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11-22-2011, 06:44 AM   #1
Finknottle
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2X Teleconverters for K-r.

I have been offered a 2X teleconverter for my new K-r. Are they are force for good or evil? What precisely do they do? Kind regards.

11-22-2011, 07:24 AM   #2
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Teleconverters are typically primarily used in conjunction with faster high end lenses. A 2x teleconverter takes away 2 stops of light - if you put that on one of the telephoto kit lenses (50-200mm or 55-300mm), at the telephoto end you'll be shooting at F11 wide-open - the viewfinder will be very dim due to not much light getting through, and there is a better chance than not that autofocus will not function, except in the brightest outdoor conditions.

If it a good deal and you have or intend to buy some fast F2.8 telephoto lenses then it would be worth it.
11-22-2011, 08:25 AM   #3
Finknottle
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Thanks for the information, pxpaulx, it is greatly appreciated. As I am only a 'duffer' I shall pass on the offer.
11-22-2011, 12:47 PM   #4
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Decision algorithm:

IF the TC is A-type, with aperture-control contacts on the mounts
AND the TC is pretty cheap, like under US$20 shipped
AND you are interested in macro and close-up work
THEN the TC is worth buying and de-glassing

IF the TC is AF-type, with drive screw and A-type contacts
AND the TC is fairly cheap, like under US$50 shipped
AND you wouldn't mind making a bit of profit
THEN the TC is worth buying and re-selling

ELSE you may as well pass on it

11-22-2011, 01:37 PM   #5
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Glad to see I'm not the only one who has such purchasing decisions down to a science, hahaha!
11-22-2011, 01:44 PM   #6
Finknottle
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QuoteOriginally posted by RioRico Quote
Decision algorithm:

IF the TC is A-type, with aperture-control contacts on the mounts
AND the TC is pretty cheap, like under US$20 shipped
AND you are interested in macro and close-up work
THEN the TC is worth buying and de-glassing

IF the TC is AF-type, with drive screw and A-type contacts
AND the TC is fairly cheap, like under US$50 shipped
AND you wouldn't mind making a bit of profit
THEN the TC is worth buying and re-selling

ELSE you may as well pass on it
Thanks RioRico I'll certainly take that into consideration.
11-22-2011, 05:36 PM   #7
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QuoteOriginally posted by pxpaulx Quote
Glad to see I'm not the only one who has such purchasing decisions down to a science, hahaha!
A rough science, a bit of voodoo, a little abacus work, no problem.
11-22-2011, 07:08 PM   #8
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Don't forget to carry the 2.

11-22-2011, 08:29 PM   #9
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QuoteOriginally posted by pxpaulx Quote
Don't forget to carry the 2.
Don't mess with my 2-2.
11-22-2011, 09:41 PM   #10
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QuoteOriginally posted by RioRico Quote
Decision algorithm:

IF the TC is A-type, with aperture-control contacts on the mounts
AND the TC is pretty cheap, like under US$20 shipped
AND you are interested in macro and close-up work
THEN the TC is worth buying and de-glassing

IF the TC is AF-type, with drive screw and A-type contacts
AND the TC is fairly cheap, like under US$50 shipped
AND you wouldn't mind making a bit of profit
THEN the TC is worth buying and re-selling

ELSE you may as well pass on it
Now that's some pseudocode!
11-22-2011, 10:12 PM   #11
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QuoteOriginally posted by johnmflores Quote
Now that's some pseudocode!
I omitted the ENDIFs. I managed a fall-thru default, though. Whew. Good thing it's not in COBOL.
11-22-2011, 10:59 PM   #12
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QuoteOriginally posted by RioRico Quote
I omitted the ENDIFs. I managed a fall-thru default, though. Whew. Good thing it's not in COBOL.
Meh, what's a little syntax among friends?
11-23-2011, 01:34 AM   #13
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QuoteOriginally posted by johnmflores Quote
Meh, what's a little syntax among friends?
Pretty bad, if it goes OC7.
11-23-2011, 07:25 AM   #14
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If you can get a 2X converter cheap like $20 get it, if the image quality is poor just remove the glass and use it as an extension tube for close ups

Hans

Oops I see someone above already posted this.

Last edited by hnikesch; 11-23-2011 at 07:32 AM.
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