I have a Symmar 210/370 convertible that I like. As a 210 it's a really sharp modern lens with smooth out-of-focus areas and a nice look for portraits on 4x5". I don't often use the 370 side, because I have a 360mm Tele-Arton for 4x5" and the 370mm configuration (rear cell only) requires more extension than my Tech V has to offer, so I need to use it on an extension lensboard if I want to use it that way, and I prefer to leave it set up on the flat lensboard, because it's cammed as a 210 with infinity stops set for the flat lensboard. The 370 isn't quite as sharp as a real 360mm lens, but stopped down it's still pretty good, and it could be practical if you have a camera with something like 20" of bellows, or if you're willing to deal with the extension lensboard.
I would think that if you wanted to put together a compact, lightweight setup for LF a good combo would be a Symmar convertible in the normal range for your format (150/265 or thereabouts for 4x5", 210/370 for 5x7", or 300/500 for 8x10), plus an Angulon (more compact, less costly) or Super-Angulon (sharper, bigger image circle, but much larger and more costly) at the wide end.
For 8x10", there's also the venerable Turner Reich Triple Convertible that Ansel used for a while (at f:64, all lenses start to look the same on 8x10"), usually something like 12-19-25", but there are a few different versions, it seems.
I have ended up with three of these, a 135, a 150, and a 210 and I rarely use any of them now for various reasons. Here is a totally subjective evaluation of my examples for 4x5 use.
The 150/265mm came on a Linhof I bought and it is a dog in all respects. At 150 it is just ok (and I have a tiny Fuji W that is much better) but converted it is almost unusable as it reminds me of holga images. I keep telling myself I will try it converted for a portrait lense or for turn of the century dreamy landscapes.
The 210/370 is a nice lense and I got many good images with it. It is prone to flare and is big but It gives good sharp images at 210mm. I don't have enough bellows to have used it converted. I replaced it with a modern coated Geronar mostly because of size and the shutter having quit on me. It is good enough that I paid to get the shutter fixed and am not sure if I will keep it but probably will.
The 135/235 is a nice little lens that I got for lightweight carry. I don't really need it but I like it at 135 and it is not bad at 235 with a some softness at the edges. I am happy to sometimes walk out with just this lens as a lightweight package but I am not looking for super sharpness when I do. I prefer and normally use a Fuji 125mm W (CMW?) for this length. I think I read somewhere that Wisner or his wife use this lens.
As you can tell I have mixed experience and it depends on what you want to use it for. I think my 150 led a hard life before I got it. Another example could be good.
Consider my observations as coming from someone that does little or no testing but simply looks at what I get from the lens. I don't understand why these lenses are so maligned by some but they are. Check the Photo.net archives as there is a lot there. I think if they didn't claim to be convertible that they would be held in higher esteem for a lens of their age. There are certainly better lenses and the prices reflect that, but at the price they go for today I can't think of much better for beginners and even beyond.
A couple of years ago I picked up a 300/500 Schneider Symmar for $200 at a camera show. I had always heard the convertibles were dogs but this appeared to be new, and I was thinking more of the Copal #3 shutter and what I could use it for.
At 300 the lens is pretty sharp and very good when stopped down. The 500mm seems to be a little bit soft. It works for some portrait situations and certain landscapes. It is big and heavy. Since then I have bought other standard lenses to cover that range and are small enough to be easily used on a smaller 4x5 lens board.
a couple of years ago I picked up a 300/500 Schneider Symmar for $200 at a camera show. I had always heard the convertibles were dogs but this appeared to be new, and I was thinking more of the Copal #3 shutter and what I could use it for.
At 300 the lens is pretty sharp and very good when stopped down. The 500mm seems to be a little bit soft. It works for some portrait situations and certain landscapes. It is big and heavy. Since then I have bought other standard lenses to cover that range and small enough to be easily used on a smaller 4x5 lens board.
i also have a symmar 210/370. i have shot it both as a 210 and a 370 ( portraits and architecture - color & black and white). it is true the lens it weighs a ton, but considering all the stuff i have to carry - it really doesn't matter too much . is sharp in the short focal length, and it has a nice softness to it when converted. mine has weird black specks inside the rear element ( separation?) so it might be softer than the usual lens ...
i really like it because it kills 2 birds with one stone, AND it covers a 5x7 negative without a problem.
I own a bunch of casket sets and a few convertibles.
Good casket sets: Goerz Pantar, Goerz Doppel Anastigmatlinse, Emil Busch Vademecum.
Not so good: Ralph Golshen 8x10 Convertible Set.
Really not so good convertibles: 8x10 and 11x14 Gundlach Rapid Rectilinear.
If I had to make a bang for the buck recommendation, I would say that the Busch Vademecum set is about the best thing going. It's sharp, surprisingly contrasty, very small and unbelievably light, but the drop in filter arrangement makes shutter mounting a problem.