# 2x 3x lenses?



## jamesdavidboro (Nov 8, 2010)

Are they any good? Obviously there must be a downside but what is it? Do you lose any sharpness or is it just that you lose some Aperture?


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## Bend The Light (Nov 8, 2010)

jamesdavidboro said:


> Are they any good? Obviously there must be a downside but what is it? Do you lose any sharpness or is it just that you lose some Aperture?


 
You can lose both, sharpness and aperture.
The addition of extra glass is going to block some light, and the glass quality will always affect image quality. Whether it's noticable depends on the quality of the glass, and whether you stack them.

Just for a laugh, I stacked 3 lots of 2x and one 3x comverter on my 300mm lens, effectively a 7200mm lens. Great magnification, but crap image!


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## Ron Evers (Nov 8, 2010)

You would be better off getting a set of extension tubes, you will lose light but not IQ.


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## Dao (Nov 8, 2010)

From what I read, technically image quality can be affected by extension tubes as well.  When lens is designed and calculated to perform the best at a particular settings including the distance from the last lens element to the film/sensor, with the extension tube, it is not the same anymore.  As a result, image maybe affected.

Also, extension is not the same as teleconverter (TC). 

As far as sharpest goes, I believe the answer is yes.  TCs affect image quality. Also, if a lens has optical flaw such as CA, TC will magnify that flaw as well.


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## Ron Evers (Nov 8, 2010)

I assumed OP was speaking of close-up filters since I am not aware of 3x tele-converters. 

There may be some minor loss of IQ with tubes but nowhere near as bad as the close-up filters.


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## DerekSalem (Nov 8, 2010)

Well I've only ever seen 1.4X and 2X tele-converters...but the higher you go the more light you lose and the more IQ you lose. Most people recommend getting the 1.4X since it only makes you lose 1 stop of light and doesn't degrade image quality too much. The only people that should be getting 2X converters are people that have f/2.8 or faster glass (and only some are compatible) and glass that's *very* sharp to begin with...since you'll lose quite a bit of image sharpness.


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## Dao (Nov 8, 2010)

Ron Evers said:


> I assumed OP was speaking of close-up filters since I am not aware of 3x tele-converters.
> 
> There may be some minor loss of IQ with tubes but nowhere near as bad as the close-up filters.




Hum ....   I thought OP was talking about TC.   I guess we need him/her to tell us more.   And yes, there are 3x TC out there but 1.4 and 2x are more popular.

As for the close-up filters, I read that some of them are great optically such as the Canon 500D as well as the one (Raynox) you have.


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## Bend The Light (Nov 8, 2010)

Well, there are 3x teleconverters. I have one. I have  handful of 2x as well. They're for my old M42 lenses...

As for new ones, with AF etc., I don't know.

Cheers


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## Dao (Nov 8, 2010)

Kenko make one call "Kenko Teleplus PRO 300 "DG" AF 3x Teleconverter"


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## jamesdavidboro (Nov 8, 2010)

Yes it was Tele converters that i was refering too. It will be for my M42 lenses that i've just bought. Mainly for a Paragon 135mm f/3.5 but i've also just bought a Helios 58mm f/2.0. I'm looking at a Vivitar 2x at the moment. How many f stops would i lose with that?


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## Ron Evers (Nov 8, 2010)

jamesdavidboro said:


> Yes it was Tele converters that i was refering too. It will be for my M42 lenses that i've just bought. Mainly for a Paragon 135mm f/3.5 but i've also just bought a Helios 58mm f/2.0. I'm looking at a Vivitar 2x at the moment. How many f stops would i lose with that?



Two stops I believe.  

I have the Helios 44-2 58/2 & it is a great lens.  You just have to get used to the preset feature.  I leave my aperture set @f11 & then adjust the stop-down ring to get the desired DoF without knowing exactly what f stop it is.


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## Ron Evers (Nov 8, 2010)

Dao said:


> As for the close-up filters, I read that some of them are great optically such as the Canon 500D as well as the one (Raynox) you have.



The Canon & Raynox are very different critters from the close-up filters that come in sets with something like a 1x,2x & 4x.


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## Bend The Light (Nov 8, 2010)

Ron Evers said:


> Dao said:
> 
> 
> > As for the close-up filters, I read that some of them are great optically such as the Canon 500D as well as the one (Raynox) you have.
> ...



For close up I use my canon fitting macro tubes with my 135mm M42 lens (f2.8)...it's a nice combo on my 400d. I just sold a Helios 44M-2 58mm on eBay, and a 135mm Helios. They were nice lenses, but I already had the focal lengths covered.

The close up lenses, 1x, 2x, 4x, 10x, are ok, but introduce a lot of distortion and CA. I stopped using mine. Apparently, like you say, Raynox are much better, but obviously not so cheap!


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