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Wanted: Extension tubes set for K-3II/Pentax 100mm macro

Posted 14/03/2024 - 15:31 Link
I am keen to try my K-3ii/Pentax 100mm macro lens with extension tubes however, given by as yet limited experience with Pentax digital cameras/lens/accessories, may I solicit advice from learned members here in the forum?

I would prefer fully auto if possible (inc auto focus) and I see the internet is awash with such devices, including some weird advice about scratching off paint !!!, 6th contact (which my lens doesn't have) etc etc

Any advice would be most appreciated and if anyone has a suitable set they want to part with I obviously would prefer to keep it in the family so to speak.

Thanks in advance.
Spad
Posted 14/03/2024 - 15:48 Link
Ive got a set and a macro rail that you might be interested in?

Theyre sat collecting dust. I'll dig them out and post photos.
The Legendary Terry Pratchett once said:
At the beggining there was nothing....

Which exploded....
LennyBloke
Posted 14/03/2024 - 16:14 Link
You will struggle to find any extension tubes that are Auto-Focus - many will say AF on the barrel but that usually just means they fit Pentax AF cameras. There is an AF tube available going under various names (Micnova I think was one) but having tried it myself I would advise you to steer clear of it - it works with some lenses but not others and has a nasty habit of getting jammed on lenses/bodies.

You are correct about the "scratching off the black paint" scenario - several manufacturers (Jessops being the best known one) made their tubes without the chrome surface on the mounting plates - this was fine for some earlier lenses, but later lenses couldn't carry all the info between lens and body (i.e. Aperture setting) without having a small area of black paint removed. I've done this myself and as long as you do a neat job it is perfectly workable.

My recommendation would be to use Triplus PKAF tubes (set of 3 - 13mm, 21mm and 36mm I think) - they are engineered beautifully and carry all info through without modification. SRS have a used set in stock at 59, or alternatively I may have a spare set somewhere

Hope that helps!

EDIT: Didn't you buy my set of Triplus tubes quite recently? Are you not getting on with them? If you want some advice/help just shout
LennyBloke
Edited by LennyBloke: 14/03/2024 - 16:17
Lubbyman
Posted 14/03/2024 - 16:22 Link
As Lennybloke says, you won't get autofocus with extension tubes. Tubes called 'auto' will allow other auto functions, but check carefully which functions are supported by the specific set of tubes you're looking at. Lack of autofocus isn't a major problem as at typical macro magnifications and narrow depth of field manual focus is more trustworthy. In fact, with tubes so much of the image is likely to be out of focus that keeping an eye on what that looks like can be just as important for the final image as keeping an eye on what's in focus. And if you ever get into focus stacking, it's got to be manual everything.

If you want more magnification with auto everything including focus, the Pentax 1.4 teleconverter will do it. It plays well with my macro lenses, although I can't vouch for the Pentax 100mm as I don't have one. It will also retain the same minimum working distance (from front of lens to subject) whereas tubes will reduce it. That might be important if you're photographing bugs and beasties that can be spooked if you get to close. However, the 1.4TC is, of course, much more expensive than tubes!

Steve
Posted 14/03/2024 - 17:29 Link
LennyBloke wrote:

...EDIT: Didn't you buy my set of Triplus tubes quite recently? Are you not getting on with them? If you want some advice/help just shout

OMG LennyBloke, you are right, I did buy them It seems that my age-related short-term memory loss has struck again. Looking back at the date I recall having to deal with some serious issues at that time so I'm guessing my old grey cells just couldn't cope. I have now found them, still in their packaging, at the back of my cupboard and I'm looking forward to strapping them on and getting back into some macro stuff.

I did lots of macro stuff 10-15 years ago using a FF camera, macro lens + tubes so I'm looking forward to seeing how this combination matches up.

Apologies for my memory lapse to all who took the trouble to read and reply - I'll go stand in the naught corner for an hour as penance - if I can remember where it is.
Lubbyman
Posted 14/03/2024 - 17:53 - Helpful Comment Link
And while you're looking for the naughty corner, keep your eyes open for a packet of Tescos breadcrumbs that I know I bought but can't find in any of the places it should be. Your old grey cells are not unique!

Steve
LennyBloke
Posted 14/03/2024 - 20:01 - Helpful Comment Link
I'm clearly in good company with you Yorkie and Lubbyman - but I forget why
LennyBloke
Posted 14/03/2024 - 20:31 Link
Thanks for making me feel not quite so gormless guys I'm on my 82nd orbit around the sun this year and if I can continue to remember which hole in the camera to look through and which button to press then I'll carry on.
cbrog
Posted 15/03/2024 - 12:10 Link
Bah.!...mere children all of 'e

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