[andrewd]

I own LX, KX and MX and some of the consumer grade stuff (ME, P30 etc). The three X cameras are in another league to the rest.

For me the most robust award easily goes to the KX. The LX is mechanically robust but electronically fragile. The KX is perfectly balanced with just the right amount of heft without being a boat anchor like a Nikon F2. The shutter/mirror is beautifully damped, perhaps better than any other mechanical SLR I own. The Nikkormat FT2 comes close. I actually prefer the size of the KX to the MX, which pushed the minituarisation fad a bit too far IMO. However for me the KX is let down by a relatively dim and difficult to focus viewfinder..

So therefore, my favourite K mount body is……..






MX.
Due to the wonderful high magnification finder, smooth mechanical operation, intuitive meter interface and classic old school looks.

[rvandenbrink]

KX and K1000’s for sure. If the meter works, the camera is almost always good. Worst case new seals and they’re ready to shoot

[TwoUptons]

I love shooting with my MX, but they seem more fragile than the KX/KM/K1000

A good overhaul for any of them, though, should see you for a couple more decades...

-Eric

[ChrisPlatt]

I recommend the simple and robust Pentax KM.
The K1000 has even less to break.

Chris

[Autonerd]

My vote goes to the MX but I do not have any knowledge or insights to support it.

I thought the MXs were prone to shutter problems? Certainly seems that a lot of owners have issues with shutters (including me).

My KX has been running for 40-odd years (albeit with a two-decade break 1999-2019) and still works just fine with a good meter and shutter timing. BUT -- if I were going to guess at the most robust, I'd say the KM. Less features to break than the KX and K2, and didn't suffer the "decontenting" of the K1000.

Aaron

[andrewd]

I thought the MXs were prone to shutter problems? Certainly seems that a lot of owners have issues with shutters (including me).

My KX has been running for 40-odd years (albeit with a two-decade break 1999-2019) and still works just fine with a good meter and shutter timing. BUT -- if I were going to guess at the most robust, I'd say the KM. Less features to break than the KX and K2, and didn't suffer the "decontenting" of the K1000.

Aaron

I am curious to know what shutter problems you have on your MX? Is it erratic high speeds? Do you have an early or late model MX? My late model MX is fine, but it has been professionally serviced and is a sample size of one.

The Harrow site indicates erratic high speeds as a problem with early MX’s as well as a stiff film advance mechanism. I trust this site for researching common problems with pentax cameras since it is based on decades of experience servicing these cameras.

[Autonerd]

I am curious to know what shutter problems you have on your MX? Is it erratic high speeds? Do you have an early or late model MX?

I can't remember and I don't know. I think one shutter curtain was hanging up -- I honestly don't remember. Had it repaired by the local guy rather than a Pentax expert, btw.

How do I tell late from early production?

Aaron

[nicolpa47]

I can't remember and I don't know. I think one shutter curtain was hanging up -- I honestly don't remember. Had it repaired by the local guy rather than a Pentax expert, btw.

How do I tell late from early production?

Aaron

I read somewhere that the early MXs had a metal holder for the "end of film box" reminder on the camera back. The later versions were plastic.

[Billy Bokeh]

While I find the earlier screw mount Spotmatics to be incredibly reliable, “Hammer of Thor” quality chunks of metal, and often in great working condition, the K mount related cameras like the KM, KX, early and mid production K1000 and K1000SE are pretty good cameras very similar to the earlier screw mount Spotmatics- typically I find them with minor issues like a corroded or detached light meter wire, or occasionally a sticky mirror or timer. Really not bad for cameras stretching back to the mid 70’s, and with a CLA service and new light seals and mirror bumper, I expect to get 20-30 more years out of them.

The MX is also a great camera- but I do find acquired used examples to have more dings and dents on their casing then the larger and heavier cameras that came before them, and niggling gremlins with the light meter system, aperture “Judas window”, shutter speed inner wheel, upper and/or lower speeds, curtain action, and shutter trigger. I’m wondering if the effort to make it more compact may have something to do with this. Still a stellar camera though and very recommended.

The above are mechanical cameras and seem to hold up well but I have noticed some mild variance in initial factory performance (metering accuracy with the KM, KX, K1000 and shutter accuracy) with age.

The electronic ME Supers I pick up can suffer from winding issues and mirror hangup issues but this is serviceable- a repaired and CLA’d ME Super is a great little camera and a treat to use. They sometimes have an inoperable or wonky light meter, but for every one I got my hands on, it was down to the ASA/ISO/Exposure compensation switch being dirty, having a buildup on the contacts. Once the contacts are cleaned and/or exercised back and forth, the meter has worked flawlessly afterwards- and the camera’s light meter and shutter speed of these hasn’t seemed to have wandered over the years.

I have others here but the ME Super, MX and KM (and Spotmatics) are my preferred Pentax cameras for their build quality and usability. I would add the KX but as a lefty/left eye camera user with glasses, the quirk of the KX meter lever needing to be out away from the body to operate isn’t an ideal fit.

[andrewd]

I suspect the metal body parts on the M series cameras are thinner than the K series cameras in order to minimise weight. Has anyone who has pulled the cameras apart confirmed this? The MX still does feel very nicely made, but I would be picky when choosing one. A good tip is to look for one that includes an eveready case. This usually means the owner was an amateur photographer that cared about keeping the camera in good condition.

The problem of a loose mirror in the Judas window is common to all of the Pentax cameras that had this feature. An easy fix when getting the camera serviced, but obviously the cost of the service needs to be factored in (usually as much as the purchase cost of the camera).

[UncleVanya]

Why is it called a Judas Mirror?

[JoeUrban]

Why is it called a Judas Mirror?

Some discussion here
Etymology: "judas window" in film camera - PentaxForums.com