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Old Sep 3, 2006, 9:13 PM   #1
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Hi,

I'm interested in one of these asa cheap way to extend focal range on a Sigma 100-300mm lens I've just bought.

For Pentax thechoice I have seen on ebayis betweenSigma, Kenko or Tamron.Sigma only supports Sigma lenses while Kenko supports other brands which may be useful in the long run.

I understand that with a 1.4x you lose 1 F stop and with a 2x you lose 2 f stops. I believeAF is only supported to a limit of F5.6 soa 1.4x requires an F4 lens and a 2x requires aF2.8 lens toAF consistently.

Not sure about impact on picture quality or anything else?

Does anyone have one of these and able to share experience?

Thanks,

Bob




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Old Sep 4, 2006, 4:20 AM   #2
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Hi, I've just ordered myself a sigma 2x to go with my 70-300 so can let you know once I've tested it what it's like, not sure how long it will be before it arrives.

I am on a number of forums and have also looked at thousands of photos on pbase and some have been taken using 2x converters, be it sigma, kenko or other make and provided it's a reasonable photographer using them, I have seen some outstanding results. If it's people who are using a dslr for a point and shoot and they don't have a steady hand or aren't paying attention to focusing, then the results have been pretty poor but the more advanced amateurs and the professionals can produce such stunning shots.

Not sure how soon you want yours but if you can hold on until I've got mine and had a chance to test it and post some images and my initial views on how easy it is using it etc etc, then that's what I would advise for now.

It has been said that a 1.4 would be better as you don't lose so much light which is probably very true, depends on how patient you are in learning how to get the best out of a lens/converter I guess. I'm not the most patient person in the world so it will be very interesting to say the least to see how I get on with mine. Hehehe.

Hope this has helped.

Alison
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Old Sep 4, 2006, 4:32 AM   #3
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I also have a 2x teleconverter on its way. Hope it gets here by the full moon! I will let you know how it turns out. The one thats coming to me is a Pheonix 2x AF. I am going to use it on my sigma 100-300 "compact" lens. My plan is to use it for my kids soccer(er, football) games if needed.

Jon
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Old Sep 4, 2006, 8:14 AM   #4
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jabilson007 wrote:
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The one thats coming to me is a Pheonix 2x AF. I am going to use it on my sigma 100-300 "compact" lens. My plan is to use it for my kids soccer(er, football) games if needed.

Jon
Can't wait to see some shots from it, will be interesting to see how the phoenix compares with the sigma.

Can you also go buy yourself a long phoenix lens please and post some shots so that I can see the quality in order to decide whether or not to get one if I have enough money left over, hehehe. They are so much cheaper to buy than the sigma, tamron and such.

Alison
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Old Sep 4, 2006, 9:02 AM   #5
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I have a Kax Teleplus Macro 2x A series tc. Tried it with the DA 50-200 and it works very well as a macro tc and is not bad as a general tc as it is a MC& (multi coated 7 element)

I have the Tamron AF 1.4 tc coming this week. Many people i have spoken to say the AF works very well at apertures smaller than F4 despite what the instructions say.
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Old Sep 5, 2006, 1:13 PM   #6
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alibunnylady wrote:
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Can you also go buy yourself a long phoenix lens please and post some shots so that I can see the quality in order to decide whether or not to get one if I have enough money left over, hehehe. They are so much cheaper to buy than the sigma, tamron and such.

Alison
Alison
I have one of these, just bought it at a local pawn shop. The brand on mine is Five Star but it appears to be exactly the same as the Phoenix/Opteka/"Your Name Here" 500 f8 long lenses on ebay. It is quite light and obviously of lower quality build but for the price I thought it would be a cheap toy to experiment with. I will try to get some shots for you to view. They will be handheld, no tripod here yet.

Tim
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