Raynox/Extension tubes


Dr. Mhuni

Link Posted 16/11/2008 - 12:10
I had my eye on some Kenko Auto Extension Tubes at Warehouse Express to get when I'm back in the UK at Xmas which were going for £80, but these have now gone. Have done a search for Kenko tubes (Pentax)elsewhere and come up with very little and what there is is priced at £120 + p&p & I'd have to wait several weeks for them to get them in stock. Canikon & Minolty going for just £80. The first time I've been disappointed at having a Pentax. Even SRS have no Pentax tubes (but do have ones for Canikon).

Anyway, £120 is too much - it's approaching the price I could get a new macro lens for from a shop (when you take off the tax I get off as a non-UK resident). But I've just come across the Raynox 250 52-67 Close Up, and this looks like a cheap alernative - a good way to start macro perhaps? (Also seen there is a 150 - is one better to start with than the other?)

Can anyone tell me what the quality of the Raynox is like compared to Tubes?
Mhuni

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Mannesty

Link Posted 16/11/2008 - 13:51
I have the 150 version and the few shots I've taken with it seem very sharp. I keep it with my 'lightweight' kit for when I don't want to carry heavy macro lenses around.

I don't know what the differences are between the 150 and 250, sorry.
Peter E Smith

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fatspider

Link Posted 16/11/2008 - 17:23
Have you considered buying used? theres nothing much to go wrong with extension tubes and as theres no glass involved it doesn't really matter on the make.

I dont know if the Kenko ones you mention are Auto AF or just Auto, but I would have thought a good set of used "A" mount tubes would cost less than £40, and your going to want to focus manually anyway.
My Names Alan, and I'm a lensaholic.
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Dr. Mhuni

Link Posted 17/11/2008 - 05:10
I've been keeping an eye out for secondhand ones, but very little has come up of late. Thought the Raynox might be an acceptable alternative - and perhaps more convenient than extension tubes, as they fit on the front of the lens.

Re. the difference between the Raynox 150 & 250 - I think it's magnificiation, though haven't properly investigated this yet.
Mhuni

500px

Peter Elgar

Link Posted 17/11/2008 - 13:35
I bought Pentax K fit Vivitar tubes for £38 brand new from Jessops.They work on my digital and film Pentaxes OK.
been a member of Pentax Club since the Ron Spillman era! Got COMPUTERISED at last - DIGITISED? Taken the PLUNGE - BUT FILM STILL RULES !!!

Dr. Mhuni

Link Posted 18/11/2008 - 05:26
Just did a search on Jessops and all I came up with was some 6x7 tubes at £270! Did you get your Vivtar tubes recently?
Mhuni

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Peter Bargh

Link Posted 18/11/2008 - 09:07
As it has glass in it, it will have an inferior performance to using tubes. We did source Kenko ones for a while which were very good, but they have ceased production.

We have an alternative tube option for £12 that we're about to add to our system. It's a set of three screw thread tubes with a K bayonet mount at each end. You can unscrew and take out any combination of the three interior screw thread tubes to change extension, giving a choice of four magnifications.

Dr. Mhuni

Link Posted 19/11/2008 - 05:32
I'm certainly interested in the tubes Peter. Could you tell me what information they relay from/to the lens. I assume they're not autofocus, but do the other auto functions still work on a lens? Also, could you let us know when they will be available?
Mhuni

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Peter Elgar

Link Posted 19/11/2008 - 09:55
Dr. Mhuni wrote:
Just did a search on Jessops and all I came up with was some 6x7 tubes at £270! Did you get your Vivtar tubes recently?

I got them must have been about 10 years ago.
been a member of Pentax Club since the Ron Spillman era! Got COMPUTERISED at last - DIGITISED? Taken the PLUNGE - BUT FILM STILL RULES !!!

Peter Bargh

Link Posted 19/11/2008 - 10:41
The tubes are now online. Pentax K fit Extension Tube Set.
Quote:
Could you tell me what information they relay from/to the lens.

There is no coupling whatsoever. Totally manual. I've tried them on the K20D using the standard 18-55mm lens. This lens is not the ideal one but you'll see from the link above it's still really good quality.
Problems you will encounter. The tubes don't cock the aperture lever open so a lens without an aperture ring, like the modern DA's etc will be operating at the smallest aperture. This makes it impossible to focus, and results in a long shutter speed.
Therefore the tubes are best used on lenses with manual aperture rings. I'd probably use them with an old 50mm f/1.7, or 100mm if I needed more camera to subject distance.
When using them to take the photos in the link above I used a blob of Blu-Tack to lock the aperture stop down lever open at mid aperture, so I could focus and use a more useful "optimum" aperture.

Dr. Mhuni

Link Posted 22/11/2008 - 08:23
Thanks for that info Peter. Though I would prefer tubes which at least allow you to make some auto-adjustments, as I will probably use them with my DA zooms.

Can anyone clarify something for me - am I right in thinking that tubes referred to as 'Auto' do have some coupling that allows for adjustments to be made from the camera (though only the more expensive ones enable auto-focus)?
Mhuni

500px

gartmore

Link Posted 22/11/2008 - 09:24
With tubes, the word 'auto' usually refers to 'automatic diaphragm and nothing else. I have jessops own brand ones which have all but one of the Pentax K electrical contacts. Mannesty discovered that by scraping a little of the paint of the tubes, thereby creating another contact they work perfectly with the newest lenses. BTW you wouldn't want auto focus when using extension tubes. As Peter rightly says, zooms are not a good choice for this sort of work. A 50mm prime would be ideal. Pentax used to make a 50mm Bellows lens specifically for close up work which had no focusing ring.
Ken
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -

smc

Link Posted 26/11/2008 - 21:56
You might search for a Vivitar 2x macro converter. It is an excellent piece of kit giving up to 1:1 macro and often for less money than extension tubes.
Last Edited by smc on 26/11/2008 - 21:56
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