Step 2: Take Measurements

Picture of Take Measurements
We need 3 basic measurements before we can create a 3D model.

Camera Mount (adapter base)
Measures the lens that came with your camera (see image below for details on this measurement). Be sure to first measure the diameter excluding the three tabs. To do this place your calipers just inside two of the tabs and write down the nubmer. Then grab the lens that came with your camera and measure the small tabs Lenght x Weight x Height of one tab and then the distance to the next tab.  It may help to sketch this out on paper.  You might be able to find some lens measurements on this chart  or you can see if an model exists in Google’s 3D warehouse.

Lens Mount (Lens you'll attach to the adapter)
Again follow the images below to take measurements of lens that you'll be attaching to your adapter. Depending on how secure you want your lens to attach depends on the details of this measurement. I was able to get away with a simple measurement of the diameter of the Nikon e mount and was able to make sure the 3D print would be a simple press fit. (it does not lock in place, it simply presses in place instead)

Focal Distance 
Once you have selected your lens it’s time to figure out which distance it needs to be away from your camera sensor to make clear images. 

Warning: Always be aware that removing your lens exposes your sensor to dust which could stick to your sensor and mess things up. So, be very careful with this next part and try to be in a room with little to no air movement i.e. fans, windows, a/c.

Remove your existing lens from your camera body, then hold up the body and newly purchased lens until the image comes into focus (see images below). This is by no means an exact science but here are some time saving tips. Open your aperture on your lens all the way. In this case I opened mine to 1.8. Use a tripod so you can use your free hand to adjust or measure the final distance once things look in focus. You can also use a toilet paper roll during this step to help judge distance by holding the roll as a makeshift temporary adaptor, slowing cutting off sections of the roll to make it shorter and shorter until you find the correct distance. Once you have a pretty good idea of the distance from body mount to the lens, write it down and head to the computer to draw things up.

Degree of tilt
This is up for experimentation but my current model is using somewhere between a 5 and 20 degree tilt. I seem to get the best results and most range with a 10-12 degree tilt, so try that a starting point.  Here is a guide which will help you establish the perfect tilt.