[Benz3ne]

I've some M lenses I use on the K-1 and they perform well. It doesn't take much effort to get into the habit of tapping the green button for metering. The metering seems to be pretty accurate too, which is nice.

[Jean Poitiers]

I use a lot of manual lenses ... because I really like them and have plenty to play with ... M, K, A, M42 Taks plus other brand M42, etc.

[Lowell Goudge]

I guess I was thinking initially of the functionality aspect, what the experience of using K and M lenses on the K-1 is actually like. I'm pretty familiar with the look of vintage glass on FF digital in the general sense and like how it works out.

The biggest issue, for me is the lack of flash support. Unless you shoot with A series or later, you give up on through the lens metering (TTL). Since the *istD series Pentax has dropped dual flash support and shifted to only P-TTL that requires to know the native and stop down aperture values for a lens. The Pentax system , like both Nokia and canon, use a pre flash With the lens wide open, to measure the flash vs ambient ratio and then with then calculates the flash needed for the exposure settings based upon the flash GN and set iso, shutter and aperture. While this stops the issue of overexposure in some blended lighting situations, I find the preflash drains the flash batteries much faster, and disturbed wild life much more than classical ttl metering. I wish the flagship lines offered both systems.

[HDpotato]

Big fan of old glass here.
K 28mm 3.5

By far one of my favorite Takumars (mine is an M42) - I'm waiting for the 30120 adapter to come in the mail, can't wait to try it out on the K-1 Mk2, which is my first FF camera, and Pentax camera.

I've been shooting it on Fuji bodies and love the close focus distance and the possibility to create images with short DoF and plenty of environment due to the wide angle.

[ivki_com]

I've recently got back into Pentax via a LX and a group of K and M lenses that came my way. I've been shooting Nikon film (for decades) and full-frame digital (for several years) and using my manual focus glass is pretty much the same experience in both instances. I'm wondering how well the older manual focus K mount lenses work out on full frame Pentax?

both the K and M versions are still good on the K1. But our "fast" time requires fast autofocus
Manual - now the lot of leisurely thoughtful shooting

[jab2980]

The K 135 2.5 was an absolute dream on my K-1. Others like the K 55 1.8 do well but none stand out to me like the 135 does.

[John Shriver]

Don't expect to focus manual-focus lenses with shallow DOF (50/1.2, 200/2.8, etc.) accurately with the focusing screen, even with the eyepiece magnifier. The bright screen just can't focus them. You will need to use the auto-focus "trap" feature.

While there are modified Canon screens you can put in the K-1, they will mess up the light metering badly. (I tried.)

[Racer X 69]

I don’t have any K series lenses, but do have quite a few M series, as well as A series, and some M42 glass.

They all have potential for producing excellent images on the K-1.

[jcdoss]

...While there are modified Canon screens you can put in the K-1, they will mess up the light metering badly. (I tried.)

I'm using modified S-type Canon screens from focusing screens.com in both my K-1 mIIs and I don't find the metering messed up. What problems were you seeing?

[Racer X 69]

Don't expect to focus manual-focus lenses with shallow DOF (50/1.2, 200/2.8, etc.) accurately with the focusing screen, even with the eyepiece magnifier. The bright screen just can't focus them. You will need to use the auto-focus "trap" feature.

While there are modified Canon screens you can put in the K-1, they will mess up the light metering badly. (I tried.)

I’m using an unmodified K-1. This image was made using a Sigma 135mm f2.8 Pantel lens. It was exposed at f8, 1/250th sec, ISO 100, hand held, composed and focused through the viewfinder.



I think the focus is perfect, I certainly got the results I was looking for.

[pres589]

At f8 you could basically focus using the focusing scale on the lens and come out alright. f2 or faster is when it becomes more challenging though obviously still possible.

[Racer X 69]

At f8 you could basically focus using the focusing scale on the lens and come out alright. f2 or faster is when it becomes more challenging though obviously still possible.

I suppose.

But I composed, evaluated the focus and exposure settings, entirely through the viewfinder. The only time I wasn’t using the viewfinder exclusively was when I had to “zoom” with my feet to get the subject framed as I desired. The aperture wound up at f8 as a result of the adjustments I made to get the image I was looking for, first focusing, then adjusting the f stop and shutter speed to make the correct exposure.

I usually focus with manual lenses wide open, and this lens has a maximum aperture of f2.8, so not quite f2 or wider, but a long ways from the f8 the exposure was made at.

I do find a 600mm mirror lens I have is difficult, if not impossible, to get focused at all on digital cameras. Even when I get what looks like a well focused image, pixel peeping proves otherwise.