Air turbulence is clearly visible on full moon video close to horizon

This is my first video from the second hand skywatcher maksutov 150/1800 telescope, which I bought. This OTA (Optical Tube Assembly) came with an old Celestron AS-GT (CG-5) mount. For the moon photo, I used a manual skywatcher EQ5 mount…

The moon was about 12 degrees above horizon, and with this maksutov and with a 2x teleconverter one can clearly see the air turbulence… The screen size of video below is 25% of the original to reduce the size of the file.

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DIY CCD camera to Finder scope adapter

I bought a second hand telescope which came with a CCD camera ASI120MC and I will try to use this camera for autoguiding by adapting it to an old finder scope .

I managed to get a 50/30mm rubber adapter from local hardware store, and tried if that fits. The picture below shows the 8×50 finder scope after unscrewing the 2 back pieces out from it. Under these 2 pieces one can see also the 50/30 rubber adapter.


Luckily this worked! The connection is very tight, and one have to be carefull when using the force.It is better to connect first the rubber adapter and then the CCD adapter, and CCD as the last one. The final focus adjustment can be done with the front (objective) lens, because there is a separate locking ring (left in the photo).


This setup should work with moderate focal lengths. I have telescopes with 500, 900, 1200 and with 1800mm focal lengths and I think this will work at least with the first 3 ones.

I have not use autoguiding before, so let’s see how this will turn out… (There are good software alternatives, eg. Open PHD guiding .)

Posted in Camera and telescope, DIY, For Fun or Interest, Gadgets, Hobbies and Other Interests, Tips, Tools | Comments Off on DIY CCD camera to Finder scope adapter

DIY eyepiece to EOS lens adapter

For some time I have been thinking if it is possible to re-use the camera lenses for something else, or with some other camera/detector. And I found some plastic adapters which one could print with 3D printer, eg. this.

As I happen to have an unused erecting eyepiece from telescope, and also other camera and telescope accessories, then I wanted to try if one could re-use the existing pieces. After some trial and error, the final adapter can be made from the following 2 pieces: telescope eyepiece 1.25″ to 2″-adapter on the left and 13mm extention ring on the right (for EF lenses).


In order to make this to work, the plastic 13mm extention will need to be permanently modified by removing the metal pins and by cutting the extra plastic out. The plastic was cut out on the bottom side in the picture above. This reduced the thickness of the 13mm adapter and gave better fit as the eyepiece adapter (50mm) fits over the plastic part of the extention ring, see picture below.


In the final setup, the end of the eyepiece comes very close (see photo below) and causing worries that what if the lens would come too close and get damaged. Depending on the setup, one could consider to use a teleconverter in between because it has no moving parts and would prevent any damage to the lens itself…


Why to use erecting eyepiece? For visual usage, when the erecting eyepiece is used with this adapter, then the picture is visible “as normal”. But if one is using typical telescope eyepiece, then the picture would be upside down. If one uses this with webcam or with CCD, then would not matter…


When this 10mm eyepiece is used with 50mm lens, it gives 5 times magnification. Since this 50mm camera lens (in pictures) has f1.4, then this might provide a lot of light at night sky…

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Discussion topic, short definition for security?

If you would need to explain security in an easy way, how would you define it? I came up with 2 definitions.

What is security?

  1. “Trying to influence people to take right decisions on complex things while using layman’s terms”
  2. “It is about getting ready for the bad things”

Any other ideas?

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DIY filter adapter for a camera lens without filter thread

Some camera lenses like Zenitar 16mm (F2.8) do not have a commonly used filter thread at the front of the lens. However, it is possible to make your own adapter. An easy non-destructive way is to used filter adapter rings and some tape. For landscape and sky photos this might be good enough solution.

In the pictures below: on left, the 58/62 ring rests on top of the lens frame. on right, the 58/62 ring is being placed inside the tube and next will be covered by the last 67/77 step-up ring.


In this DIY solution, an adapter ring 58/62mm is placed inside a tube made by 67/77 (step-up) & 77/67 (step-down) adapter rings. The 58/62 ring prevents the tube moving too close to the lens. Some tape around this 58/62 ring is needed. Also about 3 rounds of tape is needed around the lens frame to make the tube to fit tight to the lens. The focus ring is left free, as the adapter tube is short enough.


The final setup is shown below.


Posted in Audio and Video, DIY, For Fun or Interest, Gadgets, Hobbies and Other Interests, Tests, Tips, Tools | Comments Off on DIY filter adapter for a camera lens without filter thread

Touchscreen on Raspberry PI, to show key performance data

A tiny touchscreen on portable Raspberry PI (RPI) might be very helpfull for showing sensor values or key performance data like memory, CPU level or disk space left. My intention is to build a portable air quality monitoring tool based on RPI. This monitoring system will be able to show values of temperature, humidity and dust level.

This blog is about the first step, to use the screen for something simple, like showing key performance data. The figure below shows how the 3.2″screen looks like when attached on top of the RPI. I got my TFT Display 3.2 V2 on a good discount on a local computer store 🙂 …


Operating System

First I tried to get the screen working with the current raspbian OS. After some trial and error, I decided to try the manufacturer’s OS image. And as it was working right away, then I continued with that path. Remember to use “sudo raspi-config” command to configure your keyboard, localization, time etc.

One can clean up and remove the unnecessary packages, eg. wolfram-engine, libreoffice, sonic-pi and minecraft.

dpkg --get-selections > packages.txt
dpkg-query -Wf '${Installed-Size}\t${Package}\n' | sort -n > packages-space.txt
sudo apt-get purge wolfram-engine
sudo apt-get clean
sudo apt-get autoremove
sudo apt-get purge libreoffice*
sudo apt-get clean
sudo apt-get autoremove
sudo apt-get purge sonic-pi minecraft-pi
sudo apt-get clean
sudo apt-get autoremove
sudo apt-get purge scratch scratch2 squeak-vm squeak-plugins-scratch
sudo apt-get clean
sudo apt-get autoremove

Link: How To Free Up Some Space On Your Raspbian SD Card? Remove Wolfram & LibreOffice

Text mode in console

At first I tried to use the text mode in console, but this display (with 320×240 pixels) is still too small for anything more serious work. It is better to use the ssh (putty) over wifi to operate anything on command line. However, if you wish to use the text mode, then one can use “sudo raspi-config” to activate booting into text mode. And the font for the console can be set in console-setup file by adding 2 lines, see below (see link).

sudo vi /etc/default/console-setup

It is possible to utilize a virtual keyboard (eg. matchbox-keyboard) , and use the mouse for typing (see link). And/or one could simply activate a screensaver called termsaver, which has several utilities like matrix, clock and system monitor.

sudo apt-get install termsaver
termsaver matrix
termsaver clock
termsaver sysmon

Graphic mode in touchscreen

As the goal is to create a portable “low security” gadget for measuring the temperature, then one could easily activiate the windowing mode with automatic login (by using again the famous command “sudo raspi-config”). At reboot, the X-server environment is automatically started. In order to launch your custom script/tool, then one can follow the instructions here, and add the corresponding line in autostart file:

vi /etc/xdg/lxsession/LXDE-pi/autostart
@/usr/bin/python /home/pi/Display/

Custom start script in the touchscreen
pitkgui script in github was used as a base for the customized script, and it can be modified to provide different performance values to be monitored. The screenshot below shows the output of the customized script ( (The screenshot is taken with scrot command. One can install it with “sudo apt-get install scrot” command).

2018-05-07-001551 320x240 scrot

The custom1 and custom2 buttons are still unused, and will be used later for the humidity and dust level sensors. (The 3 hardware buttons outside of the screen could be used by another script…)

Posted in Anvanced Tools, DIY, For Fun or Interest, Gadgets, Hobbies and Other Interests, Innovation and new tech, Internet of Things and M2M, Raspberry Pi, Tests, Tips, Tools | Comments Off on Touchscreen on Raspberry PI, to show key performance data

Wireless router with 4G USB modem/dongle, by ROOTer

Previously I managed to get the OpenWRT working on a wireless router. As this router also has an USB port, I tried to get an USB 4G dongle working on it. After realizing that the solution is very much dependent on router itself and on the 4G dongle, and that I simply didn’t have all the details that was needed, then I gave up on that attempt.

And then I found that there is another effort/package called ROOTer, which is actually solving the very same problem for several routers and dongles. And that my specific HW was actually supported! After following their instructions, and installing their firmware, it worked “out of the box” (all actions from the GUI, without needing to do tweaks on the command line.) The only catch up to remember is that one need to configure the Modem data (eg. APN name, authentication etc), and when changing those parameters, they don’t become active until reboot is made.

My setup:

  • Wireless router TP-link TL-WR1043ND ver.2
  • 4G dongle ZTE MF831 (so called hostless USM modem, as these modems appear as an Ethernet device when plugged into the router)


In picture below, the model name and firmware are visible.


In next picture, it shows that the interface wan1 (4G dongle on USB) is up. It is possible to configure both the WAN (the physical cable) and 4G at the same time.


The zoning options are numerous. It is even possible to create quest wifi. In the picture below it shows the out of the box setup.


Other links:

WIKI – Smart ROOter OpenWRT routers using USB 3G & 4G modems

Posted in Anvanced Tools, Basic Tools, Cybersecurity, For Fun or Interest, Gadgets, Hobbies and Other Interests, Innovation and new tech, Internet of Things and M2M, Recommended Free Tools, Tests, Tips | Comments Off on Wireless router with 4G USB modem/dongle, by ROOTer