Dedicated telelens versus 2x teleconverter

[dnjl]

Being a 'normal' shooter, I very rarely feel the need for anything longer than 85mm. For the few occasions where a tele might be needed, I was wondering about the benefits of a dedicated telelens over a 2x teleconverter. Is it worth adding a (large!) extra lens to your bag, or will a teleconverter (in my case, the FD 2x-B) work just fine on, say, a FD 50mm f/1.4 or a FD 85mm f/1.2 or perhaps a 135mm f/2.8? What are the benefits/problems? I know that you lose some light, but if you start with a large aperture, that's still okay to work with. I guess that depth of field decreases as you add a converter, but I could live with that too. What I worry about most is the optical quality.

Thanks for any opinions on this.

PS: I need infinity focusing abilities, so a simple extension tube won't do.

 

[holmburgers]

I would recommend buying a 135mm or something. Teleconverters will always be less than perfect in terms of optics. Any purist will say get a dedicated lens. Then again, depending on your requirements, you might be happy with it. You could probably find one and test it for dirt cheap and then make your decision.

An extension tube doesn't change the focal length, it just allows for closer focusing.

 

[Christopher Walrath]

Not familiar with the FD telecons, but as a general rule of thumb, there is some light fall off, perhaps some lessening of sharpness. As you stated, you add less wieght to the bag and come away with a 100mm, a 160mm and a 270mm with your examples. Maybe that was 170mm. You know the pros and cons already, so it seems.

 

[Ian Grant]

I've had 3 or 4 teleconverters over the years and would recommend even a cheap telephoto lens in preference, it's hard to make a poor telephoto lens or at least one that won't outperform a normal lens + converter.

You can get some great Tamron SP lenses very cheaply and the Canon FD Adaptall mount, that's what I've done for my Pentax's (but with Pentax Screw & K mount Adaptall mounts), I can also use them manually on my EOS cameras.

Ian

 

[Christopher Walrath]

I agree. I have a 2x for the Minoltas but seldom use it. I have a different focal length lens whenever possible for coverage.

 

[Ian Grant]

There was always a 2x Telemore converter in my 35mm camera flight case from the mid 70's until sometime in the 90's, apart from testing it out I never found a need to use it. I still have it I think, not sure if it's my original or a replacement bought later after cameras were stolen but these days the 35mm gear is rarely if ever used, except for a vintage Exacta

Ian

 

[dnjl]

Thanks everyone. It appears that the consensus is leaning heavily towards using a dedicated telelens. Meanwhile, I dug up an interesting discussion on the subject:

http://photo.net/canon-fd-camera-forum/008ve5

As it appears, a teleconverter uses only half the image coming through the lens and magnifies it to full frame. Obviously, this leads to degraded image quality.

I guess that answers my question. At the current bargain prices, I think I'll just buy a real telelens.

 

[Galah]

I use a number of "veteran" M42 film bodies and lenses. Much to my surprise (in view of the conventional wisdom, as exemplified by posts in this thread) both of two, cheap, "no name" 2x TCs (picked up in junkshops for around Aus$5-00 to $10-00) have performed more than acceptably well with my M42 lenses in the 50 to 135mm range.

I now have a new respect for these things and generally carry one in my bag as a matter of course.

 

[MattKing]

I have and use a Vivitar tele-converter that also gives me close-focus abilities. It does degrade the image when used at longer distances, when compared to a fixed focal length telephoto lens, but the combination of its small size and excellent utility means that it stays in my bag.

Here is a link to a review of the version in newer, Pentax mount:

http://www.pentaxforums.com/userreviews/Vivitar-2X-Macro-Focusing-Teleconvertor-for-Pentax.html

The version I have is probably considerably older than the one reviewed.

It would be interesting to compare the optical quality of the converter I have (when paired with one or more of my Zuiko fixed focal length lenses) with the Sigma close focusing 70-200mm zoom lens I have in OM mount

 

[Galah]

Matt's post reminds me of the truly excellent Teleplus MC7 2x Macro teleconverter I have in Pentax K-mount which gives me up to 1:1 magnification as well as 2x TC capacity and is absolutely brilliant with my Pentax-M 1.7/50 normal lens (as good as some of my dedicated Macro lenses) giving infinity focus and converting my 50mm lens into a great (100mm + Macro) walkabout lens.

Really great!

See here: (there was a url link here which no longer exists)

 

[2F/2F]

With the low cost of most film equipment these days, I really don't see a ton of point in compromising, unless you are really strapped for space. I have a few, as they tend to come ones way for free or cheap. I have only used one of them, and only a handful of times.

I have used the newer Canon EF 1.4x because new AF super-long lenses are not common among my friends, and it got the job done OK. I have used it on the 70-200 f/4L lens, and also on the 2.8. Pix were sharp enough for a newspaper wide open or a stop down. But if I wanted something as sharp as I could get it so I could make a really nice print on photo paper, I wouldn't use one myself.

 

[darinwc]

I have a tamron Sp 70-210mm lens with a canon FD mount that is about as compact as my 85mm f1.8.. and about half the weight.

 

[Excalibur2]

A 2Xs extender is useful for sunny days without a tripod (2 stops loss) as it can turn a zoom @210 into a 420mm lens (erm a Tamron sp 60-300mm would give 600mm).......
I have accumulated about 5 extenders over the years and some zooms and primes work better with extenders, also some combos work better than others and so there is "mix and match" too e.g. this 2Xs Vivitar extender is made for the Vivitar 70-150 zoom, but gave good results on a Tamron 70-210 zoom.
So if you use a VG prime or Zoom and match with a VG extender, you'd be less disappointed with the loss in sharpness.

Tamron 46a @ 210mm

Tamron 46a @210=420mm with Vivitar 2Xs extender

 

[narsuitus]

Years ago when my longest focal length was a Nikon 200mm, I used a 2x teleconverter for the rare occasions when I needed 400mm.

Years latter when I started using the longer focal length more and I needed better image quality; I purchased a Nikon 1000mm lens and use a 2x on it for the rare occasions when I need 2000mm.

 

[darinwc]

Well, to answer your question..

There are good teleconverters out there. Name brand Nikon/canon etc converters are often designed for a certain focal length or even for a particular lens.

Other brands will have variable quality, but I remember hearing that the kenko 7-element tc was good.. maybe someone with experience will pipe up. All teleconverters will reduce the amount of light reaching the camera. 1.4x will reduce the lens effective maximum aperture by 1 stop and 2x by 2 stops. I'm not sure about 3x. All teleconverters will reduce the image quality by some amount but some are really bad (ive had these) and some are acceptable.

Now, teleconverters are usually used on a long lens to get an even longer focal legth. But it sounds like you are more interested in using it on a normal or short tele. In my opinion a 100mm f2.8 would be better than a 50mm +TC. But if you have a 85mm lens, it may be worth it to use a TC cause you can slip it on your pocket. Even though a 135mm or even a 200mm can be compact, it would be considerably larger than a TC.

But consider this.. If you are using an 85mm and really need to get closer, just take a few steps closer or take the shot and crop afterwards. it will be much better than fiddling with a 2nd lens or TC.