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11-09-2013, 01:24 PM   #1
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sa/kpr lenses

hello ... am possibly showing my ignorance but would someone please tell me whether a Sigma SA/KPR 28-80mm lens will fit onto my k30? is auto focus available? anticipated thanks

11-09-2013, 01:37 PM   #2
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There is no SA/KPR mount, they are two different mounts. The SA mount is Sigma's mount for their bodies, Sigma lists Pentax compatible lenses as KPR (K-mount Pentax/Ricoh).

The confusion comes from the cap, Sigma prints SA/KPR on the cap because they are similar enough that the cap fits either, but they are not compatible when it comes to mounting on the camera.

Do you have a picture of the mount?
11-09-2013, 01:48 PM   #3
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from your answer and other digging around it would seem that this lens will NOT fit my k30. the seller has it advertised as being suitable for pentax but (when written to/asked) he can't/won't confirm this. I will just steer clear. thank you for reply
11-09-2013, 02:08 PM   #4
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Is it this one?

Sigma SA/KPR 28-80mm fit Pentax/Sigma Fit Brand New Macro Button Awesome Lens | eBay

I'm pretty sure that is a Pentax mount one, since it has an aperture ring with the A position on it, so it will fit your K-30 and all functions will work fine. A Sigma SA mount version does not have an aperture ring.

11-09-2013, 02:16 PM   #5
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yes .. that's the one I was looking at.
am looking for a good/inexpensive (as opposed to great/expensive) macro and this (on the face of it) seems to fit the bill.
good detective work by you.
thank you
11-09-2013, 03:10 PM   #6
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I have that lens. Works great on my k10 and k7. Very fast autofocus. It is a fairly sharp lens, but the macro is not really macro, just close up. It works well in that mode though. If you are looking for a real macro lens you may find one of the old Pentax manual focus 100mm f4 or the 50mm f4 fairly cheap. They are both manual lens, but are excellent.
11-09-2013, 09:01 PM   #7
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thank you for the recommendation
11-09-2013, 09:23 PM   #8
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obviously 'cheap' is totally subjective .. with one mans 'that's cheap' being another mans 'how much!'
having looked at the prices of the 50 and 100mm f4 macro lenses I am the latter man.
other (cheaper) alternatives are invited/welcomed

11-10-2013, 02:24 AM   #9
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For macro, the cheapest option is extension tubes and a cheap manual prime lens. It is less convenient than a dedicated macro lens, but it can definitely be very cheap.

What kind of magnification are you looking for? What kind of working distance? What do you currently have?
11-10-2013, 03:39 AM   #10
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QuoteOriginally posted by elliott Quote
For macro, the cheapest option is extension tubes and a cheap manual prime lens. It is less convenient than a dedicated macro lens, but it can definitely be very cheap.

What kind of magnification are you looking for? What kind of working distance? What do you currently have?
would like to be able to photograph the hairs on a skunks scrotum...only joking!
filling the lens with a spider would be good/ok
I currently have a 35mm f2.4 lens..which I'm guessing will work well with extension tubes.
given what they (extension tubes) DO would I be right in thinking that I don't need
be too fussy with what brand I buy?
am guessing that I'll be confined to manual focussing.
other lenses: sigma 50-200 dc os hsm...pentax 18-55mm DA .. 28-70 fa
anticipated thanks

Last edited by stefan22; 11-10-2013 at 04:40 AM. Reason: additions
11-10-2013, 05:27 AM   #11
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Just a simple note here, with respect to sigma mounts.

Pentax had in the era of the KA mount licensed it to both sigma and Ricoh and gradually the other manufacturers did not follow the same migration path as Pentax, hence the Ricoh pin and the difference today in the sigma and pentax mount

But for a while, all three were compatible
11-10-2013, 05:32 AM   #12
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The absolute cheapest possible thing you could do is reverse the 28-70 in front of the 50-200.

Of course the auto focus must be off, the extra weight could cause a problem and auto focus is mostly useless for macro anyway. You'll focus by moving the whole camera.

Before buying anything you can see how this will work by just holding one in front of the other. Mount the 50-200 on the camera normally. Make sure the aperture ring on the 28-70 is at f4. Hold the 28-70 backwards in front of the other one (filter ring to filter ring). Pick a subject and slowly move forwards and back until the subject is in focus. You can change magnification by changing the zoom of the lenses. Just play with it to get a feel of the limits and see if it will work for you.

If you think you can live with this setup, get a male-to-male filter ring. I believe the Sigma is 55mm and the Pentax is 52mm, so something like this would work:
Double Male 52mm-55mm 52-55 55-52 mm Macro Reverse Ring | eBay

It is not the most practical setup in the world, but it will work.
11-10-2013, 05:07 PM   #13
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I WILL try this but it does seem to be a very cheap (3) cruelly convoluted way of creating macro
11-10-2013, 09:20 PM   #14
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May be it's time to read this article by RioRico; the above described way is in there and it gives you Macro with a capital M

https://www.pentaxforums.com/forums/54-pentax-lens-articles/152336-cheap-macr...lose-work.html
11-10-2013, 10:49 PM   #15
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QuoteOriginally posted by sterretje Quote
May be it's time to read this article by RioRico; the above described way is in there and it gives you Macro with a capital M

https://www.pentaxforums.com/forums/54-pentax-lens-articles/152336-cheap-macr...lose-work.html
read it (sort of) ... phew!
well .. I did ask.
thank you (kind of)
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