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05-21-2014, 08:12 PM   #1
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K-30 Extension tubes

I have a recently-bought K-30 and a set of Asahi Pentax auto extension tubes which I bought some years ago (at least 5 years or more ago). I tried them on my K-30 for the first time a week ago. They were extremely hard to put on, didn't focus no matter whether manual or auto, and after taking them off, my camera had exposure problems - way overexposed pictures.

Anyone else have this problem? And are there other extension tubes that will work with the K-30?

05-21-2014, 08:50 PM   #2
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Extension tubes are dumb- they force you for focus and meter manually. Follow the metering instructions for M lenses here:
https://www.pentaxforums.com/forums/54-pentax-lens-articles/110657-how-use-me...-x-k-7-a.html?

I recommend using live view for focusing, as tubes give you higher magnification. Even small turns of the focusing ring can have a huge effect on what's in focus, so you need to be both very careful and very patient.

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05-21-2014, 09:30 PM   #3
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There are no new extension tubes on sale for the past few years that provide auto functions.

1. Which auto tubes do you have? What auto functions if any does it have?
2. I'm assuming your lens does not have a manual f stop. If you don't have some of the auto functions your lens might only operate at the minimum F stop.
3. As Adam said auto focus isn't the best option. pre focus with live view on and move back and forth and let the camera tell you when you are focused.
4. Keep experimenting and and asking questions on this blog until you get your components to work.
5. Do you have a flash gun that you can use as a light source? Rigging up a white reflector above a flash gun will make a lot of difference.
6. I prefer manual settings
7. Once you have a system that works, write some notes. I took out my rings last week and it took a couple of hours to work out how to use them again.

Best of luck and keep asking questions and trying ideas out.
05-23-2014, 05:00 PM   #4
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I have one extension tube that is more difficult to attach than the others, it seems to be a little tighter. Inside diameter is apparently a little smaller. Otherwise they work fine, one is an extension tube, the other 2 are teleconverters with glass removed, which works great. (the extension tube and one TC are Makinon brand, all K mount.) Another one slips into place fine but is difficult to turn. It still works great and is no problem to remove, just tight to turn into place.

I agree with most of what Bob said, I use similar technique. Haven't tried live view, I don't seem to have much trouble with it through the viewfinder.

One thing to remember, extension tubes limit your focusing distance. My 135mm will only focus if within about 1 1/2 feet of the subject, the 50mm within a few inches, after attaching extension tubes. Outside those distances either way and no focus at all.

I also pre focus to infinity and move closer or further away to focus, it works better than the focusing ring, but I do use it now and then.

I use a folded envelope or business card to reflect the flash onto the subject with the 50mm, with the 135 the flash seems to work fine without it. With the 50mm it shoots above and past the subject, so the reflector helps direct the light, which is almost always needed, I rarely shoot macro without flash even in good daylight, since I'm usually using apertures of f11 or f16 to help with depth of field.

I don't have any auto focus lenses except the kit lens, so I always use manual focus, and all manual settings for exposure.

Keep trying, practice with it, learning macro takes time. I didn't get anything really good for a couple of months except for the occasional lucky shot.

Any K mount extension tube should work, but I would avoid the cheap Chinese ones, they don't have the aperture arm, so you have to open up the aperture to focus, then stop it down to shoot. Most of the time I would lose my focus so I put mine away and don't use them any more. You can also find K mount teleconverters at good prices and remove the glass, that works great. I have one I can use for both, it has a shoulder that stops the glass in the correct position so I can put it back in any time. Just make sure whatever you use has the arm to manipilate the aperture, it helps a lot. It holds the aperture open so you can see to focus, then stops it down to take the picture, same as a lens does.

05-24-2014, 05:59 PM   #5
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Thanks, Paleo Pete. Some good suggestions.
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