice the focal length. Any symmetrical lens is a convertable, and plasmats, probably the most common current design, are also convertable.
You'll want to do a test exposure to see if the resolution is acceptable, and you'll have to figure the new aperture scale, but that's not hard.
"I love my Verito lens, but I always have to sharpen everything in Photoshop..."
the 150 I have is a symmar-s, so i don't think it would work, but i will try! I've noticed that the non-S symmars are all older, a lot of them are in compur shutters and seem to be more expensive. How do they differ from the S lenses besides the fact that one is convertible and one is not?
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