As my old mount didn't fulfill my expectations anymore I decided to get me a new mount. Main criteria where that the mount could easily handle more than one OTA in the 25cm class, that it should be portable and that it was equipped with the latest drive and GOTO systems. After some investigation I purchased the not yet in the market known "Mesu Mount". The main reason to buy this mount was that I was very closely involved in the design from the start onwards.

The mount is based on a friction drive system which is very stiff and efficient, find more info here, driven by a ServoCAT servo motor system from StellarCat (USA). For GOTO functionality StellarCat advised the sophisticated ArgoNavis GOTO controller (Australia). The mount, in this configuration, can also be controlled by a planetarium program. The mount is made by Mesu Optics (Netherlands).

Mount specifications
Drive system
Gear ratio
Meridian flip
Pointing accuracy
Periodic error
GOTO speed
Mount control
Power consumption
Friction wheels driven by Servo motors
Gearbox reduction motor = 1:60,5 and friction wheel reduction = 1:150 (1:9075 in total)
2 x 65kg
< 0,5'
± 2,0"
6 - 8 °/sec.
ArgoNavis hand controller and/or PC (planetarium program)
The mount divides in two parts of about 25kg each
Average is 400mA (when the mount guides for 90% of the time)

See here for a more detailed describtion of the mount.

The Mesu Mount


At the moment I use a 300mm f/16 Cassegrain, a 300mm f/5 Newton (both D.I.Y. projects) and a 300mm f/2,8 Nikkor lens.
The 300mm F/5 (F=1500mm) Newton, with use of the ASA corrector, will operate at F/3,7 (F=1100mm) and will be used for deepsky imaging.
The 300mm F/16 (F=5000mm) Cassegrain is based on the Takahashi CN-212 and can easily be rebuild to an 300mm F/3 Newton, exchange secondary mirror and add focusser. Currently I'll use it, in the 300mm F/16 Cassegrain configuration, for lunar and planetary photography.

Both 300mm telescopes side by side on the Mesu Mount

Correction optics

I use correction optics in order to be able to have a fully corrected field of view in my Canon DSLR and QHY10 CCD camera.

Baader Multi-Purpose Coma Corrector, click here for a test.
ASA 2" 0,73x reducer/corrector, click here for the datasheet and click here for a test.

Samyang 14 mm f/2.8 ED AS IF UMC

Optical construction:14 elements in 12 groups
Number of aperture blades:6 (non-circular)
Dimensions 78x72mm:92x86mm
Field of view:114° for FF (88° for APS-C/DX)
Min. focusing distance:0.28m
Mount:Canon (Also for Four-Thirds, Nikon, Pentax, Sony)
Filter size:no filter possible
Hood:bayonet mount

Samyang 85mm f/1.4 Aspherical IF lens

Optical construction:9 elements in 7 groups inc. 1x aspherical element
Number of aperture blades:8 (non-circular)
Dimensions 78x72mm:78x72mm
Field of view:28.5° for FF (18.9° for APS-C/DX)
Min. focusing distance:1m
Mount:Canon (Also for Four-Thirds, Nikon, Pentax, Sony)
Filter size:72mm (non-rotating)
Hood:barrel-shaped, bayonet mount
Click here for a test image with this lens

For a review of this lens click here or here.

Nikon Ai-S 300/2.8 IF-ED lens (second generation)

The 300mm f/2.8 ED-IF is what put "ED" into photography's. This ED, or super-low dispersion glass, is what allowed Nikon to create what previously was impossible, which was a fast super telephoto without sharpness-robbing chromatic aberration. Previously, secondary chromatic aberration (green/magenta color fringes on the sides and halos in the center) would have been too much of a problem with traditional lenses. IF, or internal focusing, means that you may focus simply by flicking the focus ring back and forth. The entire lens doesn't have to rack in and out. in fact, nothing moves externally.

Optical construction:8 elements in 6 groups (2 ED elements)
Number of aperture blades:9 (non-circular)
Field of view:4.5° x 3.0° for APS-C/DX
Min. focusing distance:3m
Mount:Rebuilt to T2
Filter size:No front filter, 39mm rear drop-in filter


Guide / Planetary camera's



Sensor: Micron 1/3" MT9V032 (mono) Sensor: 1/3" AR0130CS (color)
Active pixels: 752 x 480 Active pixels: 1280 x 960
Resolution: 360 Kpixels Resolution: 1.2 Mpixels
Distance T2-sensore: --mm Distance T2-sensore: 14mm
Pixels size: 6.0μm x 6.0μm Pixels size: 3.75μm x 3.75μm
Bit rate: 12bit output Bit rate: 12bit output
Frame rate: up to 55FPS max Frame rate: up to 215FPS max
Connections: USB2 and ST4 Connections: USB2 and ST4
Telescope Interface: M42/0.75 Telescope Interface: M42/0.75
Size: 64mm diameter Size: 62mm diameter

Atik383L+ CCD camera

The Atik383L+ monochrome camera

Sensor:KAF-8300 17.6mm x 13.52m
Distance sensor to T2 threat:17.5 mm
Resolution:3362 x 2504 pixels
Pixel Size:5.40μm x 5.40μm
Binning:1x1, 2x2, 4x4
ADC:16 bit
Electronic gain:2.83 e-/ADU
Readout Noise:7 e-
Power:12VDC, 2A
Exposure Length:0.2 sec - Unlimited
Guide Port:ST-4 compatible
Cooling:Regulated cooler, dT=-40℃
Weight:approx. 700 gr


Bias histogram

Cooling Curve

Small band filters

Baader H-Alpha Filter (7nm)

Baader H-Beta Filter (8nm)

Baader OIII Filter (8nm)

Hutech filters

Light Pollution Suppression (LPS-P2) Filter

Narrow-Band Nebula (LPS-V4) Filter

Modified Canon 600D DSLR

The Canon 600D DSLR

Sensor:Type CMOS
Distance sensor to bayonet:43,5 mm
Sensor dimension:22,3 x 14,9 mm
Resolution:5184 x 3456 pixels (18 megapixels)
Pixel Size:4.3μm x 4.3μm
Modification:DAW modification
ADC:14 bit per channel

© Coyright Rob Kantelberg
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