Lens converter 2x

Does anyone use them and if so how does it effect the quality of the photo,using say a 1.4 50mm prime.

I use one for wildlife shots with my Sigma 135-400mm lens its gives you roughly 2 stops less light and it can make your shots a little soft so if you can manage without one its better. David

If you must use a TC then a 50mm lens will at least give you the best of things. Quality will suffer, but on the other hand it will effectively create a 100mm f2.8 Macro Lens which could be very useful.

Yes that was along the lines I was thinking John with the Tamron 2.8 90mm being around 300 pounds and the 50mm at 150 pounnds that seems a nifty way of saving a bob or two if it works well. As well as increasing the focal length on the rest of my kit should it be needed.
Ian

But surely it will only usefully increase the focal length of your longest lens? If you have a 50 then doubling say a 10-20 is pointless and I'd have thought that the loss of quality would mean you probably can't use the TC & 50 at maximum aperture.

I'd rather try and find a quality S/H lens of the focal length you want to double to than use a TC - but each to his and her own I guess.

Mike

That's all very well, but a quality lens of 300mm or so doesn't come cheap.

G

True enough but will a TC plus a 135/150 be 'quality'? Perhaps I'm living in the past when TC were really not that good. I'm a bit baffled by the idea you buy a lovely 50mm 1.4 and then stick a TC on it. Your 300 argument I can understand better.

Mike

I have a couple of Pentax T/Cs, and use them (often together) on my longest lens - an M 400mm. The results are OK, and better, I think, than enlarging the image from the 400mm alone. The price is also much less than a 1200mm lens.

But as you suggest, for more affordable focal lengths I would much rather buy the appropriate lens than use a T/C.

G

Hi Mike my reason for using a tc on a 50mm would be for around the dog shows that I attend from the ring side the extra focal length will come in very useful if the quality is up to scratch. I have never realy used a tc except for some years ago when I used one with an olympus om1 I had at the time obviously things have improved since then hence the question.Taking into consideration one of the nearest lenses is 300 pounds or more then it just might save me a bob or two as stated if it works.
Ian

Quote:
Posted 15/08/2008 - 23:05
If you must use a TC then a 50mm lens will at least give you the best of things. Quality will suffer, but on the other hand it will effectively create a 100mm f2.8 Macro Lens which could be very useful. Best regards,

John Riley

Unquote


Sure it will effectively create a 100mm f2.8 lens, but why would it become a macro with a standard doubler? Wouldn't you would need one of those Kenko 2x macro focusing TC's or similar to create macro properties.

Because the closest focusing point does not change. A 100mm lens focusing to the minimum distance of a 50mm has approximately 1:2 magnification, which is the same as many macro lenses of the manual focus era at least.

Surely if that were the case there would be no need for 2X macro converters, everyone would use a normal teleconverter.
And Macro teleconverters would have no need for the macro side, they would just be a basic teleconverter.

Wouldn't they ?

With my 2x macro teleconverter I turn it one way for normal focus (2x teleconverter) and the other way for macro capability.

I'm confused now.

2x Macro Converters have additional focusing ability built into the TC. I'm not sure if this means that they could focus to 1:1 as a result, but I have a feeling that might have been the reason for their existence.

Proper macro lenses used to focus to 1:2 only, modern ones tend to focus all the way to 1:1

The macro lens is the best option in terms of quality. Its only disadvantages are cost and bulk.

Ah, missed the 1:2 focus bit.
So you are saying that if I put my 2x teleconverter on my Pentax A-50mm or F-50mm 1.7 it should give the same focus ability as my M series 50mm f4 1:2 macro lens?

Edit : On second thoughts that would that be the same as a 100mm f4 1:2 macro lens

Your second thought is spot on.