[jco]

Has anyone tried using the vintage SMCK 18mm f3.5 lens in full frame mode on the K-1?
What were your general impressions and could you post some large sample images?
Thanks in advance.

[monochrome]

Hi John: I have used the lens on film. I’ll do some on K-1 for you tomorrow.

[jco]

I really like it on digital so far, but I only have a crop sensor istDS.

[Adam]

Has anyone tried using the vintage SMCK 18mm f3.5 lens in full frame mode on the K-1?
What were your general impressions and could you post some large sample images?
Thanks in advance.

It's a full frame lens and certainly covers the whole image circle. I picked up one of these lenses a few years ago to complete my collection.

Unfortunately it's pretty far behind modern glass when it comes to sharpness and aberrations, but it's a fun little lens nevertheless. However, I'll be sticking to my D FA's for daily shooting.

Here's a sample shot with the focus on the zoo sign. Notice how the distant objects near the left/right third of the image become soft:
https://themotec1.netfirms.com/Users/Hosted/cdn/k1/samplephotos/IMGP0361.JPG

Adam
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[jco]

It's a full frame lens and certainly covers the whole image circle. I picked up one of these lenses a few years ago to complete my collection.

Unfortunately it's pretty far behind modern glass when it comes to sharpness, aberrations, and even vignetting, but it's a fun little lens nevertheless. However, I'll be sticking to my D FA's for daily shooting.

Too bad they don't make a D FA 18mm prime. that would be nice.

[Adam]

Too bad they don't make a D FA 18mm prime. that would be nice.

I know there's a wide prime on the roadmap- perhaps we'll get something along those lines!

Until then there's the Irix 15mm, which is quite a bit wider, but good overall:
Irix 15mm F2.4 Firefly & Blackstone Review - Introduction | PentaxForums.com Reviews

[baro-nite]

Here's a recent one, uncropped:



As you can see, the corners aren't great. There's also barrel distortion, not that you can tell from this subject. Bearing those issues in mind I think it is still a good performer, and one I enjoy using.

[pschlute]

What were your general impressions and could you post some large sample images?

Here is an image I took with that lens on the K1. It has been resampled. My impression is that the lens is sharp enough in the centre, and the PF is not too bad considering its age.

[jco]

It's a full frame lens and certainly covers the whole image circle. I picked up one of these lenses a few years ago to complete my collection.

Unfortunately it's pretty far behind modern glass when it comes to sharpness and aberrations, but it's a fun little lens nevertheless. However, I'll be sticking to my D FA's for daily shooting.

Here's a sample shot with the focus on the zoo sign. Notice how the distant objects near the left/right third of the image become soft:
https://themotec1.netfirms.com/Users/Hosted/cdn/k1/samplephotos/IMGP0361.JPG

That looks pretty bad. Was it shot wide open or what? While obviously not as wide, my copy looks much better at f8 on a crop sensor.
https://www.jchriso.com/temp/061814b.jpg

---------- Post added 07-27-2018 at 11:42 PM ----------

Here is an image I took with that lens on the K1. It has been resampled. My impression is that the lens is sharp enough in the centre, and the PF is not too bad considering its age.

what is "pf"?

[pschlute]

what is "pf"?

Purple fringing, a form of chromatic aberration. Noticeable where the tree branches meet the sky behind.

ps. just to be clear, in my image the people and background are meant to be soft.

[jco]

Purple fringing, a form of chromatic aberration. Noticeable where the tree branches meet the sky behind.

ps. just to be clear, in my image the people and background are meant to be soft.

oh, yes, my copy has just a very little CA near the edges.

[Ronald Oakes]

I don't have any images to show. However when I was on a hunt for the SMC-K 20mm I ran across this one and tried it for about 2 weeks.
Long story short....I simply didn't like it much after acquiring the 20mm and doing a comparison and quickly ditched the 18.
I disliked it more than any SMC-K series lens from Pentax that I ever used.
Mine was un-sharp in the center edges even stopped down , and the distortion seemed rather strange.

[jco]

Here is an image I took with that lens on the K1. It has been resampled. My impression is that the lens is sharp enough in the centre, and the PF is not too bad considering its age.

That seems pretty sharp even two thirds of the way out on the subject. And yes I can tell you focused on the close foreground putting all the background slightly out of focus.

[Ronald Oakes]

Too bad they don't make a D FA 18mm prime. that would be nice.

Even a D FA 20mm would be nice.

[jco]

Hi John: I have used the lens on film. I’ll do some on K-1 for you tomorrow.

Thanks

---------- Post added 07-28-2018 at 12:44 AM ----------

I don't have any images to show. However when I was on a hunt for the SMC-K 20mm I ran across this one and tried it for about 2 weeks.
Long story short....I simply didn't like it much after acquiring the 20mm and doing a comparison and quickly ditched the 18.
I disliked it more than any SMC-K series lens from Pentax that I ever used.
Mine was un-sharp in the center edges even stopped down , and the distortion seemed rather strange.

was this finding on film, crop digital, or full frame digital?