Tele-converters

[woodrim]

I had intended to ask the folks here about tele-converters before making any purchase, but then saw two M42 2x tele-converters on ebay for $9.99 - one Vivitar and one Soligor. I put in the opening bid not expecting to get it, but no one else bid. That's not a good sign; I suppose I have just bought junk. So now the question: Which converters are worthwhile and don't kill lens performance? The one I had back in the 70's was pretty bad. I think I may now have two more of them.

[Anu]

[Rusty]

They do make very nice extension tubes if you knock the glass out

[westromat]

[Excalibur]

[luisalegria]

By reputation, the Kiron 7-element (also sold as a Vivitar) and the Komura Telemore are supposed to be some of the better ones.

On your lenses, practically speaking, who knows. Try what you have.

Practically, all are going to be at least a bit disappointing unless you stop down. That said, even the most unlikely ones can give very sharp results at a lens aperture of f/8 (effective f/16 on a 2X).

TC's are not in great demand now and huge numbers were made back in the day, so they can be had effectively for free in lots.

[Anu]

[martinsmith99]

I have a Vivitar 3x and it's not really useable. Ok for fun but not for serious shots.

[hinnerker]

[timo832000]

The results of the Leica t-con are very well, can you also post some crops of these images?

Timo

[woodrim]

My only reason for buying those TCs is for extending my 200mm. I see no advantage in doubling a short lens to accomplish only what one of my longer lenses would provide. I suspect these two are old dogs, but we'll see. My 200mm is sharp, but does suffer from purple, so this should be interesting.

As an aside, I had heard that the lens mount adapters, that include glass to correct for registration distance, degrade IQ. I'm sure that's true, but I'm actually quite surprised at how well they do. I had ordered a plain ring adapter from China to allow me use of some old lenses in macro mode, but they sent me the adapter with corrective glass. I can see issues at the edges, but the centers are pretty sharp.

[likealens]

The Leica R APO 1.4X and 2.0X are superb. The Leica R 2.0X (non APO) is a major step down but still better than any others that I have seen. Sometimes I think the APO extenders improve my IQ with non APO lenses.

[walter g]

Try your tele's on different lenes including some of the shorter ones.
You might find a combo you really like.
Depending on which Vivitar tele you bought, you might really like it.

I bought My Tele for my 80-200 one touch lens And I really like that combo.

I got a real good price on mine. It's a JC Penney 2x. with case NOS for 10 bucks.

It's identical to some Vivitars I've seen.

Walter

[Russ]

WhicH Vivitar is it? If it's the "macro-focusing" unit, it's a very good 7 elemend design. If not, it's nothing special. The Kiron MC-7 is very good too.




Kiron Kid

[woodrim]

I haven't received them yet, but here is the sale picture:


My guess is junk. No one else bid.

[Russ]

[westromat]

[Mike Deep]

[woodrim]

Pictures didn't look bad at all. Some Photoshop and all will be good. At a minimum, it'll be fun to test out. I'll report back with images.

[aoleg]

Vivitar 2x Macro Focusing Teleconverter (exact name from the unit itself) is no slouch either. It's one of the better TC's out there, has 7 elements, and is allegedly built by Kiron. Its optical performance is quite good for a doubler, and it also has a focusing helicoid, allowing lenses to focus closer. WIth a 50mm lens, it gives 1:1 macro.

[PaulC]

I got a Vivitar 2x in 2003 when I was starting out in digital. I tried it with the useless 75-300 (3.5-5.6) Canon lens and got such crap results that it went into a drawer and got forgotten. A few weeks ago I got it out and tried it with the Canon 70-200 f2.8L and was surprised to find the results were not bad at all, even on a 5D Mk2, so I wouldn't (any longer) dismiss all these cheap TCs as being worthless.

[spleenone]

I heard (or read) about formulas which told that with 1.4x conv you have to stop down one stop and for 2x it is two stop. On digital body with digital convertors it said that is will automatically compensate with TTL metering. It is about that for better IQ degraded with conv glass is better to stop down doesn't it? How it really works?

[PaulC]

You don't stop down. What happens is that the teleconverter reduces the amount of light reaching the camera, so my f2.8 lens with a 2x converter on will only allow as much light through as if it was an f5.6 lens.

In modern SLR cameras, the meter reads the incoming light so it should give you the right reading, anyway.

If you are calculating the aperture using a separate, external light meter then you would need to make an adjustment for the lost light but not many people do that nowadays.

[alex]

In my impoverished youth I had a couple of tele-converters of modest cost, and they put me off tele-converters. These days, I use Zeiss Mutars, and they confirm that old adage about getting what you pay for.

[spleenone]

@ PaulC: Now it's clear to me. Giving a sense. Thanks.