Installing and Operating the Digital SLR Adapter for Operating Microscopes
Richard J Kinch
Updated: October, 2014
- Identify the following kit contents:
- The diagonal adapter, with instrument fitting and camera fitting.
- Setscrew (M4x0.7-4) and hex key (2mm) for locking a semi-permanent orientation.
- Hex key (1.5mm) for adjusting DSLR bayonet orientation.
(This is included only for configurations using hex-socket setscrews, and not included
for slotted-head setscrews.)
- A printed copy of these instructions.
- Remove any conventional lens, body cap, or other attachment from the SLR camera, leaving just the lensless SLR camera body.
- Observe that the adapter provides a fitting to mate with the instrument beamsplitter on one end, and a camera bayonet fitting on the other.
- Take care when handling the loose adapter not to touch the lens surface inside the instrument fitting.
- Remove any cap from the adapter bayonet fitting.
- Attach the camera body to the adapter bayonet fitting.
- Attach the camera with adapter to the instrument beamsplitter fitting.
- Choose an adapter orientation.
You may configure the adapter to various orientations by loosening and rotating the fittings on each end of the adapter.
The most commonly desired orientations are: (1) The adapter turns horizontally to the rear toward the observer, with the camera upright, and (2)
The adapter turns vertically upward to avoid the observer, with the camera rotated 90 degrees so the image is upright.
The new adapter will ordinarily be supplied in orientation (1) from its original manufacture and test.
- Adjust the adapter orientation, if you so desire,
by loosening the setscrew and rotating the instrument attachment, so as to turn the adapter to the desired direction.
- After rotating the instrument fitting, to bring the camera image to the normal upright position,
slightly loosen the three small setscrews in the bayonet fitting, rotate the camera, and retighten the setscrews.
Fastening these setscrews may require either a flat-bladed screwdriver or hex key, depending on the camera type.
- Configure the camera for manual operation ("M" setting on the mode dial).
The microscope with adapter is in effect a manual lens for the camera.
Hence the aperture and focus settings in the camera will be unavailable.
Use the camera's ISO speed setting and manual shutter speed to obtain a proper exposure.
- Calibrate the focus of the instrument to the camera focus as follows:
- Obtain an image visually in the instrument binocular.
Adjust the eyepiece diopter settings for any refraction error in the viewer's eyesight.
Bring the view to a sharp focus through the instrument eyepieces.
- Obtain a live camera image.
- Focus the camera image by loosening the thumbscrew and moving the attachment slightly in or out, and locking the thumbscrew.
Thus the camera will be parfocal with the eyepiece view. That is, when the view through the instrument eyepieces is in focus,
the camera should also be in focus.
The shoulder of the attachment barrel, as held by the thumbscrew, should be flush, or nearly so, with the end of the receptacle.
- Use the camera's digital zoom feature with the live view to see a more precise view of the camera focus.
- To semi-permanently lock the orientation and parfocality, replace the thumbscrew with the supplied set screw (M4x0.7-4) and tighten with the
supplied hex key (2mm). The brass collar inside the receptacle should remain between the setscrew and aluminum fitting.
- The cropping of the circular field of view of the eyepieces into the 4:3 rectangular field of the view in the camera will depend on the
relative focal lengths of the binocular and adapter, the field number of the eyepieces, and the camera's sensor size.
A typical cropping goal is to have the full width of the eyepiece view in the camera frame, with a small portion of
the top and bottom of the eyepiece view cropped out. This fills the corners of the camera frame with portions of the image which are not
normally seen in the eyepieces. Unlike the eyepiece view, you will not see the circular field stop in the camera viewfinder or images.
- To enlarge the image in the camera (that is, to "tighten" the crop), use an extender such as (for Canon DSLRs) the Canon Extender EF 1.4x or 2.0x,
or (for Nikon DSLRs) the Nikon TC-14E II 1.4x or Nikon TC-20E III 2x teleconverters (etc.).