About extension Tubes

I'm a old Pentaxian since 1970, I did mani photos in dia, Bw and Color negatives.

I stopped to proiect dias and so I began to duplicate all of them.

With my K 20 I found that , with extension tube, was more simple and better than to use scanner, the only was the necessity to use a35 mm than a 50mm, cause the APS-C format of K20.

Now I finally bought a K1 ii and so I proved to make duplication with it and a smc 50mm; astonishing difference for color and all, but I relize that K1 made photos only at all open diafgram, whe I searced to stay at around f 11 for deep of field, only center in focus .

K1 and my tubes don't work together.

Thera are a lot extension tubes to sell, but I'm afraid to buy something with the same problem of mine; I need to use my 50mm all in manual.

If someone has an answer to this I'll appreciate very much!

Greetings from Italy.

You need to set your K1 to work with the aperture ring on your smc 50

In the Custom menu 5 "Use Aperture Ring" Set to 2

Kleon wrote:

I'm a old Pentaxian since 1970, I did mani photos in dia, Bw and Color negatives.

I stopped to proiect dias and so I began to duplicate all of them.

With my K 20 I found that , with extension tube, was more simple and better than to use scanner, the only was the necessity to use a35 mm than a 50mm, cause the APS-C format of K20.

Now I finally bought a K1 ii and so I proved to make duplication with it and a smc 50mm; astonishing difference for color and all, but I relize that K1 made photos only at all open diafgram, whe I searced to stay at around f 11 for deep of field, only center in focus .

K1 and my tubes don't work together.

Thera are a lot extension tubes to sell, but I'm afraid to buy something with the same problem of mine; I need to use my 50mm all in manual.

If someone has an answer to this I'll appreciate very much!

Greetings from Italy.

There is just this thread about prbolems with extension tubes and problems with K3 in this forum:

https://www.dpreview.com/forums/post/64528788

Maybe you find the answer there. If they worked with K20 I see no reason why they shuld not work with K1. Did you allow the use of aperture ring in the menu setting?

Best regards

Holger

There are three "levels" (maybe four?) of extension tubes.

The simplest (and cheapest?) are simply tubes with k-bayonette mounts at each ends. They haven't got the coupling lever and the lens then acts a a purely manual lens that stops down when you turn the aperture ring. If it doesn't, the photo will be taken with the aperture wide open even if you have stopped it down with the ring. The only lens I have that would work with this kind of extension tubes is my 28mm shift lens, a fun but complicated device that I'd never use for macro shots. I guess that old m42 screw mount lenses with a k-mount adapter would work.

Next level is marked as "automatic". This simply means that there is an aperture coupling lever, and the lens will stop down to the chosen aperture when you take your photo. But it still acts as a manual lens, you have to set the aperture with the aperture ring and use the green button or d o f control to set the correct exposure. And you have to choose the "use aperture ring" option in the menu.

Third level are tubes with both the lever and the electric contacts for aperture control from the camera body. With these tubes, lenses with an "A" setting on the aperture ring work just like they do without the tubes. Just set the ring to "A" and handle the rest from the camera body. After much search I actually found this type of extension tubes, used on ebay. They are only marked "made in Japan", no brand name or anything like that. But they do work well.

The possible fourth level would be tubes that also have the autofocus screw. I have never heard of or seen such tubes.

Kjell

I've just tested the use of extension tubes on both my K1 and K5, and they work exactly the same way on both cameras. The tubes are manual Vivitar ones with only an aperture lever linkage.

Using them "as is" produces the same results as that of the OP: The aperture of the lens does not close down. The problem in my case is the anodized black finish of the tubes: It prevents the tubes from shorting the electronic contacts on the body, as a normal lens would do. Using an aluminium strip between the tubes and the lens mount to short the contacts results in the aperture closing as it should.

Also: The use of the aperture ring should be selected in the menu, as pointed out by other posters, the camera should be in manual exposure mode ("M"), and the focusing mode should also be Manual (not absolutely sure about the last one, though).

In my case a permanent solution could be to sand off the anodized finish on the part of the tube which makes contact with the electronic contacts on the body; or fix a piece of aluminium foil to that part. Of course, all your tubes (they usually come in sets of three) should be treated that way in order to work with the camera.

I understand that you have a mechanical problem, but in addition to that the camera body contacts also have to be shorted to allow the closing of the aperture.