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07-05-2015, 08:44 AM   #1
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Pentax-K Adapter for 645

I had a (small) surgery a couple of days ago and can not go out for a week or two so my only playground these days is at home or in my garden.

I mainly take pictures (black&white) with my Pentax 645 NII (I have 2) and start to have a good collection of 645 lenses.

For digital I also have a K3 that I mainly use when I need to do color work.

One day I hope to buy a Z but right now is stay analog.

Last year I bought a Pentax-K Adapter for 645 that I hardly used (because my K3 lenses are quite good).
When I bought it (used from eBay) it was difcult to find information on adapters so this small review.

Putting the adapter on is staight forward and it is not heavy.
With the adapter you loose the autofocus so forced to go for manual focus (not an issue but you need to be aware of it).
As usual as soon you are in focus a small 'beep'/sign in the viewfinder informs you that the object is in focus.

I also have the impression that you can only do spot metering with the adapter on as I was not able to make changes to the default metering.
When you go to F11 or higher it can become quite 'dark' in the K3 viewfinder but not an issue when wide open.
(So the more you close the aprture the less bright the viewfinder is).

The medium format lenses on the K3 can look heavy but with the smaller ones like the FA75, FA150 or even the A120 it is ok.
(I am used with the 'heavy' lenses so no issue although they feel better at home on my 645).

As I am not able to move around a lot I though it could be a good to take some pictures in the garden with the SMC Pentax-A 645 120mm F4 Macro put on my K3 so that you have some examples.

I am not a macro shooter but I thought that the results were not that bad (at least made my wife happy to see some of her flowers in the PC).

Although we are at F4 if find that we still have a very narrow depth of field and I like the bookeh.

So all pictures were taken with the K3 and the A120mm lens. AV mode. Is switched shake reduction off. No changes were applied (I imported the raw in lightroom and exported into JPG). I used a monopod as sometimes the speed was slow.

Below some examples.

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07-05-2015, 10:25 AM   #2
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jatrax's Avatar

Join Date: May 2010
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I just checked the Lens Database and noted 12 people viewing the entry for the A 120mm Some sellers on ebay are going to be happy I think

Really very nice shots!!
07-05-2015, 12:11 PM   #3
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Join Date: Dec 2014
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That looks like an incredible piece of glass. Great images. Thanks for sharing.
That "F4" would put many fast primes to shame
07-05-2015, 01:55 PM   #4
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Join Date: Oct 2012
Location: Southern Michigan
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With the coming of the full frame, it would behoove Pentax to release a new 645 lens to k-mount adapter that retains full automation. 645z shooters who are new to Pentax would be more likely to pick up a FF or a K3ii as a back-up body if they could use their 645 lenses on it.

07-05-2015, 06:57 PM   #5

Join Date: Feb 2011
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Those are some great looking pics. The 645 120 macro is a superb lens on the K-3, and I can only imagine it on the Z or one of the 645 SLRs.

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