3D-Printed Adapter for ZWO ASI120 to Lacerta OAG and Canon 650D

Lacerta makes a very low-profile off-axis guider with an M48 thread on one side, and a Canon EF bayonet on the other side. It is reasonably well-made, but the (used) one that I bought had some pretty serious grub screw markings on the guide camera pick-off tube due to over-tightening of the setscrews that hold the guide camera T-mount to the pick-off tube.

I can see why the previous owner did this: if the setscrews aren't tight, the guide camera can rotate, particularly if the guide camera's USB cable gets snagged on something.

I decided to 3D-print an adapter that would screw into the M4 threaded holes on the back of the ZWO ASI120 guide/planetary camera, and which in turn would hold the camera at the right distance to achieve focus, and bolt to the 1/4" 20tpi tripod socket on the Canon EOS650D DSLR.

It's a very simple design, and would need to be modified for any other guide camera and potentially DSLR, since the sizes are different and the focal points are also different. In this case, I'm using a William-Optics Flat6A flattener/reducer, with its native M48 interface at the rear.

The design is here.

An added bonus is that the 3D-printed adapter also helps to protect the guide camera and OAG from mishandling. Without the adapter/reinforcement, imaging what would happen if you dropped the DSLR: the pick-off tube on the OAG would most likely get bent out of shape.

And here are a few photos:






ProLink PIC3002WN Review

This is a discontinued IP camera from ProLink (https://prolink2u.com/product/pic-3002wn/). There is another review here but otherwise not much additional information.

I bought four of these for home surveillance, but have discovered a number of shortcomings which you need to consider when buying these::
  • the iOS client hard-resets my iPhone 7 Plus randomly, although my wife's iPhone 8 is "fairly" stable
  • only SD card and DropBox recording work, when recording to a NAS (Windows share) the recording randomly stops. Dropbox requires a paid Dropbox account since the number of files is quite large, and you would also need a lot of bandwidth; a day of recording is about 3GB
  • there is no FTP recording, contradicting the review linked above

  • the cameras sometimes randomly lose their recording settings
  • there are days and days with no available recordings, because the cameras stop recording after a couple days; therefore you have to power-cycle them every few days
These cameras are cheap, and in principle have a lot of features. The video quality is reasonably OK, the IR mode works fine, but unless you use the SD card or DropBox recording, the "added" features are unreliable.  And even if using SD card or DropBox, you have to reboot them every couple days otherwise they stop recording entirely.

50mm on Full Frame Test

This is a contrived test of center and corner sharpness of various 50mm lenses, SLR and rangefinder. I decided to compare the performance of my 1938 Leitz Summar before selling it. The test was fairly simple: I took two pictures of a Schneider wooden cuckoo clock, one at the center of the frame, and one at the edge (but not corner). All photos were taken on a Sony A7-II, with IBIS enabled, and manual focus using the zoom-in button. Distance was about 3 meters (typical portrait or half-body distance) and all lenses were wide-open to maximize aberrations.

Here's the clock face at the center of the image (rotated 90 degrees for convenience):

And here is the same clock face at the edge of the image (also rotated 90 degrees):

And here are the center images:

Canon 50mm f/1.8 LTM

Industar-61LZ 55mm f/2.8

Jupiter-3 50mm f/1.5 Sonnar copy

Jupiter-8 50mm f/2 Sonnar copy

Carl Zeiss Jena Pancolar 50mm f/1.8

Contax Carl Zeiss Planar 50mm f/1.7

Canon 50mm f/1.8 STM

Ernst Leitz Wetzlar 50mm f/2 Summar (1938)

Pentax Super-Takumar 55mm f/1.8

Pentax Super-Takumar 50mm f/1.4 (7-element)

And the edge images:
Canon 50mm f/1.8 LTM

Industar-61LZ 55mm f/2.8

Jupiter-3 50mm f/1.5 Sonnar copy

Jupiter-8 50mm f/2 Sonnar copy

Carl Zeiss Jena Pancolar 50mm f/1.8

Contax Carl Zeiss Planar 50mm f/1.7

Canon 50mm f/1.8 STM

Ernst Leitz Wetzlar 50mm f/2 Summar (1938)

Pentax Super-Takumar 55mm f/1.8

Pentax Super-Takumar 50mm f/1.4 (7-element)