Terrestrial photography with a telescope and DSLR

I setup my 8" Celstron Nexstar with f/6.3 focal reducer and Lumix GH1 to try out some "terrestrial" photography. I picked a public road in Redwood City, CA that has a good view and easy parking nearby. As far as I know this is a public sidewalk here.

Here is a shot with the GH1's stock lens at 14mm. The red squares indicate areas that I will image with the telescope.

Here's the stock lens zoomed all the way out to 140mm. This area is centered on the left red box in the first image.

This image was taken through the telescope and f/6.3 redcuer, so it is effectively 1260mm f/6.3.


This image was taken through the telescope at prime focus 2000mm f/10. Note that with the GH1 crop factor, the field of view here is comparable to 4000mm in standard 35mm SLR terms. Most of the blurriness is coming from air currents and haze. I will try again on a cool, overcast day, and I would expect better resolution. I am also eagerly awaiting my telescope remote-focus project to be completed. It's extremely difficult to achieve perfect focus while touching the telescope's focus knob, so it's possible this photo was taken slightly out of focus.



The distance is about 2.4 miles.



Here is a cluster of antenna across the Bay.

22 miles.

Here's another post of photos that I took many years ago with the same telescope and a Nikon 35mm film camera.
http://benkrasnow.blogspot.com/2009/09/telescope-magnification.html

I forgot that I even had an eyepiece projection adapter. I'll try it out next time, but I suspect the limiting factor will be air clarity not the telescope optics.

Increasing wireless video range with a DIY Yagi antenna

I recently bought a SecurityMan ClearCam so that I can see who is at my front door when I am out back in the shop. The advertised range was 330ft clear line-of-sight. In my installation, the camera will have to beam its signal through walls, and the the distance will be about 150ft, so I thought I would be fine. The reception turned out to be pretty bad, so I added an antenna that is more directional than the included quarter-wave piece-of-wire antenna that comes with the unit.

I built a 3-element Yagi antenna that was designed for 910 MHz, which is what the camera claims to use.


I built a corresponding antenna on the receiver. This arrangement provided a helpful improvement, but the reception at 150ft through some walls is still not %100. Frustratingly, the image appears perfect, then suddenly degrades and goes completely black, then returns to perfect again every 10 seconds or so. I have no idea why this would happen. The 910MHz band was specifically chosen to avoid interference with 2.4GHz devices such as WiFi. Oh well, it seems to work well enough for my application.