Hooked! Must. Upgrade. Now.

Every hobby has changing interest, intensity and expectation levels. Different levels of astrophotography have a ceiling, and those ceilings are usually created by equipment. While I thought I had a ways to go until reaching my ceiling, I saw some areas where I needed to poke through to move toward my specific goals. I’m admitting to the obvious fact that I will be hooked on this hobby for the foreseeable future, and should probably get a little more serious about it to start bypassing frustrations that are within my control. This, of course, means spending money. But I’m not spending money like you’d think. As I’ve probably said a hundred times, I’m married, three kids, two dogs, a mortgage, blah, blah…. Disposable income is a fairy tale in my house. So when I say I’m going to spend money, I mean a couple hundred dollars, not a couple thousand.

I debated with myself on what to upgrade. What would be most effective for me right now for the least amount of money? The lessons of last Fall and Winter have taught me that I need to make the most of my time outside. While I was outside quite a few nights, I was probably outside a lot when I had no business imaging, I would say from mid-November through February we had 4 or 5 nights that gave me good data. Each of those five nights were all shortened in one way or another. Either I was fighting with my gear, Microsoft updates “broke” my gear, and/or the lack of ability in my camera’s data acquisition meant more time with fewer results

I would love to go out and buy a Celestron CGX or iOption CEM60 mount, but $2200 isn’t in the cards right now. I toyed with trying to find a used CEM25 because my imaging gear is only about 16lbs, but even $700-800 is well out of the budget right now. I was also able to sort out some declination guiding issues, allowing me to keep the guiding RMS right around one arc-second when I’m very well aligned. I still think that’s pretty crazy for a 14 year old LXD75 mount. With my current camera and field of view, an RMS of even a bit over one works just fine.  So, how do I make my images better? I picked three quick  and relatively inexpensive things plus a trip to the hardware store and several hours on the mount to get things rolling.

I’ve had a whole 3 hours of testing with these “upgrades”, but all went very well as explained below.

A Modded Camera:

  • I do still want to use my camera for daytime shooting, but I can deal with a custom white balance. To assist in continuing dual-use, I ordered the Baader BCF-1 filter (IR cut) replacement filter for the internal filter. I replaced the filter in just about an hour, but I’m very used to disassembling and reassembling electronics. If you’re skittish about taking apart electronics or losing little tiny screws, you might want to look into services that will do this for you. They aren’t cheap, but you know you’re camera will work when you get it back. Oddly enough, I’m doing this just in time for Galaxy season… when it matters much less. I’ll be waiting for the Eagle and Lagoon to get up in the sky for a real H-alpha+RGB test, but might do some playing with the Wizard as it ducks between trees in my back yard.

New Guide Scope:

  • I’ve been using a modified Meade 8×50 finder to be used as a guide scope. While not a huge upgrade, the ZWO 60mm helps me out quite a bit. I never got that 50mm finder setup quite right, and it was a front/side mount near the focuser of the OTA, creating balance issues. The new guide scope and camera are mounted piggyback, which allows me to more accurately balance the whole rig while also turning the focuser and imaging camera inward. Turning the camera inward makes the balance points more compact and forgiving. With the help of an actual focuser on the guide scope, my bright guide stars are now round, which leads to more accurate guiding and eliminates false adjustments due to equipment suckiness.

New Guide Camera:

  • This is the part I didn’t really “need”. the ASI034 was doing the job it needs to with the exception of rather bright stars not holding a perfectly round shape. Part of that also had to do with the homemade guide scope. Having a frustrating Winter, and knowing Juptier and Saturn will be on their way back at a decent hour made me bump up to the ASI120MC. Planetary work is quick in comparison to DSO work, and rewarding. This doesn’t mean that planetary imagers are producing anything less than deep sky imagers, or that they have it easy. To get to the next level of planetary imaging takes very specific equipment and precision. The ASI120MC is at the entry level for planetary imaging, and that’s where I’m at.
  • It looks like ZWO have finally stopped making ASI034, and most dealers have sold what had already been produced. The ASI120MC has also dropped $50 in price over the last six months, which really removes the need for a $99US 0.34 megapixel camera.

H-Alpha Filter

  • Even with the modded camera, I know I’ll need some more punch to my images. I’ve only been testing with this filter for a couple nights, so I can’t say a whole lot about it yet. I did go with a 12nm vs. a 6nm, pretty much solely because of the cost difference.

About $2.50 at the hardware store:

  • …and a couple hours of adjusting and testing. About 10 years ago I had sheered of about half of the RA worm gear retainer collet. I jammed it back in there since I didn’t have a machine shop to reproduce the part. I never had much issue, but the RA was never as good as I thought it could be since I didn’t have anything clamping down that gear. So, a 25 cent nylon spacer brought the threads out enough that a $1.25 nut could grab on to the collet and solidify things.

Encoders:

  • One other thing I did a couple weeks back that resolved a big GoTo issue… The ancient LXD75 uses servo motors with insanely fragile encoder wheels. Apparently the declination encoder wheel was pretty messed up and a coat of chalkboard paint that I already had got me slewing and guiding right.

RA/Dec Percentages:

  • Finally, after reassembly and a motor calibration, I messed with the RA and Dec percentages to actually decompensate for backlash. It was a bit of a guessing game that I wasn’t able to complete until I was under the stars. I started high and went down to 2% on the Dec and 4% on RA. This change was probably the biggest differentiator in eliminating the declination flyaways that were ruining my exposures.

So that’s it. Some testing in poor conditions (enlarged single exposure example below) using 180 second exposures at ISO 800 gave me some of the smallest and roundest stars I’ve been able to accomplish to date. Not bad for a piece of crap that people insist can’t do the job! Though the want for that CEM60 has not diminished!

star crop

Not a bad graph for a mount way older than all of my kids. It was worth all the work.

guide graph2

Time will tell, but in testing it looks like these relatively inexpensive upgrades will pull my images up another level. Give them a look if you’re in the same situation.

Clear Skies – KA

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s