A question about auto extension tubes
In macro work most people switch off AF anyway.
Best regards, John

They are not cheap should you find a set.
K-1Gripped K-1 ungripped K-5ii K7 Various lenses
Stuart..
A pity they have stopped making them for Pentax.
Hi all, I'm looking tp purchase a set of auto extension tubes. But also need them to be auto focusing. Can anyone give me information of the better brands to purchase.
Don't know the quality and it's only a 25mm piece but it looks ok
http://srb-photographic.co.uk/pentax-k-auto-extension-tube-5913-p.asp
You can get a new 2x AF TC for about £110, a used one will be less but they are quite hard to find. They won't give much extension, less than a full set of tubes, but if AF is critical for you this will be your best bet.
Personally, I find AF of very limited use for macro work as the Depth of field is often so thin that using AF is not practical.
Regards
David
Flickr
Nicola's Apartments, Kassiopi, Corfu
Some cameras, some lenses, some bits 'n' bobs
Personally, I find AF of very limited use for macro work as the Depth of field is often so thin that using AF is not practical.
This +1
If autofocus is really that important (and you've got to ask how the camera is supposed to know exactly what part of the object you want to be the focus point anyway) then perhaps a dedicated autofocus macro lens would be worth looking at, given the costs associated with achieving autofocus via the extension tubes approach.
I do a fair amount of macro work. I never use auto focus because when I tried to use it years ago, the camera got it wrong more often than not. When I've tried it more recently with a modern camera, it still gets it wrong.
For macro, use manual focus and put the money I've saved you towards a dedicated macro lens. Much more useful.
Peter E Smith
My flickr Photostream
Jessops made a set, I have some. Beware that the naive people who designed them didn't realise that the body of the lens/tubes is part of the electrical circuit that is used to determine aperture setting in A mode.
The Jessops tubes are anodised and thus the circuit won't make. You have to get a file and remove a portion of it on each tube in order for them to work.
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
Hi all, I'm looking tp purchase a set of auto extension tubes. But also need them to be auto focusing. Can anyone give me information of the better brands to purchase.
Don't know the quality and it's only a 25mm piece but it looks ok
http://srb-photographic.co.uk/pentax-k-auto-extension-tube-5913-p.asp
Thanks for that link. I've been looking for af tubes for pentax for as long as I've been into photographing dragonflies and butterflies. I often use auto extension tubes with my FA*300 F/4.5 to improve close focus. It would be so much easier with af tubes. Trouble is I normally use 65mm of tubes, oh well, can't have everything I guess. Although I see that KooKa also do a set of 20 and 36 tubes as seen here link perhaps srb will get them if I ask nice....

Walt
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K-1Gripped K-1 ungripped K-5ii K7 Various lenses
Stuart..
In reply to why I want Auto focusing tubes. Is that when I'm shooting, I like to hand hold my camera. I sometimes use my 70-200 f2.8. After a period it becomes a little heavy and is awkward to hold. I sometimes find that when I try and manually focus on my subject. They quite often fly away before I've completely finished my focusing routine. I think Af tubes would help me get a far greater hit rate.
I took this... with extension tubes with a manual focus 50mm 1.7 A lens.
Set your aperture up, but I've found it doesn't give much more or less of a depth of field unfortunately, so I opt for nearly fully open on the lens.
Then set your focus at a distance you're likely to be able to get to your subject in the field. Set the camera for live view (with focus peaking enabled) if suitable for the shot and set it to rapid fire shooting mode. Move the camera in and out to do the focussing.
Seriously the field of view is so damn shallow with the tube the subject will be well gone before you get a chance to get it all right.
stub
Member
Manchester
K-1Gripped K-1 ungripped K-5ii K7 Various lenses
Stuart..