Extension Tubes

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=260149456818&ssPageName=STRK:MEWA:IT&ih=016
Do you think this is a reasonable price for these extension tubes.
I maybe missing something here as the item description says manual focus only but i can clearly see AF on the 31mm tube and they appear to have all the metering contacts.

I would say too expensive.

I cannot be certain but they look very much like a set I bought years ago from Jessops. ie not Pentax brand. They did not fit very well and got stuck...i threw them away.

I recently bought a Pentax set on ebay....a manual exposure set for about £30. Much better quality and no nasty graunching noise when fitting them to the camera.

Working this close you dont need auto exposure.

I'd agree with this, if it is manual focus only.
My experience with a set of Jessops PK/A tubes has been excellent. They needed a little (simple) modification before they communicated aperture information between the lens and the camera, but they fit fine and I use them a lot.
If I saw a Pentax PK/A or better still, AF, set, I'd probably try and get them.
True, but it's still nice to be able to set the aperture from the body.

Thanks guys. The item description seems to contradict itself so i am not sure.
It is clearly shown on the item AF PK/A but no visible brand name.
Chris what sort of modification did you have to make. :

The 13mm tube says it is manual focus. I'm not sure this is a matching set.
I have a set of Soligor tubes, AF. I hardly ever use them and am considering selling them. I have only used them a couple of times, and decided they are not for me.

Basically, there are 7 contacts on the camera mount, but only 6 on the Jessops tubes.

But for the camera to swap aperture information with the lens, it seems that the 7th contact needs to be shorted through the metal of the tubes to the lens.

However the tubes are painted, so the 7th contact touches only an insulator.

The solution is to scrape a bit of paint off the tubes, where the 7th contact touches, thus:




Smoke and mirrors, but it works.

All credit to Mannesty for I got the idea for the fix from him. All I did was attack the tubes with a sharp instrument one night. They work fine now, and being able to set the aperture from the body is very handy.

Your right Gwyn, So its the tubes that are contradictory not the description.
Would you be willing to sell off those tubes to a poor Aussie and if so how much. Thanks

I understand what you are saying Chris thanks.

You have a PM

I have a set of Kenko tubes. They have an AF suffix and claim to be AF tubes. This apparantly means that they can be used with MF & AF lenses, but in manual focus mode only.

Manual focus is no big deal when shooting macro, in fact, I and many others prefer it.

Replied to your PM, I hope anyway i haven't used the PM before

Mannesty I am not to fussed about AF but still would like the metering from the body if possible. I know i can get those cheapy tubes from China for a couple of quid but prefer the better quality tubes.

Metering works fine on my Kenko tubes, and the Jessops set that ChrisA mentions. The Jessops tubes do need the mod for the 7th pin though.
Chris, thanks for the credit . . . again

I think any tubes will do as long as they have the requisite number of electrical pass-through contacts to convey lens info to camera and vice-versa. Some have even been known to use multiple sets to achieve astronomical magnification. Having ample light of course, is a must.

Thanks guys i have never used them before and i have done a stack of reading up on them and would like to give them a go.

When you sand off the black paint on these for the extra contact
make sure you have sanded enough for the maximum available aperture
on the lens to be transmitted through all 3 tubes. Very often only
the aperture setting is going through.
You only sand the one spot... just make sure that you do a good job.

Strangely I've got a set of Triplus tubes marked Pz AF with 8
contacts on the body side?

Despite saying AF they aren't AF, but are the Rolls Royce
of extension tubes.... really well made

Let's hope Clarky hasn't really been waiting for the last five years for that excellent advice