Using a teleconverter as opposed to buying the lens

[IronMaskDuval]

What are the downsides of using a teleconverter instead of buying a lens in the focal range that I want? I have a Contax 50mm 1.4 that I really love, and I'd like to buy a Contax portrait lens, but a fast one is more than I want to spend, but the teleconverter is only about $60. So, will I be able to produce just as good portraits with a teleconverter, or should I go ahead and buy a dedicated portrait lens?

 

[DarkShadow]

Well here is my take on this though I don't do portrait work.I exclusively use my Nikon AF-S 300mm f/4 for birding and I have a 1.4 TC for that extra reach and what I noticed with and with out it. with out it, better IQ and sharper and spot on focus and seems to focus faster. With the TC the obvious 1 stop lose of light slight drop in IQ and sharpness, slower focus and back focusing but that some what easy to resolve with AF fine tune.I no longer use it because I want my lens to be at its best and for a $1300.00 piece of glass why rob it from its goodness even if its minimal.YMMV.

 

[jaomul]

I'll never buy a teleconverter again. I'd crop to get the shot from the shorter lens or try get the correct lens.

I understand this may not be ideal with a 50mm and probably not an option with film

 

[Overread]

A few thoughts:

1) Most teleconverters are designed for long focal length lenses, typically those over 200mm in focal length. This is important to consider because most of those longer lenses often have a gap at the back of the lens, so the rear element isn't flush with the base of the lens. This leaves a slot which a teleconveter fits into with the front element, which often protrudes.
This means that, at a physical level, many lenses cannot be fitted to teleconverters. Kenko Pro teleconverters have about the flattest front, though I think there is still a modest rise.

2) A teleconverter will take away 1 stop of light in aperture; it will take away some image quality and it will slow AF. However it will also provide a greater resolution and detail than cropping and enlarging will typically produce. So a teleconverter is better than cropping, in most situations.

A 1.4tC has the least amount of loss and in many cases the image degradation is not noticeable in edited photos for display.

a 2*TC however has the greatest amount of loss and the image quality drop is noticeable. As a result this kind of teleconverter typically only gets used on top end lenses such as 300mm f2.8.

3) Price - a $60 teleconverter doesn't sound like its a high end or good quality teleconverter. Granted it could be a legacy lens (ergo still good quality but just a lot older); but in general most teleconverters of worth are typically a lot more in cost.
A low end teleconverter is, of course, going to have even more impact to the overall image quality so you might find that degradation too great for you uses.



Personally I'd advise waiting and saving up for a longer focal length lens that will do what you want without compromise.

 

[IronMaskDuval]

K, I bought a 100mm lens. Thanks, everyone.

 

[Derrel]

It always pays to TRY the teleconverter and the lens in question, to see how the pairing actually performs, for you, using your working methods. Portraiture does not always demand an ultra-high quality from the lens, and at f/4.5 or so, the 50mm + TC unit ought to deliver a decent image, or better than decent.

 

[KmH]

A bit late to the thread but a 2x TC costs the user 2 stops of light.
A 50 mm f/1.4 set wide open functions as if the aperture were actually f/2.8.
Set to f/2.8 the aperture functions as if the aperture were actually f/5.6, and so forth as the lens aperture is stopped down.

 

[IronMaskDuval]

Thanks, everyone. I ended up receiving my Tokina 100mm 2.8. This thing is awesome.

 

[DarkShadow]

Congrats on the new toy. I hear Tokina makes some really good glass. I actually thought about the mostly high regarded 11-16 for the wider angle indoor stuff.

 

[beagle100]

Thanks, everyone. I ended up receiving my Tokina 100mm 2.8. This thing is awesome.

better than using a tele-converter .... awesome !
www.flickr.com/photos/mmirrorless

 

[IronMaskDuval]

Congrats on the new toy. I hear Tokina makes some really good glass. I actually thought about the mostly high regarded 11-16 for the wider angle indoor stuff.

This thing is built like a tank. I bought a Nikon 100mm 2.8 e the other day that I took apart to clean the fungus, but I wanted the dual purpose lens, because we own a microgreens business and the macro function will be great for web product photos.

Thanks, everyone. I ended up receiving my Tokina 100mm 2.8. This thing is awesome.

better than using a tele-converter .... awesome !
www.flickr.com/photos/mmirrorless

Heckin yea! Just as cheap times six. lol