Ocal-EC Electronic Collimator User Manual
- June 9, 2024
- OCAL
Table of Contents
OCAL Electronic Collimator PRO
User’s Manual
Ocal-EC Electronic Collimator
The information contained in this document is property of Chaoxing Education Technology Co., Ltd. The information in this document is subject to change without notice. Please visit our our official website: http://www.ocalworld.com/en/ for latest version of program.
Version
| Date | Version | Content |
|---|---|---|
| 20-Jun-21 | 1 | First version |
Introduction
1.1 What is OCAL?
Thank you for purchasing and using OCAL electronic collimator. OCAL electronic
collimator is an ideal and superior tool for carring out precise collimation
of Newtonian reflector, Ritchey-Chrétien telescope and other reflecting
telescope.
Collimating your telescope by our OCAL is an easy and conformtable
excperience. By idea condition, it’s easy to archive minium 0.08mm primary
mirror axial errior.
OCAL PRO is upgraded version from OCAL. Not only change outter shape but also
more precisely calibrated of image sensor’s position. We include M42 to M48,
M42 to 1.25 inches adapters with OCAL PRO. By using OCAL Pro, you can easy to
operate it by mobile phone. It’s more convenient to collimate your telescope
without laptop or desktop PCs. Before using OCAL, we strongly suggest you read
this manual at first place. If you have any question about OCAL and
collimation of your telescope, please contact us via email :
huogo558@gmail.com or WeChat ID: 175768073. We
will reply you ASAP.
Product Description
2.1 Product Parameter
ocal side length is 51mm, height 32mm, weight 134 gram. connect PC by a USB
type A male / USB type A male cable,connect to mobile phone through OTG
adapter.support Android and Microsoft Windows 7 and above operating systems.
2.2 What’s in the Box
2.3 Software
Please download the OCAL operation program on the offical website. Both PC
Windows base and Android Tablet/mobile phone are supported.
2.4 Product Safety Issues
OCAL is certificated by U.S. FCC and EU CE to ensure property safety.
Prepare to Use OCAL
3.1 Install the Collimator
There is M42 x 0.75 female threads on OCAL after open the top cover. We
recommand the following methods to setup initial OCAL
3.1.1 If your focuser has M42 x 0.75 male threads, just screw up OCAL to the
thread on focuser directly.
3.1.2 If there is no threads at ending of focuser and it use compressing ring
or screw fixed brass ring. Please use some kind of extension adapter, such
like 2-inch to m42Screwing OCAL to the coupling threads of coma corrector
lens, and insert coma corrector lens into focuser directly. This method will
get more precise collimation.but this will cause the picture to be unclear,
please choose according to your own situation.
3.2 Connect to the computer
Just connect OCAL to the computer through the USB type A cable which attached
with OCAL product.
Plug and play on Windows operation system.
3.3 Precautions Before Use
3.3.1 Eye Point
We denfine the distrance from secordary mirror to OCAL as “Eye Point
Distance.” The OCAL view of A and B have little difference bewteen red and
greed circles.
The eye point of type A is shorter distance than type B. We will see large gap
between red and green circles, that means we are easy to distinglish red and
green circle. However, OCAL at type B eye point distance, we will get more
precise collimation result due to the its near real well focused posion. We
recommand you trying type B whlie carry out collimation in order to get best
result.
3.3.2 Attached a White Paper
Paste a suitable size of white paper behind the secondary mirror at side wall
of telescope tube. That makes the shape of secondary mirror is easier to
observe.
| Paste a white paper at tube | With white paper behind | Without a while paper |
|---|
3.3.3 Center calibration code
Each OCAL has it’s individual center cailbration code. At first, find printed
series number on your OCAL, look up SN and paste the data in that raw and
paste into focus.txt that in the same folder with OCAL program.
3.3.4 Operating OCAL program
Main screen
After execute OCAL.exe, then “Turn on Camera”.
Drag the corner of Camera window, to enlarge the display size.
Click “Camera Settings”. There are some video setting. Adjusting Brightness, Contract or other setting to a suitable value.
Click “Camera Control”. Try to adjust Focus and Exposure to suitable value.
3.3.5 Center offset function
Due to manufacturing and telescope adaptor tolerences, the OCAL program
reticule may not perfectly in geometric center, we use center offset function
to do slight adjustment.
The adjustment method is quite simple. Just find a circumference inside coma
corrector or focuser.
Then use it as reference to adjust the offset value.
Check Circle 1 on, it shows a “green” circle. Adjust it’s size to match the
inner circumference of coma corrector lens.
Here have gap. Adjust offset value to make green circle to fit the inner circumference of coma corrector lens.
In this example, green circle is perfect matched. And center offset value is
Vertical: 2; Horizontal: -3;
You may save these parameters by click “Save Config.”
3.3.6 PRO Version Interface Introduction
The interface of the PRO version and the computer version are different, but
the functions have been perfectly reproduced. The following picture is an
introduction to the interface of the PRO version.
1 Exit 2. Basic settings 3. Fine-tuning button 4. Select round button 5.
Length and thickness button 6.
Save config 7. Center offset function 8. Display working area
- Exit button, click to exit the software.
- The basic settings of the computer version, the brightness, contrast, focal length and exposure,parameters can be adjusted by pulling the adjustment lever.
- Adjust any adjustment lever in the software, which can be finely adjusted through the +button. the value of a single click increases or decreases by 1, and a long press can accelerate the speed by 10 times.
- Click on the optional red, green, blue circle and cross star.
- The length and thickness of the selected red, green, blue circle and cross star can be adjusted.
- Stand-alone saving config is to save the parameters. long press is to input the centering code. for the mobile version, the Center calibration code must be entered in X and Y axis separately. For example, the centering code is 0.01643.82.1432.28, the input value of X axis is 1643.82, Y axis the input value is 1432.28, after the input is completed, click Save to take effect.
- Centering offset function, the function is the same as the PC version.
- The software work area display interface.
Step by Step Collimation
4.1 Define Orientation
Before we start collimating the telescope, we define the orientation in order
to understand more clearly.
You may rotate OCAL some angle to make video display as above.
The most important collimation step of Newtonian telescope is secondary mirror
positioning. Once secondary mirror positioning is done, then you have done the
most difficult steps to carry out.
4.2.1 The first step position of secondary mirror
Figure 1
At begining, this is a no collimation example. Let’s go.
Figure 2
Slight loose the center screw of secondary mirror holder. Rotate the holder
and let the secondary mirror towarding to OCAL.
Figure 3
Check “Enable” to show circle 1 and 2. In the example, they are red and greed
circle. Then adjust the size of both circles to roughly equal secondary and
primary mirror.
Figure 4
Try to adjust A, B, C screws of secondary mirror holder. Let primary mirror to
roughly in the center of secondary mirror.
Figure 5
Rotate secondary mirror. To make sure the reflection of primary mirror in the
secondary mirror is concentric with “red circle”.
Figure 6
Now, we skip notice primary mirror. Adjust B and C screw of secondary mirror
holder to make the outter shape of secondary mirror fit to “green circle”.
Figure 7
Change the radius of green circle on main program, let the size of green
circle matching secondary mirror. Same as the adjustment of fingure 6, fine
tune secondary mirror holder screws.
4.2.2 The position of the secondary mirror and the primary mirror
Figure 8
After the adjustment at figure 7, position of secondary mirror is correct,
however the position of primary mirror become incorrect. All we need to do is
to repeat the adjustment from figure 2 to 5.
Figure 9
After few adjustments, secondary and primary mirrors are concentric.
In this example, there is some gap between bottom side of secondary mirror and
green circle. Try to adjust screw A to change the angle of secondary mirror.
Figure 10
Change the radius of red circle on main program, let the size of red circle
matching primary mirror.
4.2.3 The height of the secondary mirror
Figure 11
After all above adjustments. You may still find there is gap between green
circle and edge of secondary mirror. In this case, loosen 1/4 turn (or less)
of main screw of secondary mirror holder to downward it’s height. And repeat
the adjustment from figure 2 to 5 again. If the gap is at top side of
secondary mirror, all you have to do is tighten the main screw.
4.2.4 Adjustment of the primary mirror
In this step, we are going to deal with the three collimation screws of the
primary mirror support. Before this, we must loosen the three lock screws at
first. This step is a fairly easy compared to the secondary mirror adjustment
that we have just dealt with.
OCAL program have following assistant indicator to help you to carry out
primary mirror collimtion. That are crosshairs and small size blue circle. In
the next step, we will explain how to use this function to carry out primary
mirror collimation.
Figure 12
Check “Enable” to turn “blue circle” and “purple crosshair” on. Adjust to the
similar size of blue circle to OCAL. Then loosen the three lock screws of
primary mirror holder. Try to tighten one of collimation screw in order to
find out the direction of movement of OCAL and primary center mark which
reflected on secondary mirror.
Figure 13
Adjust 3 collimation screws to make blue circle fit OCAL outter shape and
center mark on primary mirror is also correct centering. In left result, your
telescope is perfect collimated. Every circles are concentric.
However in some cases, the center mark on the primary mirror is not able to
perfect centering. That becausee some telescope makers made flaw on paste
center mark. We will explain how to do in addendum.
4.2.5 Addendum
A perfect collimated Newtonian telescope by OCAL will find the following
features:
(a) Green circle and secondary mirror are concentric; red circle and primary
mirror are concentric.
(b) Crosshair and spider vanes are overlapped.
(c) Blue circle and OCAL are concentric.
(d) Center mark on primary mirror are overlapped to carema lens of OCAL.
In this example, features (a), (b) are true, but no matter how to adjust, (c)
and (d) are not able to archive. Then maybe the position of center mark of
primary mirror is not correct. Here is a example:
A Case of Actual Sharing
Version : 1.30
06/20/2021
References
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