DIY telescope from MTO-500 lens and webcam

2013-06-10 06:05 | Categories: In English, Nuotraukos, Projektai, Užrašai, Video

I had an old Russian lens (MTO-500) laying around for a long time. Tried using it on DSLR, but because of lack of image quality I refused this idea. Today I mounted webcam on it. Because of smaller image sensor magnification is much larger in this conjunction.

Streaming live using Carambola2

Some frames mapped to wide angle photo

Shooting the Moon

There is nothing fancy with this setup. Couple of extension rings, adapters and webcam clamped to lens. Carambola2 is set to stream video using mjpg_streamer. (firmware is here)

To increase video quality I recommend tweaking webcam parameters (or adjust to your needs):

v4l2-ctl --set-ctrl brightness=10
v4l2-ctl --set-ctrl contrast=64
v4l2-ctl --set-ctrl gamma=75
v4l2-ctl --set-ctrl saturation=100
v4l2-ctl --set-ctrl sharpness=64

v4l2-ctl --set-ctrl focus_auto=0
v4l2-ctl --set-ctrl focus_absolute=0

To view all settings you can type this command:

v4l2-ctl --list-ctrls

You should see something like this:

root@OpenWrt:~# v4l2-ctl --list-ctrls
                     brightness (int)    : min=-64 max=64 step=1 default=23 value=10
                       contrast (int)    : min=0 max=64 step=1 default=35 value=64
                     saturation (int)    : min=0 max=128 step=1 default=66 value=100
                            hue (int)    : min=-40 max=40 step=1 default=0 value=0
 white_balance_temperature_auto (bool)   : default=1 value=1
                          gamma (int)    : min=72 max=500 step=1 default=106 value=75
                           gain (int)    : min=0 max=100 step=1 default=0 value=0
           power_line_frequency (menu)   : min=0 max=2 default=1 value=1
      white_balance_temperature (int)    : min=2800 max=6500 step=1 default=6500 value=6500 flags=inactive
                      sharpness (int)    : min=0 max=64 step=1 default=35 value=64
         backlight_compensation (int)    : min=0 max=2 step=1 default=0 value=0
                  exposure_auto (menu)   : min=0 max=3 default=3 value=3
              exposure_absolute (int)    : min=0 max=0 step=0 default=0 value=0 flags=inactive

mjpeg_streamer is set to start automatically on boot

/etc/init.d/mjpg-streamer enable

With settings:

root@OpenWrt:~# cat /etc/config/mjpg-streamer
config mjpg-streamer core
        option enabled          "1"
        option device           "/dev/video0"
        option resolution       "800x600"
        option fps              "30"
        option port             "8080"