[pinholecam]

For those who

This is definitely not the typical review! I appreciate and admire the long term approach you've taken with this.

For those like me who've been holding out, I just noticed the adapter is on sale right now at B&H and Adorama. Be sure to use the forum's affiliate links if you buy!

Do you buy from Adorama or B&H Photo? (Support PentaxForums!) - PentaxForums.com

Glad that you find the review useful.
Thats what the forums is for.

[LaurenOE]

This should be fun. I am getting this adapter and the new A7RV on about the same day. I will try this adapter with the Sigma 300mm F2.8. Hows that for a weird combination!?!

[luftfluss]

This should be fun. I am getting this adapter and the new A7RV on about the same day. I will try this adapter with the Sigma 300mm F2.8. Hows that for a weird combination!?!

That *is* highly unusual!

Nice to see a post from you!

[LaurenOE]

That *is* highly unusual!

Nice to see a post from you!

Yeah, I'm still here, and a Pentaxian, but hard to take my Pentaxes out with so much Sony gear these days. I think some of my larger legacy glass will find its way onto the marketplace soon...as much as that pains me. Maybe its time to let go of some stuff.

[UncleVanya]

This should be fun. I am getting this adapter and the new A7RV on about the same day. I will try this adapter with the Sigma 300mm F2.8. Hows that for a weird combination!?!

It most likely won’t work in autofocus and it likely won’t stop down. The adapter is limited to use on the names lenses only - all of which are Pentax branded. It functions weirdly on lenses that are similar but not identical to the names lenses. For example the F 50/1.7 won’t work but the FA 50/1.4 does. It’s been explained to me by the designer that each lens model must be profiled and setup in the adapter to lie to the camera.

https://www.monsteradapter.com/products/la-ke1-pentax-k-mount-lenses-to-sony...ameras-adapter

[LaurenOE]

It most likely won’t work in autofocus and it likely won’t stop down. The adapter is limited to use on the names lenses only - all of which are Pentax branded. It functions weirdly on lenses that are similar but not identical to the names lenses. For example the F 50/1.7 won’t work but the FA 50/1.4 does. It’s been explained to me by the designer that each lens model must be profiled and setup in the adapter to lie to the camera.

https://www.monsteradapter.com/products/la-ke1-pentax-k-mount-lenses-to-sony...ameras-adapter

Probably then. It will be fun to try out all the other lenses on the A7R5. Should be fun!

[UncleVanya]

Probably then. It will be fun to try out all the other lenses on the A7R5. Should be fun!

It certainly can be. Here’s a shot from my DA* 55/1.4 from yesterday:

Lights! Camera! Bokeh! by -vanya_42nd-

[pinholecam]

This should be fun. I am getting this adapter and the new A7RV on about the same day. I will try this adapter with the Sigma 300mm F2.8. Hows that for a weird combination!?!

If the lens is not in the list given by Monster Adapter, then it won't work.

[KoenR]

It most likely won’t work in autofocus and it likely won’t stop down. The adapter is limited to use on the names lenses only - all of which are Pentax branded.
https://www.monsteradapter.com/products/la-ke1-pentax-k-mount-lenses-to-sony...ameras-adapter

The adapter can be used with SOME K-AF (Autofocus!) lenses of other brands but then only in manual focus mode (you can use focus peaking), however information passed from the lens to the adapter is not always correct/useful/complete.

"Works" (no AF!) in manual focus (focus peaking):
- Tamron AF Aspherical XR IF 28-200mm 1:3.8-5.6 Macro [Model A03]
- Vivitar Series 1 AF 19-35mm F3.5-4.5
Both lenses have a aperture ring, locked in the "A" position; Monster Adapter switched to "MF".
EXIF: including chosen aperture (set with camera) and focal length; "Lens Info" and "Lens Model" are empty.
Exposure: OK (sometimes slightly overexposed)
Tested on Sony A7II and Sony A6400

Does not really work:
- Sigma AF 10-20mm F/4-5.6 EX DC J
MF possible (focus peaking), but the transmitted aperture and focal length values are completely false (focal length 10mm corresponds to 2520mm..., minimum aperture F14)
Exposure: seems OK (but I did not take that many pictures)
EXIF values totally useless
Tested on Sony A6400.

Rudy

[UncleVanya]

The adapter can be used with SOME K-AF (Autofocus!) lenses of other brands but then only in manual focus mode (you can use focus peaking), however information passed from the lens to the adapter is not always correct/useful/complete.

"Works" (no AF!) in manual focus (focus peaking):
- Tamron AF Aspherical XR IF 28-200mm 1:3.8-5.6 Macro [Model A03]
- Vivitar Series 1 AF 19-35mm F3.5-4.5
Both lenses have a aperture ring, locked in the "A" position; Monster Adapter switched to "MF".
EXIF: including chosen aperture (set with camera) and focal length; "Lens Info" and "Lens Model" are empty.
Exposure: OK (sometimes slightly overexposed)
Tested on Sony A7II and Sony A6400

Does not really work:
- Sigma AF 10-20mm F/4-5.6 EX DC J
MF possible (focus peaking), but the transmitted aperture and focal length values are completely false (focal length 10mm corresponds to 2520mm..., minimum aperture F14)
Exposure: seems OK (but I did not take that many pictures)
EXIF values totally useless
Tested on Sony A6400.

Rudy

So did it stop the lens down correctly?

[KoenR]

So did it stop the lens down correctly?

I toke some pictures during a walk, but when I saw the strange aperture and focal lenght values, I stopped taking pictures with that lens. Strange enough the exposure looks ok. I will do some further tests, and check if the aperture closes. Correctly? Difficult to say as the values I could select on the camera started at F14, and then continued F16, F18, …very strange values.

[UncleVanya]

I toke some pictures during a walk, but when I saw the strange aperture and focal lenght values, I stopped taking pictures with that lens. Strange enough the exposure looks ok. I will do some further tests, and check if the aperture closes. Correctly? Difficult to say as the values I could select on the camera started at F14, and then continued F16, F18, …very strange values.

Lol. I saw some weird results like that on a lens I tried. I can’t recall which one.

[LaurenOE]

Well, I tried the adapter on the new Sony A7RV/A7R5 and the Sigma 300mm f2/8. Sadly as others have said it won't work, and it didn't. It did try a few times, and ran up the focus hunt on the lens, but no. It was not succesful. I sent a request to the Monster Adapter folks, lets see what happens over there.

So for now, my wonderful Sigma 300mm f/2.8 is not getting used unless I take out one of my Pentax cameras.

Sadly, I have become addicted to DMF mode on Sony cameras, so its rare these days to take out my Pentax cameras. So sad. I know.

[UncleVanya]

Well, I tried the adapter on the new Sony A7RV/A7R5 and the Sigma 300mm f2/8. Sadly as others have said it won't work, and it didn't. It did try a few times, and ran up the focus hunt on the lens, but no. It was not succesful. I sent a request to the Monster Adapter folks, lets see what happens over there.

So for now, my wonderful Sigma 300mm f/2.8 is not getting used unless I take out one of my Pentax cameras.

Sadly, I have become addicted to DMF mode on Sony cameras, so its rare these days to take out my Pentax cameras. So sad. I know.

What does DMF offer over say quickshift? Is it the magnified manual focus aid? I use both and DMF isn’t a thing a use a lot. I’m not certain it’s supported with the adapter.

[LaurenOE]

What does DMF offer over say quickshift? Is it the magnified manual focus aid? I use both and DMF isn’t a thing a use a lot. I’m not certain it’s supported with the adapter.

Yeah, I haven't tested everthing out with the adapter and Pentax glass, so not sure DMF works with the adapter since DMF is for Sony lenses which are fly-by-wire.

On Sony glass, yes, DMF is amazing as you can map a button to magnification while focusing all the way to what your body can support. So its amazing to get perfect focus even with the amazing autofocus of modern Sony bodies.

With modern sensors, with their resolution, its amazing to get perfect focus.

While I love my optical viewfinder, DMF function in electronic viewfinders is a game changer to get the most crisp focus you can get from a lens/body combination.