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01-13-2010, 06:45 PM   #1
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Old 1.4X converter on K100D Super??

Long time Pentax owner and user, but new to the forum.

Short history--------Way back when----I bought a new Auto 110 complete setup, I used it until the P3 came out and traded the Auto 110 system for it. I used the P3, for about 1 1/2 years and traded that on a EX+ Super Program, power winder, 2 zoom lens, a flash and 1.4X converter.

After using it for almost 10 years I got into other hobbies.
I want to get back into Photography !!!!!

So it's time to upgrade to a dslr !!! I don't need the top of the line, just a good DSLR, and from what I have read, Pentax still makes great equipment.

I soon am going to get a used dslr K100D Super, and want to know if the old 1.4X converter will work on the K100D Super??

I have the Pentax SMC 28-80 zoom, and SMC 75-300 zoom lens. Both of these lens were used on my Super Program and have the A ( automatic) setting on the lens.
Are there any special settings I should use using these lens with the K100D Super with or without the 1.4X converter???

Thanks for listening to the "newbie"

01-13-2010, 10:51 PM   #2
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The basic lens rules are: just about anything with a K-mount will attach to your camera, and lenses with A contacts work better. The A setting allows the camera body to control the aperture, so you see aperture information in the top display and viewfinder, it gets recorded in the digital file, all camera modes work as designed, the meter works fully - everything is roses. There's little reason to ever change that A setting.

Your teleconverter will be way more useful if it also has electrical contacts to pass through information from the lens to the camera. It's easy to tell; the mount end will have most or all of the contacts that the camera's mount has. These are even useful if the glass quality is awful - remove the glass for an extension tube with A contacts. (An extension tube with A contacts is as rare as snow in Houston.)

I'm not sure which exact lenses you have. If they are auto-focus too, they can tell the camera what their focal length is. That matters for the K100D's shake reduction system. For manual focus lenses, you'll have to enter that manually and change it if you zoom.

If you have lenses without the A setting, look in the beginner's forum for a sticky thread on how to use those too. A teleconverter without contacts will also "convert" all your lenses into non-A-setting lenses.
01-14-2010, 12:46 PM   #3
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QuoteOriginally posted by Just1MoreDave Quote
I'm not sure which exact lenses you have. If they are auto-focus too, they can tell the camera what their focal length is. That matters for the K100D's shake reduction system. For manual focus lenses, you'll have to enter that manually and change it if you zoom.

If you have lenses without the A setting, look in the beginner's forum for a sticky thread on how to use those too. A teleconverter without contacts will also "convert" all your lenses into non-A-setting lenses.
I just looked close at my lenses and the 28-70 zoom is a Pentax F series.
My other zoom lens is a Tokina 75-300( thought it was a Pentax---been so long since I looked at them.... ) and it has an "AF" and "Auto Focus" on it.Both have the "A" button and setting on them.

Thanks for the reply and information.
01-14-2010, 04:56 PM   #4
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I'd expect neither of those lenses to yield better results with the TC than by simply cropping the results without the TC, although given tha the K100D is only 6MP, tha might be less true than it is with higher resolution cameras.

01-14-2010, 08:28 PM   #5
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The tele-converter has 6 pins on it. Would this work with the auto focus or would I have to manually focus the af lenses ?
01-14-2010, 09:21 PM   #6
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The six pins will transmit aperture information to the camera. If you're really lucky, there's a screw-drive shaft about 30º away from those pins to pass through focus drive. Autofocus would be iffy with those lenses and a TC anyway, so you haven't lost a great deal if it's not there. The light and contrast loss from the TC make the AF sensors work hard.
01-15-2010, 09:13 AM   #7
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Keeping Marc's advise about less than stellar results with those lenses in mind --

If you can unscrew/remove the optical element from the 1.4X TC you'll end up with a moderate length extension tube with AE capability. You might find it more interesting as a close-up accessory than as a mediocre tele-extender with those lenses.

H2

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