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12-23-2013, 06:28 PM   #1
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2X Teleconverter For K1000

I went to the camera store yesterday and I picked up some film and some other things. One of the things that I picked up was a teleconverter (on it, it says Calman Auto Tele Converter 2X For Pentax K). I plan on using this on my Pentax K1000SE (it's the only Pentax camera that I have). Does anyone have any information about this particular teleconverter and does anyone have any tips for using a teleconverter. I have never used one before.

12-24-2013, 04:11 AM   #2
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Not so much tips, as basic info. The teleconvertor should work fine on any lens on your K1000SE, but it will degrade the image quality somewhat. I don't know the quality of the teleconvertor, but some can be pretty bad. The 2x teleconvertor will double the effective focal length of the lens, but will reduce the available aperture by 2 stops. eg f/4-->f/8 and f/8--> f/16 so your viewfinder will look much darker, and correct exposure will require higher iso film or longer shutter speed, and focusing will become more difficult. Your camera exposure meter should take care of this though. But this light drop can be a major problem with AF on DSLR as most AF systems become dodgy above f/5.6. But on film and all manual, you should be able to get something.
12-24-2013, 09:00 AM   #3
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QuoteOriginally posted by KevinR Quote
Not so much tips, as basic info. The teleconvertor should work fine on any lens on your K1000SE, but it will degrade the image quality somewhat. I don't know the quality of the teleconvertor, but some can be pretty bad. The 2x teleconvertor will double the effective focal length of the lens, but will reduce the available aperture by 2 stops. eg f/4-->f/8 and f/8--> f/16 so your viewfinder will look much darker, and correct exposure will require higher iso film or longer shutter speed, and focusing will become more difficult. Your camera exposure meter should take care of this though. But this light drop can be a major problem with AF on DSLR as most AF systems become dodgy above f/5.6. But on film and all manual, you should be able to get something.
I keep hearing that a 2x teleconverter will cause you to lose two full stops of light but that always gets translated to losing a lens' two largest apertures. If you lose two full stops of light, could you lose two shutter speeds instead of losing two largest apertures? I realize that the aperture controls how much light will be allowed to enter a camera and shutter speed will control how long the recording medium (film or digital image sensor) will be exposed to the light that is being allowed in by the aperture and maybe it was just a stupid question or whatever. If using a 2x teleconverter will cause you to lose two apertures, can't you open up the shutter speed by two stops (make the shutter speed two stops slower) and regain the apertures that you have lost or is this just not possible?
12-25-2013, 12:56 PM   #4
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You don't actually lose the apertures, what they mean is you lose the equivalent of 2 stops, either in shutter speed or aperture, worth of light. The way in which the light is magnified reduces its intensity.
Put a lens on your camera and set the exposure correctly while aimed at something consistent like a grey wall, then take the lens off put the teleconverter on and put the lens back on without changing any settings and aim at the same thing you did before. Not only will the viewfinder be visibly darker, but you will see you are now underexposed. See how many stops of either aperture or shutter speed it takes to get back to where the needle is centered, in theory on a 2x it should be about 2 stops but i would be surprised if its that consistent.
If it turns out to have cheap glass and makes everything fuzzy you can remove the glass and use it as a macro tube. That same teleconverter with no glass would allow you to focus on things super close.
Just out of curiousity does the teleconverter have all the little electrical contacts for A series lenses on the ends of it? Most are the M series type that don't though your K1000 couldn't use them anyways.

12-25-2013, 02:46 PM   #5
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QuoteOriginally posted by PPPPPP42 Quote
You don't actually lose the apertures, what they mean is you lose the equivalent of 2 stops, either in shutter speed or aperture, worth of light. The way in which the light is magnified reduces its intensity.
Put a lens on your camera and set the exposure correctly while aimed at something consistent like a grey wall, then take the lens off put the teleconverter on and put the lens back on without changing any settings and aim at the same thing you did before. Not only will the viewfinder be visibly darker, but you will see you are now underexposed. See how many stops of either aperture or shutter speed it takes to get back to where the needle is centered, in theory on a 2x it should be about 2 stops but i would be surprised if its that consistent.
If it turns out to have cheap glass and makes everything fuzzy you can remove the glass and use it as a macro tube. That same teleconverter with no glass would allow you to focus on things super close.
Just out of curiousity does the teleconverter have all the little electrical contacts for A series lenses on the ends of it? Most are the M series type that don't though your K1000 couldn't use them anyways.
I do not see any electrical contacts on this teleconverter at all. I took some pictures of it though.
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