[ivanvernon]

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This lens club is for all those who are using either Pentax 645 lenses or Pentax 67 lenses on the Pentax K-1 and any full frame successors. The purpose is to display images and encourage discussion and exchange of views and experiences regarding the use of medium format lenses on the Pentax K-1 or other Pentax full-frame digital cameras that may become available. To join, simply post to the Club with some indication of your equipment and interest.

I will begin by describing my experience. I have the Pentax 645D as well as the K-1, and have quite enjoyed using all the K-1 capabilities with my medium format lenses. I have around five Pentax 67 lenses and 20 Pentax 645 lenses. My primary interests are flower, landscape, and portraiture photography, and I am strictly an amateur, though I have done a few weddings in the past. I would like eventually to post images from each of my medium format lenses as used on the K-1, along with brief comments regarding my experience with each lens.

Come on. Jump in and share your experiences and images.

[Fcsnt54]

This is great. Will be looking forward to the images in this thread. I might eventually contribute. My favorite lens to use on the k-1 is the 645 LS lenses primarily the 135. Great character and colors. It is just a hobby for my, but i like using this combo for portraits and some landscape as well.

[ffking]

I'm hanging onto my lenses for the 67D anyway, but I don't have a K-mount adaptor - maybe next on the list (which is quite a few purchases down )

[ivanvernon]

This is great. Will be looking forward to the images in this thread. I might eventually contribute. My favorite lens to use on the k-1 is the 645 LS lenses primarily the 135. Great character and colors. It is just a hobby for my, but i like using this combo for portraits and some landscape as well.

I agree. I have two of those 135LS lenses, and use as LS lens on the 645D and as a standard lens on the K-1. I have only used it once on the K-1, but definitely found it to be an excellent, sharp lens, and I plan to use it more in the future. I also have the 75LS, and have also used it on the K-1 as a standard lens. So far as I am aware, there is no way to use either the 75LS or the 135LS as LS lenses on the K-1.

---------- Post added 10-23-17 at 02:44 PM ----------

I'm hanging onto my lenses for the 67D anyway, but I don't have a K-mount adaptor - maybe next on the list (which is quite a few purchases down )

Good to hear from you. You can get a cheap Chinese P67 to K adapter for about $7-10. I see no point to paying the big bucks for a genuine Pentax adapter, since it is mechanical only and does not provide any form of communication with the camera.

[ffking]

Good to hear from you. You can get a cheap Chinese P67 to K adapter for about $7-10. I see no point to paying the big bucks for a genuine Pentax adapter, since it is mechanical only and does not provide any form of communication with the camera.

That's good to know - I might just have a look at that - thanks

[baro-nite]

I expect to have a K-1 by the end of the year, and I've been using a 645n kit since 2014. After much consideration I've decided to try the Mirex tilt/shift adapter, to get a "digital back" for my 645 lenses. While the adapter does have the significant limitation that the tilt and shift axes are fixed in relation to each other, I've decided that the ability to do shift panoramas (with optional tilt) justifies the cost of the adapter for the uses I have in mind. I'll be ordering the Mirex adapter soon, and will be looking out for Black Friday / Cyber Monday specials on the K-1. Thanks for starting the club!

[mattb123]

What 645 to K adapter do you like? I just have 67 to 645 but not down to K.
Last time I looked they seemed expensive, like $100 or so.

[ivanvernon]

What 645 to K adapter do you like? I just have 67 to 645 but not down to K.
Last time I looked they seemed expensive, like $100 or so.

The Pentax ones are quite expensive, $100+. However, the adapter is totally mechanical, having no electronic connections. Therefore, I can see no real reason to buy the Pentax one, and instead just picked up a couple of cheap Chinese adapters which seem to work fine. I think they were no more than $15-20 each for the 645 and 67. Eventually, I will splurge ad get the Pentax ones, just not yet.

---------- Post added 10-23-17 at 05:13 PM ----------

I expect to have a K-1 by the end of the year, and I've been using a 645n kit since 2014. After much consideration I've decided to try the Mirex tilt/shift adapter, to get a "digital back" for my 645 lenses. While the adapter does have the significant limitation that the tilt and shift axes are fixed in relation to each other, I've decided that the ability to do shift panoramas (with optional tilt) justifies the cost of the adapter for the uses I have in mind. I'll be ordering the Mirex adapter soon, and will be looking out for Black Friday / Cyber Monday specials on the K-1. Thanks for starting the club!

I will look forward to learning from your experience. Please keep us posted.

Thanks. I have been enjoying these lenses so much on my K-1 that I felt it would be interesting to hear from others.

[mattb123]

I see a few of those around but they are more expensive than the 67 one ($37). Just wondering if you had a link to a truly cheap one.

[ivanvernon]

Here are some test shots taken outside in my yard just now under late afternoon rainy skies. This is the Pentax-A 645 45mm f 2.8. This lens does not get much love, and clearly in terms of sharpness it suffers in comparison with the two lens that bracket it on either side of the FOV continuum, the outstanding 35 and 55. On film, for which this lens was designed, I believe it would be quite adequate, and I still like it for its color fidelity and rendering. I also have the FA version which has a similar optical description--9 elements in 8 groups--but have not made direct comparisons between the A and FA versions. These test photos are all at f 5.6, and I think would be somewhat sharper at f 8.0 and beyond.

In case the EXIF is skimpy, these were all taken in AV mode, f 5.6 and ISO 800. Shutter speeds seem to be between 1/15 and up to 1/60 and maybe some a little faster. None of these have any post processing, not even cropping, all JPEGs right out of the K-1. They were taken using umbrella in one hand and camera in the other, so the SR may have gotten a nice workout!

---------- Post added 10-23-17 at 06:19 PM ----------

I see a few of those around but they are more expensive than the 67 one ($37). Just wondering if you had a link to a truly cheap one.

67 to K mount, $19.15: jiakgong on eBay
645 to K mount, $36.15: wyhking007 on eBay

Hope this helps.

[mattb123]

[/COLOR]
67 to K mount, $19.15: jiakgong on eBay
645 to K mount, $36.15: wyhking007 on eBay

Hope this helps.

Ok thanks! That is about what I was finding. Just wanted to be sure I wasn't overlooking a much better deal.

[Fcsnt54]

I agree. I have two of those 135LS lenses, and use as LS lens on the 645D and as a standard lens on the K-1. I have only used it once on the K-1, but definitely found it to be an excellent, sharp lens, and I plan to use it more in the future. I also have the 75LS, and have also used it on the K-1 as a standard lens. So far as I am aware, there is no way to use either the 75LS or the 135LS as LS lenses on the K-1.

---------- Post added 10-23-17 at 02:44 PM ----------


Good to hear from you. You can get a cheap Chinese P67 to K adapter for about $7-10. I see no point to paying the big bucks for a genuine Pentax adapter, since it is mechanical only and does not provide any form of communication with the camera.

Yeah I agree, Not really aware of a way to utilize the LS Portion of the lenses on the K-1 either. Then again I haven't used that feature on the 645z, beautiful lenses though and very easy to focus with. I might take them for a spin this week.

[ivanvernon]

Ok thanks! That is about what I was finding. Just wanted to be sure I wasn't overlooking a much better deal.

The prices were not quite as low as I had remembered once I went back to eBay and checked on the actual purchases--still cheap compared to the Pentax versions, however.

[ivanvernon]

Here are five test shots taken in early morning light to demonstrate use of Pentax 67 55mm on the K-1. This is a big heavy lens that is worth carrying around. Color rendering is great, and it shows great clarity/sharpness. I like it for my flower photography because it focusses at a minimum distance of about four inches, so that fairly small flowers can still fill the frame. I almost always use this lens using AV mode because it does not require using the green button. Focussing is easy, and I use the focus light in the viewfinder and listen for the beep.

[ivanvernon]

Here are a few snaps around the house--takes a little thought to use the 67/200mm, especially when its FOV is even narrower on the K-1, equivalent to that of a 320mm full frame lens. This is a well-rated lens in terms of image quality, and an inexpensive way to achieve telephoto lens FOV if you don't need auto focus.