Monster Adapter LA-KE1 Pentax K to Sony E Lens Adapter

Unexpected Behaviors

In the vast majority of cases and scenarios, the LA-KE1 adapter with firmware v03 performs just as it should, without quirks.

There are still some tiny events which occur from time to time and are worth mentioning.

EXIF Errors

When reviewing files in Lightroom, we encountered two types of errors.

The first concerns lenses with variable aperture, such as D FA 28-105mm. When shooting at medium to long focal lengths, using the fastest aperture available (for instance, F5.6 at 105mm), the adapter assumes that the aperture is the lens's fastest aperture, F3.5 in this case:

Another case occurred with the DA* 60-250mm, specifically when using focus mode 1 (forced screw-drive). The lens's fastest aperture is reported as "F4.1":

These two occurrences do not impact operation. The second has no practical impact, whereas the first cripples the documentation a bit (but it is easy to guess the actual true aperture).

Resetting the Adapter

The adapter can be reset simply by disconnecting it from the camera, even partially. Otherwise, even if the camera is turned off, the adapter is not "reset".

When changing lenses, our experience strongly suggests that the adapter should be reset. Refraining from doing so will often lead to erratic autofocus behavior. The solution is simple and should be executed as a preventive measure at all times.

Battery Drain

With prior versions of the firmware, some users reported some battery drain even when the camera was turned off. This is not something we were able to reproduce and measure with our unit and firmware v03, however good practice might be to partially unmount then remount the adapter when turning the camera off. Simply resetting as explained above is sufficient.

Removing the Adapter

We have read of one single occurrence of a Monster Adapter, Nikon model, which fried the camera when it was removed with the camera powered on. This occurred with an early firmware version. We obviously did not try to duplicate this, and have failed to read of other such occurrences, but users would be well advised to turn off their camera before mounting or unmounting their adapters. This is good practice with lenses also.

Other Observations

A few users have reported other quirks, such as having trouble updating firmware or observing erratic focus behavior. No such events were observed during our tests. They are still possible, if probably rare. Of course, we were not able to test all 64 supported lenses and cannot confidently claim any opinion on the bahavior of lenses we have not tested.