The dirt/sand surfaces found in many remote locations can make leveling an impossible task, or worse yet could cause your rig to slowly settle as you’re imaging regardless of if you walk close by or not.  To prevent such a thing from happening, you’re going to have to set your tripod legs on some sort of load spreading accessory.  Many companies make anti-vibration pads that would do the job but they can cost upwards of $100.  If you don’t want to spend money buying pre-made pads, your choices are to either deal with the sand, make your own pads or find some sort of suitable alternative.

This author decided that the easiest thing to do was to find some sort of suitable alternative.  A quick field trip to the local home improvement store proved to be the right choice.  It only took walking up and down a couple of aisles to find the perfect solution, banister rail caps.  They were the right size, light weight and the right price, $2.99 a piece x 3.

They came in handy during the last MBS astro trip out to Joshua Tree where it was sandy.  The tripod stayed in place without any slippage or sinkage and resulted in two successful nights of imaging.  Setting up was a lot easier this time around than the last trip to this same site.  This hobby, like many others tends to get quite expensive so any opportunity to save money is beneficial.  Sometimes it just requires a little bit of creativity!

Each subsequent frame started to slowly degrade from the edges in.  Nebulosity started showing where it shouldn’t be and stars were starting to diffract every which way just like the unprocessed shot to the left.

Since this was something I had never seen before, I kept taking a couple more shots until the last shot clearly showed the culprit…FROST!  It was like looking through a window in the dead of winter with the center of the frame still fairly clear but with crystal like spider veins on the edge of the frame.

M42 Frost, -5C

Well, for frost to form, two things need to be present.  A surface at or below freezing, and moisture.  Now, what could I do about the moisture?  Nothing at all.  I could do something with the temperature level of the CCD Chips though.  I was running at -5 degrees Celsius, so I decided to raise it to 0 degrees Celsius.  I know what you’re gonna ask, 0 degrees is still freezing so why not go to 5 degrees?  Well, the chip itself is at 0 degrees at the back surface but the front surface is just slightly warmer due to it being exposed to the air inside the camera body.

After letting it warm up for about 30 minutes, I started taking shots again and could clearly see a difference.  Most of the frost had melted and is evident in the stars at the left, bottom and right edges.  M42 itself is a bit sharper and the nebulosity isn’t artificially enhanced.  What is also evident is the amount of noise from the increase in temperature.  Eventually all of the frost disappeared and the rest of the shots I got that night were usable.

M42 Less Frost, 0C

After I got home, I immediately read over the manual and followed the direction on how to recharge the built in desiccant.  Fortunately SBIG’s design of the ST2000-XCM desiccant plug is very simple.  It simply screws out of the body, replace it with a dummy plug to prevent anything from getting in the camera and recharge it following the recommended procedure.

This happened almost after a year of use and in the fall, right after our monsoon season which makes sense since it was so humid.  So here are a few tips to follow to minimize the chance of your CCD Chip frosting over.

1. Store your camera in a cool, dry place
2. Throw a pack of silica gel or other type of desiccant inside your camera case when not in use
3. Recharge your desiccant plug (if applicable) on recommended intervals or before big imaging trips
4. If frost forms during an imaging session, set the temperature regulation to 0 degrees C or above

SBIG Desiccant Plug

Dummy Plug

I used a super long 60mm Tasco with a webcam mounted to it. It worked okay, but it wasn’t working so great with the clouds, and it did not help that I was imaging near the zenith. That meant that the webcam was near the ground. I spent so much time laying in the dirt that night that I had to come up better solution.

With a little online research on forums (www.cloudynights.com) I started reading about people using their finderscope as a guidescope with good results. This appealed to me because of its small size, wider field, and its easy mounting. Since I had all the necessary parts already, I decided to give it a try.

I had an 8X50 right angle Zhummel finderscope so I decided to give it a try. I was able to unscrew the mirror portion off of the finder, and also the piece that attaches that to the tube.

I had to figure out how to mount the webcam to the finderscope. I attached a .965 eyepiece barrell onto the webcam (from a Tasco-originally to use in a Tasco 60mm). It simply screwed on the existing webcam lens assembly. I added some epoxy to hold things down nice and tight.

I was able to unscrew the right angle mirror and viewfinder. Luckily the crosshairs are attached to this part.

I was trying to go as low budget as possible so I went to Home Depot and picked up two PVC parts. One piece fits snug inside the finderscope tube. The other piece fits snug inside of that and has an opening that a .965 eyepiece barrel fits into perfectly. I first did dry runs of everything.

Camera to adapter

Camera and adapter to sleeve

Now that I knew how I was going to mount everything I now could figure out where the webcam focused and position the webcam accordingly. Since I am able to adjust the objective lens by screwing it in and out, I will have some working room for focus. I wanted to position the webcam in the middle of where the objective lens would focus.

I had to sand down some edges to get the parts to fit perfectly. I like to take off as little material as possible. You can’t add material once you’ve gone too far. I sanded and tested, sanded and tested. It did not take too long since PVC sands easily.

Before I glued everything, I made sure I was able to focus. I also took a took a few shoots with the webcam to make sure the focus was right on.

After the glue dried I painted everything flat black with spray paint.

I took the oportunity here to make sure everything was clean before I did an instal. And since my tolarances were so tight, I had to do a little sanding after the paint dried. I was able to press fit the PVC adapter into the finderscope tube without having to add screws to hold it into place. No slop here!

Here’s the unit all together. A 1.25″ eyepiece cap fit the finderscope adapter perfectly.

Here is the completed product. I threaded three screws to really hold down the webcam. I also removed the plastic screws in the finder mount and changed them with metal ones. I also added a third screw next to the spring push to tighten everything down once a guide star is found.

Remember to get everything nice and tight, you want to rule out any slop (flexure) that can a ruin your guide setup.

On my first attempt a couple of weeks ago, I could not get it working. The calibration failed. I later realized that the telecope would have to move more when guiding because of the short focal ratio of the guidescope. A simple tweek in PHD from 750 to 1000 for the calibration step size was all that was needed to get this working.

Now I have a small light weight easy to setup guidescope! And it all fits in my Fat Max toolbox. No more laying on the ground trying to get a guide star.

This weekend I tested it again and I was always able to find a guidestar within the adjustments of the finder.

M44 Behive Cluster. 10 minute guided shot with a 8X40 finderscope and webcam.

Nikon D40

The answer is yes. You can take exposures much longer than 30 sec. but you have to do it manually. Set your Nikon DSLR (D40, D50, D60, D70, D80, D90) to manual (M) or shutter priority (S) and move your shutter speed to bulb. Now manually hold the shutter open for as long as you desire. You might find the use of a stop watch or timer helpful.

Hold the shutter open for 60 sec.,  for example, and release. The trouble with this is that you actually touching the camera will likely create enough shake to blur your image. So there are remote and hands free options available.

Nikon DSLR cameras that use an InfraRed trigger sensor can all use the Nikon ML-L3 Wireless Remote Control. This is a small remote control with one button. You press the button as if you were pressing the shutter release on your camera with the big difference of not actually touching the camera. This will eliminate your physical contact with the camera and any shake and blur caused by your touch.

The big challenge here is that you’re still holding the shutter open manually. In order to automate this process and set more accurate exposure times beyond 30 sec., you need to use a computer and some software to control your camera. Nikon offers Camera Control Pro, which allows you to control all of your camera’s settings from your computer.

For Astronomy.

There are also astronomy tools available for astro-photographers that will allow you to program and script shutter times longer than 30 sec., for less money.

Stark Labs writes software called DSLR Shutter, that will allow you to control shutter times past 30 sec., and repeat multiple exposures. DSLR Shutter is available for Free download from their site (however they’re always accepting donations.) DSLR Shutter will control the shutter only, allowing you to set multiple exposures of any time.
http://www.stark-labs.com/DSLR_Shutter.html

DSLR Shutter works great using an InfraRed USB Shutter Control unit. Shoestring Astronomy makes an IR remote that will connect to the USB port on your computer. The software works with the USB unit to trigger your camera’s shutter without having to touch the camera.

Shoestring Astronomy USB Shutter Control Adapter (DSUSB-IR1)

There are also IR cable solutions available from another manufacturer, Happ Griffin Astrocable and you can find them online at
http://www.hapg.org/astrocables.htm

When you combine the Shoestring Astronomy USB Shutter Control Adapter with the Stark-Labs DSLR Shutter software – you can shoot multiple exposures of any length – fully automated, without touching your camera and blurring images.

Another word of advice.

As you continue to take longer exposures you’ll notice your camera battery won’t perform as well as you’d hope. The longer exposures means longer recording times and more drain on your battery. You should always carry multiple, fully charged batteries or consider an AC adapter for your camera. Depending on which Nikon DLSR you use, you’ll most likely need a Nikon EH-5A AC Adapter. D40 and D40X users will need a second AC adapter part, Nikon EP-5 Power Supply Connector (see the links on this page). Once you have an AC adapter, your shutter times can extend beyond your expectations, allowing you full exposure freedom over time and space.

I use these tools for taking astronomy pictures – so please feel free to ask questions.

I show how to setup, balance and collimate this scope using a Baader Laser Collimator.