Piggy-backyard

To get me back in the swing of DIY enhancements and pictures, I came up with some goals besides “get a better camera.”  Better tracking, manual guiding, and use of filters seemed good goals.   Guiding a filtered piggyback camera appeared a good way to start.

Here’s the set up on the deck, with the 50mm f/1.4 on a small ball head piggybacked to the scope.  Lots of wires, including camera timer, paddle for dec/RA +/- guiding, heater, 12v supply, and focuser (not really needed for piggyback).  I need to add a heater to the camera too, I guess.

You can see the new bar on the bottom for counter-balance weights.  I looked to buy a dovetail system for this, but decided to make one out of a shelf bracket, sliding nut, and bolt with washers.  It didn’t take long and actually works pretty good.  Some of my tracking error in previous shots was likely due to lack of balance.

For the filters I had some 1.25 eyepiece filters from my dad (Hα, Hß, Oiii/UHC), but nothing I could mount on a camera lens.  Clip-in filters for a Canon camera body or lens are available, but pricey.  A little research and some measurements led me to the idea of making my own clip-in filters from the 1.25’s that dad had sent.  Unmounted, they are around an inch in diameter.

With a compass cutter and some foam left over from a dew shield, I started experimenting with making donuts to fit the filters on the inside and enough outside diameter to squeeze into the 42mm gap that crop sensor Canons have behind the lens.  The compass-knife I bought made quick work of this and I’m glad I didn’t have to cut a traced circle with an exacta knife.  It’s important to buy at least one new tool for a new project.

Here is the end result.  Pictures of actual nebulae will follow in my next post!

 

 

 

Camera Apart (late 2013, early 2014)

As I’ve mentioned from time to time, my Canon 1000d is modded in order capture more red light.  In September 2013 I first disassembled it to remove filter LPF2, which has a transmission curve like the graph the right, cutting transmission of reds and IR:

This went well (i.e. the camera booted and took pictures when I was done).  I left LPF1 in place, as is typical.  But I didn’t replace LPF2 with anything.  Typically one replaces LPF2 with a filter that cuts UV and IR beyond the H-α wavelength.  I think the idea is that you need to transmit H-α but _still_ aggressively cut IR otherwise your images can capture unfocused IR that has been refracted into the visible spectrum.  So anyway, my stars looked bloated and I wondered if it was this effect.  So I got an Astrodon filter from Hap Griffin that has a curve (black line) that looks like this:

6 months after I took the camera apart to remove LPF2, I replaced it with one of these AD40Ds.  Here is the scene of the crime:

 

 

 

I just came across these pictures today and realized I never went into the story in detail, so now you have it!  Did it improve my images?  I think it did, though I wish I had done some before and afters. Looking at my images from that time, maybe I’ll try to recreate the California Nebula image to see if it’s much different.  Drive correction is next on my list to try to get the stars smaller.

My thanks to Gary Honis and his fabulous resources for these DIY DSLR mods.

Lagoon Nebula

This year’s camping trip to Medicine Lake was planned to coincide with the new moon.  Unfortunately it ended up coinciding with a rash of wildfires around the state.  I was able to get this image of the Lagoon Nebula early on in the trip before the smoke got really bad.

6 Stacked 30s Exposures Canon 1000d modified/C8

International Space Station

I had big plans last night to drive down the coast and try to get a picture of the ISS transit of the moon during the eclipse.   I was packed and ready with scope, camera, and SW radio for a time signal.  Unfortunately the coast was shrouded in fog and high clouds, and after consulting GOES-West and some web cams, I decided not to risk the drive down PCH to get to the centerline.  My research did get me intrigued about the idea of capturing an ISS lunar or solar transit, though, and introduced me to a great website for this and other events.

Tuned as I was to what the ISS was up to, I noticed it would be nicely visible from our house yesterday evening.  I took this picture almost as an afterthought, so I didn’t set up the shot very well.  The green blotch reflection of the full moon, below the bright ISS dot, is a good lesson in the flare potential of wide open fast lenses.  Or that you need to take the UV filter off for such shots.

50mm f1.4 1/80 Sec ISO 3200

New Lens

Since I’ve been shooting a bit of camera piggyback on the scope, I’ve decided to take lenses a little more seriously.  All of my previous lens pictures have been using the 18-55 or 55-200mm Canon EF zoom lenses.  Not particularly fast, and with a lot of lens elements.  I just got my first fast lens in the mail, a second-hand Canon EF 50mm f/1.4.   Anxious to test it quickly, I took it out on the deck tonight and shot toward Vega.  This is a handheld shot of Lyra and vicinity, Canon T3 50mm f/1.4, 1/40th sec ISO 6400.  No post processing, just the jpg from the camera. (click it to show the full size)

With my eyes I couldn’t see much more than the summer triangle, (though not dark adapted).   So I’m pretty happy with the lens.

Medicine Lake #2

Next one from the Medicine Lake camping trip, also within Cygnus (because that’s where the trees were not).  The Veil Nebula.  Same exposure info as the previous post.

 

Images from Medicine Lake

We planned this year’s camping trip to Medicine Lake to correspond with the new moon. Here is the first of four objects I shot.  This is the North American Nebula at f/5.6 200mm 9minutes (18 exposures of 30sec each).  Piggy back.

 

Using my Work Skills for Play

The problem with the new latitude digital setting circle is that it’s in decimal degrees rather than degrees/minutes/seconds.  I made a table of bright stars with the converted formats, and started thinking about sketching in constellation diagrams.

Orion using stars from the HYG database

Then it occurred to me that since I have the knowledge and software to make maps of the earth, maybe I could make a star chart.  It’s been fun to try my hand at uranography.  There are a number of star databases out there, and it’s not hard to convert RA and Dec into longitude and latitude and plot and project them with GIS software.

These maps are quick and dirty, but I have some ideas about how I’d like the perfect star chart to look and the data I’d like it to contain.  (Hint: Like any good GIS analyst, I hate Degree/Minutes/Seconds).

I did take the time to vary the size of the stars by magnitude and the color of them by the color index.  Here are all of the stars from the HYG 2.0 database brighter than 7th magnitude in a sinusoidal sphere projection.  How many do you recognize?

Stars brighter than Mag. 7 (HYG 2.0)

 

There’s a Moon over Grizzly Peak Tonight…

Moon over Grizzly Peak

3/17/2014 21:08 2032mm f10 1/320s  ISO 1600

The last full moon of winter.  Picture taken from Albany Hill as the moon rose over Grizzly Peak in Berkeley.  The Grizzly Peak Electronics Site, a tower used by KPFA and others, is in the foreground (a little less than four miles away).

I got both lucky and unlucky with this one.  I’ve taken full moon rising pictures from the deck off-and-on for years now, but never through the scope.  I’d always wanted one with Grizzly Peak in the foreground, but I didn’t even know the antenna tower was there!  I had no idea this moon was rising over Grizzly peak until just before it rose but I had the scope ready.  I’d focused on house lights in the hills, and meant to focus on the moon once she appeared.  After some test shots before moonrise, I settled in.

And of course, technical failure as soon as Luna showed herself.  I thought the battery had died.  I lost a bunch of seconds until I realized it wasn’t the battery, and yanked out the remote shutter release, figuring I’d sent it into program mode.  All my pics then had to be finger presses on the camera, so I jacked up the ISO for faster shutter speeds.  Never had a chance to make sure I had a crisp focus.  Good enough, though.

3/17/2014 21:08 2032mm f10 1/125s ISO 800

 

Telescope Modified: Focus Remote

Focusing has always frustrated me, especially now that I’m taking a lot of pictures.  Humans are not well designed to focus small telescopes with their fingers.  Turn the focus knob, and the image bounces around.  Wait for it to settle down, and turn it again…

So I built a motorized focuser, based largely on Brian Sumpter’s design.  It works great.  I bought the servo, switch, and rheostat, but scrounged around for the rest of the parts (iPod case, erector set pulleys, etc.).  The breakthrough for me was using a grommet (I had a box of assorted grommets from Harbor Freight) to fit in the drilled out pulley center-hole and over the .5″ focus spindle.  I was also happy to figure out a way to attach the servo mounting rail to the scope without tapping any new holes.