Bresser MikrOkular camera

Successfully attaching two different Bresser microscope cameras to Zeiss IM microscope and having both in focus with eyepieces on trinocular head

It has taken a while to get here but at last I have been successful!

Using second hand Diagnostic Instruments Adapters, I have now attached two separate cameras simultaneously to my Zeiss IM microscope. The advantage of this setup is that the Bresser MikrOkular camera (1.3 megapixel – HD definition) is brilliant for video, giving a smooth result at a decent resolution. The chip is quite small so I am using the 0.7x Diagnostic Instruments adapter to reduce this magnification factor that results from this – the end result is still more magnified that the 5 megapixel Bresser Mikrocam 5.1 camera produces in the Diagnostic Instruments 1.0x adapter.

The 5 megapixel Bresser Mikrocam 5.1 camera produces in the Diagnostic Instruments 1.0x adapter is attached to the second port on the Zeiss 910137 dual head block I have attached between trinocular head and IM base (horizontally in the photos below). The Bresser MikrOkular camera on 0.7x Diagnostic Instruments adapter is attached to the camera port on the trinocular head (vertically in the photos below).

The Diagnostic Instruments adapters have inbuilt focusing rings that allow both cameras to be bought into focus with the eyepieces. As the MikrOkular camera does not have a C-mount attachment, I have had to use a combination of adapters to attach this to the Diagnostic Instruments adapter. The MikrOkular camera fits into a 1.25 inch to 2 inch telescope eyepiece adapter, which itself slots into a 2 inch to T-mount adapter. I then use a male T-mount to female C-mount adapter to allow this to be attached to the Diagnostic Instruments adapter.

I have uploaded below pictures of the setup plus photos of Seed of Castor sec (commercial slide) observed using a 32x objective. Those photos are taken without changing focus setting so demonstrate the difference in magnification scale between the two cameras.


Mikrocam 5.1 camera (horizontal) and MikrOkular camera (vertical) (below):

Seed-of-castor-sec-Zeiss-IM-32x-Bresser-Mikrocam-5-1-030218.png (below):

Seed-of-castor-sec-Zeiss-IM-32x-Bresser-MikrOkular-030218.png (below):

Diatom photos processed using Helicon focus 6 from Stowe Pool jar culture 20/1/2018

Here are some diatom photos I processed today using Helicon Focus 6 – the pictures are either combined across 20-26 sub-frames or 3D models produced from that data.

All on Zeiss IM microscope with Bresser MikrOkular camera.

Preparation for photography of these samples included 20ml pipette in jar – 5ml formalin 10% added to kill specimens so that they don’t move during photography – important when taking pictures at different focus distances. Helicon does not really work on live specimens!


Diatom as in life:

Combined frame – great views of organelles. Note also the large number of bacteria in the slide (small dark rods):

Depth map:

3D model:

Empty Diatom Skeleton:

Combined frame – shows segmentation of diatom skeleton well:

3D model:

Diatom skeletons and Volvox (green circles in middle):

Combined frame:

Following are variations on above using different settings for smoothing and radius in Helicon Focus – variously brings out more or less the foreground diatom skeleton that goes from top to bottom just to right of Volvox:

3D Models:

Determining magnification for photographs taken with Bresser MikrOkular camera through Zeiss IM microscope

Rhys and I used a calibration slide to determine the on-screen magnification of images taken through the Zeiss IM microscope with different objectives using Bresser MikrOkular camera.

6×0.01mm horizontally = 0.06mm
4.5×0.01mm vertically = 0.045mm.
On my laptop (Dell M4800) one of my photos through the MikrOkular appears at 290mmx170mm in size.
Hence the magnification in this image = 290/0.06 = 4833 x magnification (calculated on basis horizontal size)
Or 170/0.045 = 3778 x magnification (calculation on basis vertical size).
The difference is probably explained by either unequal pixel sizes on screen or part photo cut off (probably vertically) on screen.
Taking an averge magnification = (4833+3778)/2 = 4300x magnification
Hence magnifications using MikrOkular camera are:
(i) 4x objective = 273x
(ii) 10x objective = 680x
(iii) 20x objective = 1360x
(iv) 32x objective = 2180x
(v) 40x objective = 2730x
(vi) 63x objective = 4300x

For future posts, the magnification using MikrOkular camera can be calculated using a magnification factor = Magnification calculated as MikrOkular camera & screen magnification factor 68 (=4300/63). To calculate magnification = magnification factor x objective magnification. For example, for 32x objective with MikrOkular camera, on screen magnification will be 68×32=2176 (approx).

Andy & Rhys

Calibration images taken using 63x objective – the lines are 0.01mm apart from each other: