Northwest Astro

The blog has been down a bit the last few days. The shared server I use apparently came under election-week strain. Since it uses a single address for possibly dozens of sites, even one getting hammered can bring all the sites to a crawl.

I took advantage of this to do a couple small upgrades since some of the updates to the address servers were going to take up a full 24 hours anyways. You should notice that the URL is now www.nwastro.net, and you shouldn’t notice any more downtimes due to the shared address. Some further tweaks to the layout have been done, and I have a couple more minor changes that will probably show up down the road.

Things have been cloudy around here, lately, so not a whole lot of time under the stars these days.

I’ve bought my two new scopes, and very quickly learned that used gear is quite often the better deal. If I am looking for something specific, I’ll hit up the used market first before buying new. If I don’t need the part in the near future, I’ll wait until one shows up on the used market.

I see 3 major benefits:

1. Used gear holds its value longer.
   Astronomy gear is interesting in that it is actually a bit like a car. The moment you drive it off the lot, it loses at least 15-20% of its value. After that initial drop, the value doesn’t really change very much until that model is made obsolete. And for eyepieces, some designs don’t become obsolete for decades. Scope models remain relevant for up to a decade, and sometimes longer. While you aren’t going to be making money, buying used saves you that initial drop in value, and limits your losses if you do need to get out of the hobby. 
2. Used gear is (usually) field-proven.
   A brand new piece of equipment, especially a scope, has not been under the stars. The first thing you wind up having to do is check collimation and star test it to see if you can discover any optical imperfections. Scopes that pass these star tests with flying colors tend to demand higher pricing, especially if the seller can prove it. Dr Clay is known for his Supercharge service, and scopes that have gone through the service tend to demand more money. The flip side of this is that you know how it will perform. If the seller has no proof of the performance of the equipment, then it is no different than buying the same scope new. Buying a new scope is a bit like the lottery, because you might get a good specimen, and you might not. You won’t know until it lands.
3. Used gear can be inspected before the sale.
   While again, this doesn’t work if the seller is untrustworthy, this has been a huge benefit to me. You don’t have to buy used gear blind like you normally do with new gear. You can kick the tires to some extent, even if the seller is across the country. You can ask for pictures, inquire as to how it was treated and used. For scopes you can ask for images of defocused stars to do a ‘remote star test’ of a kind. You can get a feel for the true condition of the product before laying out the money for it. 

Now, this might not be all the benefits, and there is always the trust pit-fall when it comes to buying equipment from an individual rather than a reputable dealer. But, I have found that buying used results in a cheaper set of gear at pretty much the same level of quality. Sure, it might have a couple blemishes or wear, but it is only cosmetic, and you can target only the sellers that sell pristine gear if it does bother you. As the optics have to be in good shape to deliver the promised performance, an amateur astronomer will usually do their best to keep lenses and other sensitive parts in good shape.

Now, I have not had bad luck with new gear. The ETX I had was in top shape and offered excellent optics. The 10″ Meade I have now looks like it might be one of the better specimens of the entire LX200R/LX200-ACF line with no inherent optical problems. Some of my cheaper gear I’ve had worse luck on, such as a 90-degree mirror diagonal that actually messes up the alignment of the scope’s optics.

Overall, I’d still recommend buying used, especially in the current economic climate. Some people selling are doing so in order to weather the storm, and I’d rather have my money going there. In addition, it is where you will start seeing more and more deals until the economy stabilizes and more people can afford this hobby again.

There are problems when it comes to astronomy gear. You go to sell something, and you wind up getting something back in return. Your never quite sure why you do it, but you do. I recently sold my original scope, an ETX-125PE. I just didn’t have the room or the will to keep it, a 10″ Meade scope, and a smaller refractor to piggyback on top of the 10″ Meade. One too many scopes. So, I found a buyer, but instead of just offering full cash for the scope, this guy offers up some cash along with an Orion 80ED.

To make a long story short, I took the offer as it would piggyback nicely on the 10″ Meade, and actually fit the role of a decent ‘grab and go’ if I got a tripod for it. This means the AT66ED went up on the chopping block as well for resale. Glad I got that one used so it will resell better. I’ve got a few comments on the used market, and why it is an amateur’s friend, but that is better served in a different post.

Double Cluster Then

Double Cluster Now

So, the first clear night in awhile was on Tuesday, and I am itching to see what this Orion 80ED can do with a camera hanging off the end. As I wasn’t entirely happy with the way the Double Cluster shots came out earlier due to the violet stars, I figured it was a good place to start. Setup the scope in the cold, let it cool down a bit, and started taking images. Didn’t get around to playing with them until late Wednesday night after working late. Still not entirely happy with the result, but I rushed through stacking, and took all 60 exposures rather than just the ones that didn’t show streaking of stars. I still think there is a lot of good data here as long as I am more picky about the images added to the stack. I’ll probably revisit it in the future.

So, the thing is… if you do your observing at an apartment complex, expect people’s questions and interest. Up until now, it usually has just been those in the apartments next to mine showing interest as they came home or left. Two people have looked through the scope, just to find that when it is focused for my poor eyesight, they can’t see anything. Next time I have someone there looking through, I’ll have to make sure to use my glasses to focus for them.

Tuesday night though, that was something else. I got the scope setup, aligned, and aimed at the Double Cluster. I was only planning on taking images for about 40 minutes or so, doing a little bit of moon observing after that, and then head in. During that 40 minutes, I had 3 waves of people asking questions, interested in the pictures I was taking, and so on. A couple were interested in trying to look through, but since it was rather cold, I tried to ask politely to please not touch the scope as it was sensitive to that sort of thing while taking the pictures, and said if they saw me outside again, that I would be happy to let them see a few things then.

It got fairly quiet by the time I was done, and I took a couple shots of the Pleiades as a sort of experiment. I’ll definitely need more practice and a different approach before I can tackle that target. I just really got images of the Seven Sisters and absolutely no hint that there was a nebula here. Just hints that the dew had gotten to the lens on the Orion scope.

After that, the 10″ scope was pointed at the moon to see what I could see since it was still dew-free. I was greeted with some of the sharpest views I have gotten of the moon. Any night vision I had up to that point was completely shot, but the sheer level of detail I was able to get at high powers was amazing. It was possible to see fairly fine detail across the entire face, and make out craters I haven’t even seen before.

I might have to revisit the big moon photograph experiment during the next full moon, now that I know letting the scope cool down has an absolutely enormous effect on the detail you can capture.

Last night, the clouds broke and let me back under the stars in this light polluted suburb. I’ve been itching to use the small refractor on the Double Cluster for a couple weeks now, after I first attempted to get an image using the larger 10″ scope, and realized the two clusters together just don’t fit. Focal reducers help, but you are literally filling up the whole frame, which gives you no wiggle room when it comes to light falloff on the edge, or cropping away artifacts from stacking images together.

Draft

Processed

I managed to get roughly an hour worth of exposures with nearly perfect tracking, despite a rough alignment, and still tracking in Alt/Az. Unfortunately, I forgot to bring out the dew shield for the 10″, so after the images were taken, there wasn’t much hope for doing any visual observing with the big scope. I took my dark and bias exposures before heading in for the night.

This morning, I’ve been cobbling together the work from last night, running the data through pre-processing, and using the Drizzle stacking method for the first time in Nebulosity. I’d say the results turned out rather well after letting it grind on 85 images 12 Megapixels in size. With a DSLR, I find that you really don’t want to let Nebulosity scale your image up too much, as you already have an awful lot of pixels available.

I’ve posted two results. The first is my draft image of the Double Cluster, where most of the work after the stack was done by manually setting white balance and adjusting levels. The second is the more heavily processed version where I let Nebulosity try to filter out the skyglow for me before adjusting the levels, and I more aggressively cropped the clusters. You can more easily see fainter stars in the second, more processed image. Unlike most, I don’t like blowing out my stars to make the faint stars brighter and instead go for a more ‘faithful’ approach, and unfortunately that does have the effect of keeping the faint stars darker. Because the shot was taken at ISO 1600, it does still have a fair bit of grain in the image even after processing with a fairly sizable stack of darks. I am still learning a bit, and may revisit these particular images in the future when my post-processing skills get a bit better.

Anyone trying to visit the gallery in the last 24 hours might have had a few problems. The gallery layout and theme got a bit of an upgrade to better match the rest of the site. Some of the advanced bits got cut, like comments and image reflections. However, ratings are kept, and the layout should be cleaner and more consistent compared to before.

Astrophoto Gallery

For those who have started to accumulate bits of gear for long-exposure photography via a laptop, and are running out of ports, usually the first thing you consider as a fix is a hub. What if powering the hub over USB using the laptop isn’t enough? Then you are in trouble because you can’t just go out and buy the ‘car adapter’ for your USB hub. Doesn’t mean you can’t make one though.

In my case, I came into a Belkin USB 2.0 4-Port Hub on sale, and I liked the design that it had two USB ports on the side, and two on the top. It would help me later on if I decided to put the hub and a couple other USB devices into a single hobby box. Building a ‘hub’ which instead exposed 2 USB ports, a Serial port for scope control, and an autoguiding port for long-exposure adjustments could be an interesting side project down the road.

The problem is that this Hub will be expected to be used in the field, with all 4 ports in use. Total current would be very close if not a bit over the 500mA limit the laptop is allowed to provide. Also, this sort of drain would shorten the battery life of the laptop in a noticeable way. Instead, why not try to power it with 12V batteries and power tanks commonly being used by amateur astronomers to power their gear?

First, you need to track down a 12VDC car adapter at the right voltage and amperage rating for your purposes. For a USB hub, it is safer to get a high-amperage car adapter with a fuse, instead of trying to go for something more common but rated for lower current use. I found this High Power Car Charger for under 10$ and makes a good target for a quick DIY project. It is rated for up to 2A, and when it arrived, I found out that it also uses a 250V/1.5A fast-blow fuse in the plug. Perfect for my uses, and easy to modify because it already provides the right voltage to the output, it just needs the right plug.

To do the mod with this particular hub and charger (other hubs may be a bit different on the plug it accepts), you will need one more part from Radioshack: a size H DC plug. If you are attempting to power a different 5V hub, then you will probably want to get the outer diameter (OD) and inner diameter (ID) measurements from the manual, or take the AC adapter with you to a Radioshack to get the right part. Read on for the beginner’s Do-It-Yourself instructions.

Read the rest of this entry »

Duck in Pond

Another quickie post on the local wildlife.

Our apartment complex tends to attract ducks and migrating geese passing through. The complex is dotted with small man-made ponds which are hooked up to a drainage system in case of heavy rains. Outside of the drainage, they are left to develop naturally, and so it attracts the ducks as a source of food. While taking this photo along with a couple others that haven’t been posted yet, one of the ducks even tried to capture and eat a dragonfly.

AT66ED

LX200R

47 Megapixel

As a sort of ‘well, duh’ moment, I finally got the new scope collimated properly for the first time since I got it last night. The results were immediate and obvious. First thing I did after collimating was to point it at the moon that was just starting to wane as Jupiter had already sunk too low.

The resulting detail was pretty amazing. I went ahead and grabbed a shot from the AT66ED and the newly collimated LX200R to compare between the two. I also posted a full 47 Megapixel version of the LX200R image that lives outside the gallery for those curious about the full-resolution mosaic.

Tonight I was able to get out early enough to get a little visual observing in on Jupiter, but no chance to capture any video to see the difference it will make when trying to stack up an image. The views I got were rather impressive though. Jupiter’s bands were well defined, and I could make out the northern bands quite clearly. Also I caught a moon’s shadow on the face of Jupiter, clearly defined as a black spot, the first time I have been able to see that level of detail visually. Hopefully this will become a treat once I get the chance to point the scope at Jupiter for imaging purposes.

Ring Nebula

Took the scope out again last night, and decided to try imaging using my 0.5 reducer on M13 and M57. Unfortunately, I picked the wrong order, and so things were not as fruitful as I expected. I started on M57 before trying to image M13, and so M13 was entering the trees by the time I got to it. The end result is that I might as well have been imaging without the reducer at all. It was a total bust, and the colors were off, possibly from stray light off the treetops.

M57 turned out a bit better, but now I fully realize just how much light comes out of these nebula along the hydrogen emission lines. With the stock IR filter on the sensor, it blocked most of the red color, and no amount of post-processing could get it back.

This was also my first night seriously trying to use dark frames, and I think so far the dark frames have been doing what they need to do and reduce noise. Also, I realize this particular focal reducer is not what I want to be using. It exaggerates the curved field to the point where there is a very small area to image with. I should probably sell the 0.5 reducer and get a 0.63 reducer/corrector instead. Although I might keep the reducer for visual observing, as the extreme curvature isn’t as noticeable there, and the views are still rather impressive.

It seems like a rite of passage, as nearly everyone’s first deep sky image is of the Great Cluster in Hercules. It is bright, and you can take good images in under 30 seconds so you don’t need to put a wedge on your tripod to take the picture. At least as long as your stacking software can handle rotation + translation between images.

Half-Moon

Before we went out front to do any observing though, I managed to get a few shots in RAW of the half-moon. One of them turned out to be pretty good. 1/200 second exposure at ISO 100 with the focal reducer. Having a hard time getting focus and I am starting to suspect the focal reducer might be involved.

So after we got the scope set up out front, I showed him a few objects, like Jupiter, M13, M57, the usual starters in the summer sky. Unfortunately the level of light pollution makes visual observing of galaxies fairly difficult. Later on we were looking at the Double Cluster in the f/5 focal reducer and noticing how one cluster looks pretty average, while the other has 3 bright red stars in it. He commented “You should photograph this.”

Draft

Processed

So, I hooked up the DSLR to the scope for deep sky for the first time and tried taking shots of the Double Cluster with the focal reducer in place. Everything seemed curved and stars ‘blown out’ (loops of unfocused light flaring out from the star). Removing the focal reducer, I pointed it at M13 instead and took 50 exposures over about 30-40 minutes. The best 13 frames make the two images you see below.

The one on the left is a little unprocessed, and you can easily make out the skyglow from the moon and light pollution. The one on the right has been processed to try to darken the background as best as possible without using a mask, as well as try to bring out some of the color differences in the stars. M13 is a mix of yellow and blue stars, and I wanted to make that obvious to someone looking at the image.