Is your camera actually a 5D, rather than D5?
If a 5D, those have been produced in several versions.
For microphotography, what Canon calls "Live View" is wanted.
- focus directly on the sensor
- avoid SLR mirror slap vibrations
- HDMI for larger external display
"Live View" was unavailable on the original 5D, being introduced on the Mark II:
https://en.wikipedia.org/wiki/Canon_EOS_5D_Mark_II
https://support.usa.canon.com/kb/index? ... =ART170202
The Leica DMLB seems to be a capable and fairly recent microscope,
consequently relatively rare for hobbyists, but already discussed here:
viewtopic.php?f=25&t=14148
Two ways of photographing with a binocular head:
- afocal: positioning a camera with lens over the eyepiece,
often done with compact cameras and smartphones
- projection directly from ocular to camera sensor, with its normal lens removed.
Ideally, the conventional ocular is replaced by a matching PHOTO ocular, as described on page 29:
https://cdn.shopify.com/s/files/1/2090/ ... a_dmlm.pdf
For older microscopes, where ocular dimensions were more standardized,
T-mount adapters were made to either slide into or fit around eyepiece tubes;
searching e.g. eBay for "T mount microscope" will show a variety of adapters.
For attaching a T (or T2) thread to a Canon EF body, search for "M42 focus confirm EOS"
M42 is not exactly the same as T (or T2) thread, but is often 'close enough'.
Many T2 adapters are advertised as T-thread; the difference being that T2
has provisions for rotating the camera body to a desired orientation when 42mm threads are fully tight.
Extension tubes and perhaps an M42 helicoid will get proper spacing between ocular and camera sensor.
To actually support a camera's weight in stable orientation over an binocular eyetube,
when a strong adapter with precisely matching dimensions is unavailable, improvisation is wanted.
Either a copy stand or old enlarger stand can be adapted for a tripod mount,
and a macro focus rail will help stably adjust the camera's positioning.
Measure the binocular eyetube's outer diameter; if less than 42mm,
then some combination of step-down rings can be ordered
to obtain a close fit between extension tubes, M42 and eyetube,
with an O-ring tight around that eyetube to block light leakage.
When a matching photo/projection ocular is unavailable,
photographic results can be improved by focus stacking.
For many Canon DSLRs where focus bracketing is not officially supported,
it can be added using Magic Lantern:
https://magiclantern.fm/
which only works when an autofocus lens is attached, so afocal.