[aitrus3]

Hi there,

I e-mailed pentax a while ago wondering if they made any auto extension tubes for their cameras. They sent me one back saying they made theAuto Extension Tube set B still and that they had some in stock. However, nobody i can find has them in stock and the only promising place is based here in B.C. in Vancouver. THey say that pentax is going through internal changes and they won't be able to order, tell me a price, or offer any more details until mid april.
Anyone out there know of where i might be able to find these? And also, do they have the elictrical contacts? Pentax said they were auto but l've seen some pictures and i didn't see any elictrical contacts...
If i can't find any, I might just try and build my own (don't worry, i have a milling machine at my disposal...)
Thanks!
P.S. I have the sigma 70-300 tele/macro lens however, it's not a true macro as it only offers up a 1:2 magnification ratio... i want something closer as this doesn't really fill the frame enough for me. In fact, I've found that it really only magnifies a little more than what my 18-55 can when i get right up close to the object...

[Peter Zack]

It's Auto in aperture linkage only. This was a film era part. There are no modern replacements from Pentax. But what you can do it get a cheap 2x or 3x teleconverter off Ebay that has the contacts. Then take the glass out (very easy) and voila! Auto extension tube. You can even get 2 and stack them as long as they fit tight and don't loose contact with each other (shouldn't be an issue).

You might have a milling machine, but to make the electrical connections could be a bit more tricky.

I assume you are talking about using this with a different lens. The best might be a fixed 50mm or so.

[Blue]

SRB-Griturn as the set that has contacts for auto-metering but probably not AF but they go for 163.5 pounds.


SLR Auto Extension Tubes

Kenko used to make a 25mm AF tube but stopped. They come up 2 or 3 times a year for about $80-120 and I would need 2 of them at least.

[aitrus3]

I don't use AF anyways (i prefer manual, as i still find it faster than trying to use auto, no matter that i am doing) so all i was curious about was to know if I could still control my aperture, because yes, the lens i want to use with them is my 18-55mm and it doesn't have an aperture ring. i realize that a too small of a focal length makes it impossible to focus when using extension tubes so I'd really only stick to around the 50mm range anyways.
So thanks for the info
Greg

[Peter Zack]

I did what I posted earlier. I wanted one of the Kenko's Blue mentioned and realized that just taking the glass out of a 2X TC would do the job for about $30.00 Works just fine.

[gofour3]

Hi there,

I e-mailed pentax a while ago wondering if they made any auto extension tubes for their cameras. They sent me one back saying they made theAuto Extension Tube set B still and that they had some in stock. However, nobody i can find has them in stock and the only promising place is based here in B.C. in Vancouver. THey say that pentax is going through internal changes and they won't be able to order, tell me a price, or offer any more details until mid april.
Anyone out there know of where i might be able to find these? And also, do they have the elictrical contacts? Pentax said they were auto but l've seen some pictures and i didn't see any elictrical contacts...
If i can't find any, I might just try and build my own (don't worry, i have a milling machine at my disposal...)
Thanks!
P.S. I have the sigma 70-300 tele/macro lens however, it's not a true macro as it only offers up a 1:2 magnification ratio... i want something closer as this doesn't really fill the frame enough for me. In fact, I've found that it really only magnifies a little more than what my 18-55 can when i get right up close to the object...

Kerrisdale Cameras in North Vancouver have a used set of these Pentax Extension tubes for $99.50.

http://www.kerrisdalecameras.com/products.html?catalog[decision_model_guids]...log[offset]=15

One thing to note is some of the “auto” extension tubes will suffer from a stiff diaphragm linkage over time and will need to be lubricated. (The set at Kerrisdale suffer from this) Using these "Auto" tubes without lubrication will make it hard to move your lenses aperture ring. I sent mine to Eric for lubrication and they are much better.

You maybe better off getting a "Manual" set without the linkage, they go for about half the price and there are no issues with them other than you have to use stopped-down metering.

Phil.