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04-01-2007, 11:33 AM   #1
Aneopa
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Rear Converter-A 2X-S

Hi

I want to use a 2x converter in Pentax M 200mm f/4.

I known this will step down a stop or two, making a 400mm f/8, but my favorite photography places are in the Brazilian outbacks, normally reached after a really long walk under a tropical sun and in a hard terrain. In these conditions any extra weight has to be avoided, so if I need a tele lens I'll choose a more light option (and cheap too) than a weighty one, even though this make my photos not so good.

My question is, can I use the Converter-A 2X-S (A 2X-S) with a 200mm lens?

I know the S in 2X-S means short, in opposite of the L in 2X-L meaning long. The 2X-L is indicate to 300mm lens and over, so may i deduce the 2X-S qre indicate for shorter lens like Pentax M 200m f/4?

Has anyone already tried that?

Thanks in advance

04-01-2007, 01:29 PM   #2
roy
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i use a tamron on mine and also the 1.4x-s. it works just fine. no examples but if you give me a little time i'll go shoot some.
04-01-2007, 02:20 PM   #3
Aneopa
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QuoteOriginally posted by roy Quote
i use a tamron on mine and also the 1.4x-s. it works just fine. no examples but if you give me a little time i'll go shoot some.
Thank you Roy. This would be great

Last edited by Aneopa; 04-04-2007 at 05:27 PM.
04-01-2007, 02:43 PM   #4
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here's a quick test i posted with the M200 + 2x tamron. these are full size shots taken at f8 with flash. they are all around 1meg. i think it's a good match. the 2x-s should produce better than this.
200

04-01-2007, 03:44 PM   #5
Aneopa
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Tnak you very much Roy!!! You have helped a lot, I'll get the 200 mm lens now and next month take the rear converter. As soon I get will post here some photos.

Thank you again.
04-01-2007, 04:22 PM   #6
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after this you should consider a 300mm f4 and the 1.4x-s. that will give you a 420mm f5.6. this is still handholdable(barely) and really gets you a nice birding lens. the 2x on a 300mm is almost impossible to HH.
04-01-2007, 07:40 PM   #7
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I used 2S tele on A*300 f2.8 giving little image degradation. This teleconverter is really great!

1/90s f/5.6 at 600.0mm iso1600 full exif (Wide open after telex2)



1/90s f/8.0 at 600.0mm iso400 full exif



1/250s f/7 iso1600 full exif





I trust this teleconverter a lot (But you would need a good quality lens to have a great image wide open to start with)
04-01-2007, 08:02 PM   #8
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QuoteOriginally posted by Aneopa Quote
I want to use a 2x converter in Pentax M 200mm f/4.

My question is, can I use the Converter-A 2X-S with a 200mm lens?

I know the S in 2X-S means short, in opposite of the L in 2X-L meaning long. The 2X-L is indicate to 300mm lens and over, so may i deduce the 2X-S qre indicate for shorter lens like Pentax M 200m f/4?
Not exactly. The "L" converters are dedicated converters intended to be used with specific long lenses. If the lens is not on the list of compatible lenses, then the converter probably won't even fit on the lens (due to the protruding front element on the converter). An L converter with a matched A* or F* lens will give outstanding results.

The "S" converters are general purpose rather than dedicated converters and they will fit most of the lenses in the Pentax line. They won't give results as good as a * lens with an L converter, but they can give decent results.

I haven't tried the specific combination that you are considering but the combination will operate and function properly. You will have to test the combination to determine whether you find the results satisfactory.

One final note: 1.4X converters result in less loss of quality than 2X converters. If 280mm is enough reach for you, I'd suggest the Pentax Rear Converter A 1.4X-S or one of the better third party alternatives.

04-01-2007, 08:06 PM   #9
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I have a PK T6-2X which has seen quite a bit of use over the years. I can't post any samples, but be assured that, in combination with a PK-A 70~210 f4 it it's done a great job, and even more so with a PK-M 300.
Alas the latter is now under several fathoms of (pardon the reference ) NaCl.H2O in the Southern Ocean as a consequence of a minor, if expensive, boating incident.
And no; it was another boat, not a whale.
04-02-2007, 05:54 AM   #10
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i'll second rolly. the 1.4x-s does real good on the 200mm and the 300mm. practically no IQ loss. and as adam has shown it also works great on the 500mm. if you haven't got the 200mm yet i'd suggest a 300mm and a 1.4x-s. this is more in line as a birding combination.

rolly, you should have had your lifeline on.
04-04-2007, 06:00 PM   #11
Aneopa
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Thank you all for the answers. At moment IŽll keep the M 200mm and later I try to take a 300mm.

Your advices, specially yours GaryML, changes my mind about the 2X-S, I realize the 1.4 X is a better company to the 200mm than the 2X-S, but now I'm having a hard time trying to find a Pentax 1.4X. I have found a Tamron 1.4X ( Photo Division, Tamron USA ) , Do you have any thoughts about this converter? Anyone has already use it?

roentarre what great pictures!!! Unluckily a *300 is over my budget at moment.

Rolly I"ll keep a eye when I go a beach here in Brazil, if the stream bring me anything IŽll let you know

roy Your help was inestimable as always.

One more time, Thank you all
04-04-2007, 08:43 PM   #12
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QuoteOriginally posted by Aneopa Quote
Your advices, specially yours GaryML, changes my mind about the 2X-S, I realize the 1.4 X is a better company to the 200mm than the 2X-S, but now I'm having a hard time trying to find a Pentax 1.4X. I have found a Tamron 1.4X ( Photo Division, Tamron USA ) , Do you have any thoughts about this converter? Anyone has already use it?
I'm glad my comments were helpful.

I have used the Tamron 1.4X converter. It is reasonably priced, readily available and gives good results. A lot of people are happy with it. The image quality of the Pentax 1.4X-S is slightly better (especially at wider apertures) and the Pentax has better build quality with a metal body instead of plastic. But the Pentax is not available new and used copies are very hard to find.

My main complaint with the Tamron was the fact that it had an auto-focus connection. With the lens I wanted to use it with (a Pentax FA 135mm f2.8 IF) the auto-focus performance was terrible with the converter, and even with manual focus the converter AF coupling created so much drag that manual focus was inconvenient. With a manual focus lens, or with a lens where the manual focus decouples the AF screw (like DA lenses), there is no problem.
04-05-2007, 03:08 AM   #13
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forgot to say, i've found that my A1.4x-s does not close down the lens's aperture when using a manual lens unless i use a piece of tape to block the contacts of the converter. any one else have this problem?
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