TELECONVERTER? Which, When, Where, and Why?

[spyglass]

TELECONVERTER? Which, When, Where, and Why?

Thought it would be interesting to gather opinions on Teleconverters so I created a little poll and a thread to invite ideas and experiences on the subject.
I still have my first Teleconverter. It was made by Soligor. It was referred to as a doubler. It also serves as an extension tube, as its design allows the lens (guts) to be removed making it a simple tube. I remember when I first got it and showed my photography teacher. He raised an eyebrow and said “oh you got one of those…. you will lose 2 stops with that thing, and increased magnification comes at the cost of quality”. Oh course this is not what I wanted to hear. So much for show and tell.     Unfortunately for me he was right. His prediction in that single verbal exchange summed up my relationship with Teleconverters. Like every dark cloud there was a silver lining. I had discovered extension tubes and a whole new world, a world of infinite detail and possibilities. I found the door to the Macro world.
Over the years I have viewed some excellent images from some remarkable photographers. Some have used Teleconverters. Obviously you get what you pay for and one should not close the book on Teleconverter based on an experience with an inexpensive product. I have been tempted lately to pick up one of the Pentax Teleconverter to re explore the issue. Perhaps we could get some replies and create a knowledge base on Teleconverters. Please feel free to answer any of the suggested questions below or provide any thoughts, questions, or answers that you might have on the subject

1)  Which ones (make & model) do you feel best serves a Pentaxian
2)  When (do they work best, on what lenses)
3)  Where (for what area of photography, on what type of lenses)
4)  Why (necessity, flexibility, or luxury)


Thanks Everyone,

Spyglass

[Mike Pearson]

I would like a Pentax 1.7 Auto. A friend has one and it is awesome.  Oo)

Mike

[tcom]

I have a Pentax F 1.7x AF converter.

It is a 1.7x teleconverter with a moving lens. The lens does not move much, but it allows to add limited AF to non AF lenses. When using it on a MF lens, I do a coarse focus by hand and let the camera do the fine focusing with this converter.

I tried this 1.7x AF converter on several lenses without a lot of success. A teleconverter does reduce the optical quality of a lens especially in contrast and sharpness. On a consumer lens, this reduction is too important to be really usable.

But on exceptional lenses, the impact of the teleconverter is not really noticeable.

I mostly use this teleconverter on the Voigtlander 125/2.5 macro lens. The main reason is to add AF to the lens, mainly to gain on speed when photographing insects. The longer working distance to get the same result as without TC is also very handy, especially on insects.

[jazz28]

I have a Vivitar 2x macro focus. It's designed for a 50mm lens and works quite nicely in macro but not so great at x2, but acceptable. I don't use it much now, I have a set of extension rings and 500mm mirror lens.

[LaRee]

I am ashamed to admit that I own both the Pentax 1.7 af tc and the Vivitar 2x macro tc and haven't used them near like I had planned to at first. I love the pentax 1.7 af for long mf lenses though. But I really need to put it on the Voigtlander 125/2.5 macro lens. I know that will be a good combination. Thank you Dominique for the inspiration to give this combo a go. So many options, so little time.

[tcom]

Thank you LaRee. This forum is here to share the inspiration. The Voigtlander 125/2.5 with the 1.7x AF converter is really a great combo.

[Adnan EROL]

I have VL 125 and Pentax 2x-S rear converter. They are both so good that I stopped looking for DA*200mm and 300mm now.

One day when I have a FF DSLR, I hope then it would be with "interchangeable sensor" so that I'll change to cropped sensor for 1.5x teleconverter effect.
(select the CCD sensor to get sharper images, change to CMOS in need for extra high ISO, and foveon sensor for brilliant colors and so on...)

[JIMBO]

I recently purchased a 2x for my sigma 70-200 and have not been overly please. Extremely difficult to focus and forget even trying without a good tri-pod and cable release. Should have gone for the 1.4 which I hear is a better option. I will continue to try to work with it but may sell it down the road. JIMBO

[francis lee]

Uh... Hi people, not sure if this will be of interest to anyone.

Moons ago, I unscrewed & removed the glass elements (stained with fungus) of my very first bought (1982) 2x tele-converter. Without the glass inside the converter, it is now playing the role of a very hard-working extension tube for my standard & macro lens. Sometimes, I even used it on my 200/300mm lenses as it reduces the minimum focusing distance, thus allowing me to focus on closer elements yet giving a 'compression' effect of the tele.

Since its 'glass-less', there isn't any light-loss or fall off with image quality.

You can actually purchase a used or spoilt tele-converter for this 'recycle' purpose. But do remember to get one that allows you to keep the exposure reading & even Auto focus too when coupled up with your Main lens & body.

[LaRee]

Uh... Hi people, not sure if this will be of interest to anyone.

Moons ago, I unscrewed & removed the glass elements (stained with fungus) of my very first bought (1982) 2x tele-converter. Without the glass inside the converter, it is now playing the role of a very hard-working extension tube for my standard & macro lens. Sometimes, I even used it on my 200/300mm lenses as it reduces the minimum focusing distance, thus allowing me to focus on closer elements yet giving a 'compression' effect of the tele.

Since its 'glass-less', there isn't any light-loss or fall off with image quality.

You can actually purchase a used or spoilt tele-converter for this 'recycle' purpose. But do remember to get one that allows you to keep the exposure reading & even Auto focus too when coupled up with your Main lens & body.

I've heard of this suggestion and had it in mind when I unexpectedly won this on ebay:
http://cgi.ebay.com/ws/eB...tem&item=370118721595
I am certain it is junk, but hollowed out it could work as you share here right? The hard sided case the thing came in is almost worth the price of the tc. ;-)

[francis lee]

I've heard of this suggestion and had it in mind when I unexpectedly won this on ebay:
http://cgi.ebay.com/ws/eB...tem&item=370118721595
I am certain it is junk, but hollowed out it could work as you share here right? The hard sided case the thing came in is almost worth the price of the tc. ;-)

Ya, I'm sure it will work as the seller proclaim on the Pentax bodies BUT the problem is that you may not be able to maximise full usage with the newer cameras. The Z series & the entire range of Digital ones cos' the teleconveter is designed for the older K series cams.

There's no metering read-out, no auto-focus. Only Cte-weighted metering mode & you will have to use a light meter for setting the approx EV.

Its back to basic man... but nevertheless... have fun!

[pentaxer]

Answer to spyglass questions :

1)  Vivitar 2X, IMO.
2)  They work best when using my manual focus prime lenses, eg. SMC 50mm 1.4
3)  Macro on insects, plants, birding.
4)  Why? - Coz of flexibility

[terrytootall]

Hello

I have an ASAHI TAKUMAR-A 2X tele-converter, with 6 electrical contacts. It came with my *ist-DL (and 18-55 and Sigma 28-300). I took some interesting shots with my *ist-DL, especially using the 28-300!! To date, I have not used it with my K20D. Possibly in the warmer months.

TerryTooTall

[Craig]

Terry,   I'd really like to see your results with that 2x T.C.

[roentarre]

Thank you LaRee. This forum is here to share the inspiration. The Voigtlander 125/2.5 with the 1.7x AF converter is really a great combo.

Interesting combination that I never thought of!  I would try that on the weekend!