Posts Tagged ‘Telescope’

The Caldron and the Laser

11 July 2018

Over the past few weeks, I’ve finally managed to explore a new part of Southwest Idaho and attempt some astrophotography.

I came across mention of the southernmost part of the Snake River and how it was also a mere 40 feet across at that point. Even the name, Caldron Linn, aroused my curiosity. I had to go looking and find where it was and why the name.

A bit of research finally pinpointed where it was on the map: close enough for a day trip. I hit up a friend to see if he wanted to check it out with me and when he found out where it was, he recommended a burger joint in Twin Falls for lunch: the Buffalo Cafe.

Caldron Linn has an interesting history. Linn is an old Scottish word for waterfall. So, essentially the name means Caldron Waterfall. It’s actually a series of waterfalls, three at this time of the year. The best time to go see it appears to be the March-May time frame rather than our late June outing.

Image of Caldron Linn showing the three main falls at the time we were there. For some sense of scale, the bottom falls is 20 to 30 feet.

From the historical roadside sign south of the falls:

In 1811 the Hunt party likened the terrific torrent of the Snake to a boiling caldron, adding the old Scottish word “Linn,” meaning a waterfall. They had lost a man and a canoe in a roaring chute upstream. Finding worse water ahead they abandoned river travel. Next year, another explorer said of Caldron Linn, “Its terrific appearance beggars all description.”

Even with the water low as it was when we visited, it’s still an impressive sight. I could spend all day there just enjoying the place and taking pictures. I definitely intend to return and spend the night. Aside from the wonderful day pictures possible, if I have done my homework properly, the Milky Way rises right up from the waterfalls, or pretty dang close.

Identifying the direction and location of a possible astrophotograph using the Android app Dioptra.

There is no approach to Caldron Linn from the south side, it’s all private land. To get to the falls, you must make the approach from the north. There’s a dirt road that includes a couple of switchbacks as you drop down into the canyon. I would not take a regular car there. Really, I recommend a pickup or SUV with decent clearance instead. Or bikes or quads, of course. Just use common sense!!

Pano of the Caldron Linn area from up on the rim of the canyon. There’s another switchback just left of where this was taken, right where you drop off the rim and start the road down to the caldron.

Now for the laser part….

When I do my astrophotography, one of the difficulties is knowing exactly where my camera is aimed against the black sky and how much of that area is actually going to be covered in the image.

Before I explain my simple technique, let me give you a few, very stern warnings.

First, lasers are dangerous. There’s no question about that. Pointing them into someone’s face risks blinding them or at the very least burning out a section of their sight. Never point a laser device at anyone’s face.

Second, it’s not only dangerous, it’s also illegal to point them at any airplanes. ALWAYS, always scan the sky to make sure there are no flashing, blinking lights moving across your view or near it. If there are, wait until they are gone. If they keep coming and going, just don’t use the laser…better safe than sorry!

Third, do NOT shine your laser through the camera from either end. You risk damaging the optics or the sensor.

The laser pointer is also wonderful for pointing out exactly where in the sky things are. For example, you can point your finger at Cassiopeia and say, “It’s that W on it’s side right there” but with so many stars, which ones make up the W you are referring to? With the laser you can point exactly to each star and draw from star to star, showing them exactly the W you are talking about. Or point out which “star” is Jupiter.

That said, I use my laser pointer to let me see where my camera is generally aimed and then exactly what part of the sky the image will cover. It’s also faster than making an exposure then adjusting the camera until you have what you want.

This is the laser pointer I use. It’s a brilliant green beam from hitting the dust in the air. Red might be better for preserving your night vision, but I’ve not noticed any issues using this green one.

Here’s how I do it:

  1. Eyeball aim the camera in the general direction of my subject by visually aligning the camera lens with the center of the area I want to cover.

  2. Put the laser pointer on the top of the lens and see if it points where I want it to. Adjust as necessary.

  3. While looking through the viewfinder and holding the laser pointer beside the camera, move the laser beam until you see it in the viewfinder.

  4. Move the laser pointer until it points, one at a time, to the four corners of the viewfinder. Hold the laser steady and take a quick look over the camera to see what part of the sky as a whole the beam points to.

  5. Adjust camera as required until the laser pointer, as seen at the viewfinder corners (repeating steps 3 & 4), covers the desired area of the sky.

NOTE, in no instance in the steps above do I point the laser pointer through the camera viewfinder. I hold it beside the camera, point it at my target, and check to see it in the viewfinder.

Steps 3, 4 and 5 actually involve repeatedly looking both through the viewfinder and over the camera at the sky so that I get an accurate idea of what part of the sky is framed in the viewfinder based on where the laser pointer beam is. That lets me know if the composition is what I want.

This is what my laser beam looks like when seen through the viewfinder. Since this was a long exposure (20 seconds), the beam in the image is fatter and dimmer from not being held steady. Visually, it’s actually a pencil thin bright green line out to whatever you’re pointing at.

Check out the above photo of the laser beam as seen when viewed through the viewfinder and you’ll get the idea. Notice how it goes off the image left? That’s because I am using the laser pointer in my left hand near the top left of the camera.

With the same caveats, this process also works well for aiming your telescope at something in the night sky. It’s especially useful if you’re talking with someone else and one of you is trying to tell or show the other where the object of interest is. With the laser pointer, they can point right at it and held on top of your telescope tube, you can quickly point the telescope to the right spot.

That’s it for this posting.


It’s been a while

22 October 2014

It has been quite a while since my last blog post. There’s been a lot going on in my life and at work so that I’ve not felt any desire to write at all. Now that things are starting to settle down and sort out, I think I owe my few readers an update, if only to let them know I’m not dead and will be posting in the future. The updates in this post will cover Astrophotography, General Photography, and Amateur Radio.



Well…as with writing, I haven’t been doing much of this since Wickahoney. It sucks, too, because the weather has been great for it. It hasn’t been a total loss, though.

I did crawl out of my warm bed to see the Blood Moon of the wee hours of 8 October 2014. I actually went outside in the driveway and watched it for a while before it dawned on me to grab my camera. So, I quickly went back in, grabbed the camera, and got back out. I don’t know what I was thinking, but I started taking pictures handheld. Trying to keep the ISO down in order to eliminate as much noise as possible, I was obviously shooting hand-held exposures that weren’t going to come out nice and sharp. Eventually I actually realized that and started bracing against the porch. That kept slipping, definitely operator error, so I moved to the car. The angle of the windshield was perfect but I was still getting blurry images due to the speed at which the moon moves. As I started dialing in for that by increasing the ISO and getting better and better pictures…my battery went to bed. By that time, the moon was emerging from totality so I just stayed up and watched the show a while longer then headed back in to bed.

Lessons learned: Get the friggin’ tripod, it’s only 30 seconds into the house and back out. Wake up more and think things through. Don’t be stubborn about the ISO, for stuff like this bump up the shutter speed, you’ll get better images that way!

On the plus side, I can now state that I have seen, personally and with my own eyes directly, with binoculars, or with a telescope all but one of the planets. The only one I’m not able to say I’ve seen with 100% confidence now is blue Neptune. Pluto doesn’t count, even though I keep thinking of it as a planet. Plus Pluto is so far away that I’ve got a snowball’s chance in hell of seeing it in person. Mercury, Venus, Earth, Mars, some asteroids, Jupiter, Saturn, and Uranus I’ve all seen now. Hold the Uranus jokes, please. Maybe this year or next year I’ll bag Neptune as well.

With Neptune having a magnitude of 7 to 8, I think I now have the necessary tools to locate it. I just have to watch for it to pass near something I can easily identify in the night sky and triangulate off, something that will help me restrict the area I search. The setting circles on my Celestron Classic C8 should really help with this hunt as will the GoTo capability of my Celestron Nexstar 102GT. Provided, of course, that I orient them properly.

Speaking of the Celestron Classic C8, I have the piggyback mount attached to the OTA (Optical Tube Assembly) now. This will let me mount my camera on the C8 and use the telescope to guide the camera. I should be able to get some nice long exposures even with the 400mm now.

General Photography

The only time I did any intential photography in this period was while on vacation in McCall, Idaho. As usual, we went to Charlie’s Gardens to see it and myself with the intent of doing some photography.

This time I got some really nice images of various flowers, and I admit to being pleased with many of them. I was trying to do macro flower photography and I actually took several hundred pictures. Some I took to try and stack for a greater depth of field and some I took to try different perspectives. The best ones, though, were those I simply took to practice macro photography.

Picture of a small blue and yellow flower against a blurred background of green leaves.

A macro of one of the flowers at Charlie’s Gardens, McCall, Idaho.

I also attempted to take the necessary pictures to produce a multiple image of each granddaughter, of my daughter and her daughters, and of her husband. For various reasons that I fully understand in hindsight, the results were dismal: late in the afternoon the light was changing too rapidly, and my depth of field was too shallow. Of the six shots in each sequence, only one is really in focus, the rest are just out of focus. Perhaps not enough to matter to others, but to me that whole project should be tossed. I’ll probably still assemble the images and deliver them to my daughter, but I’m definitely neither happy with nor proud of the result.

Amateur Radio

I’ve done no operating, but I did manage to get a nice, clean installation of my Yaesu FT2500M and FT857D radios in my new to me 1992 Blazer. Power and feedlines are mostly out of sight and are definitely not in the way of passengers or driver like they were in the Geo Tracker.

Image shows two radios mounted in the center area of a 1992 Blazer Silverado.

The FT-2500M is mounted right under the dash while the FT-857D is mounted to a bracket that is in turn mounted to the sloping front of the center console. The Chorus (described in text later) is in the console cupholder.

Antennae for 2m and 70cm are roof-mounted mag mounts: a 5/9 whip for the FT2500M and a combo 2m/70cm for the FT857D. For a clean HF antenna mount, I bolted a front receiver to the frame of the Blazer and was thus able to simply slide in my stinger-mounted 40m Hamstick, using the entire mast assembly intact from the Geo Tracker. I was even able to keep the tow hook that was there. I couldn’t use the rear receiver as the antenna would constantly be in the way of opening the rear and there’s also the need to use the rear receiver for towing the trailer.

This shows the receiver mounted where the tow hook bolts on as well. The L shaped receiver with the condujit pipe mast is the same assembly formerly used in my rear receiver of the Geo Tracker.

This shows the receiver mounted where the tow hook bolts on as well. The L shaped receiver with the conduit pipe mast is the same assembly formerly used in my rear receiver of the Geo Tracker. The mast has no noticeable impact on the headlights lighting up the road.

There’s no APRS install yet as I’ve got to figure out where to put the GPS receiver for best reception. I don’t want it just sitting there on the dash against the windshield. The Geo Tracker’s ragtop was ideal for the APRS setup I had. The Blazer has a metal roof, as you’ve probably deduced from the use of the mag mounts, so mounting it right up there against the roof isn’t an option. I’m thinking of mounting it to the Blazer’s roof rack, but we’ll see.

I also found a small device, the Chorus in the cupholder of the interior image above, that I had forgotten about. That device was originally intended to help me with lipreading but it’s useful for other audio detecting. Supporting a vibrating external transducer and having a mic input, it allows me to connect it to the radio’s audio jack and feel when the squelch breaks without having to look at the radio. I’m hoping it will help me locate and identify CW frequencies in the area. I’m also hoping that with it I’ll be able to eventually learn to “listen” to CW by feel.

Along with that approach, I’ve got a friend attempting to recreate an arm-mounted device I read about that was only referred to as “the Thumper” by some deaf CW operators back in the 1960s. I’ve mentioned the Thumper in an older post.

One of the things I’d been trying to figure out how to do recently was to somehow limit the FT857D scanning to just the 40m CW frequencies. I finally found out it has that capability in the form of Programmable Memory Scanning. Yes, the manual does refer to it as PMS, and so does the radio’s LCD: “press the [C] (PMS) key”. I’ve already made some groaner jokes about that elsewhere and won’t repeat them here. Anyway, it goes to show checking the owner’s manual every so often is worthwhile.

I’m hoping to use this feature to monitor for CW activity without having to scan through all the other frequencies I’ve got programmed into the FT-857D. I’ll be doing this monitoring mostly during my commutes to and from work but hope to also play with it up in the Owyhees. With any luck, eventually I’ll build up a list of reliable CW frequencies for this area and start imporving my CW skills.

I have no intention of transmitting CW while driving. I’ll pull over to operate, but I very much want to get my CW skills up and running so I can have reasonable QSOs and be able to just “listen” to CW exchanges while driving like you listen to the AM/FM radio or your cell phone. I’m not into contesting, but I am interested in chatting and this is a skill that would be very welcome during my Owyhee explorations, which often are in areas with no cell phone service.

That’s it for now. I’ll try and post more frequently again.

New Scope and Moon

12 March 2014

We finally had a nice weekend with clear skies. I have just added a Celestron Classic C8 to my telescope “collection.” I’ve used this particular telescope several times in the past and always admired it. Apparently, I’m the only one that has used it over the last few years because I no longer have to borrow it, it’s mine now.

So, of course I’m antsy and want to get it outside and check it out to make sure everything’s in place and doesn’t need adjusting. With last Friday being nice and clear that’s exactly what I did.

The feature I was most curious about and eager to test is the ability to attach my camera to the telescope. It came with the T-back and I had the T-ring for my camera. I was hoping not to need to use a Barlow or my T-adapter. In theory I shouldn’t need it, but I just didn’t know.

With the night so clear and nice, I quickly assembled the telescope and had it ready to go. The Pentax attached just fine to the tube and it was a mere 5 minutes to attach the wedge to the tripod and the telescope to the wedge. This night I elected not to use the clock drive but rather to direct it manually. I also did not align the scope on Polaris. The goal, after all, was to just check things out.

Image of the viewing end of a Celestron orange Schmidt-Cassegrain 8" telescope with a Pentax K-10D DSLR mounted where the eyepiece would normally be.

My Pentax K-10D installed on the Celestron Classic C8 using a T-ring and the telescope’s T-Back.

I’d forgotten that my Pentax K-10 only records up to a 800mm lens in the EXIF data. So, the pictures I took all say the focal length is 800mm and don’t show the f-stop. In this setup, the C8 becomes a 2000mm f/10 prime telephoto.

The first target was the most obvious: Luna, Queen of the Night.

It was immediately noticeable that the finder scope was off to one side. With the moon centered in the crosshairs, She was not visible in the viewfinder of the camera. There was an apparent faint glow off to one side, so I moved the telescope that way. Almost immediately, the viewfinder filled with a soft white light, obviously the moon. For a couple of seconds I was disappointed before I remembered I had yet to focus the image in the main tube. It didn’t take much adjustment to bring the moon into focus, and it was a beauty. I just enjoyed the sight for a while, almost forgetting that I had the camera attached and not an eyepiece.

I played with the focus a little, trying for the best possible view. The camera was already on manual mode, so I checked the ISO, set the shutter to a 2 second delay, and adjusted the shutter speed. Setting the shutter to a 2 second delay gave the system two seconds after the shutter was released to let any vibrations die out before actually recording the image. I had hoped to set the f-stop manually but was unable to, which actually is normal for a fully manual lens on this camera. The camera has no way to tell what the aperture is, so it refuses to let you set anything there. Adjustments to update the EXIF will have to be done after the fact, which is easy enough to do.

With everything set to my satisfaction, I began taking pictures, adjusting the shutter speed for each shot and checking in the display. For each shot I would move the telescope to lead the moon slightly, then press the remote shutter.

Image of a half-moon taken through the C8 telescope with the Pentax K-10D

The moon taken through the Celestron Classic C8. I love how it fills the entire viewfinder.

This worked well because there was enough reflected light from the moon that I could utilize high enough shutter speeds to freeze the moon’s motion. No tracking was necessary.

So far, everything was working well. There were only two issues that I could see. The first was the misaligned spotter scope. An easy enough fix and one I’ll take care of soon. The other is more a use issue than real problem. Even then, it’s only an astrophotography problem and not a viewing issue since when simply observing I can use the right angle adapter for the eyepiece. That night, the moon was up high, almost overhead, and that makes it a little hard to get a good view through the camera. That’s one reason the spotter scope has got to be aligned.

Satisfied with all this, I turned my eyes to M42, the Great Nebula in Orion.

It was just visible, even with all the light pollution in my driveway. I decided to try some camera shots just to see what would come out.

I’ve taken shots of the night sky before, and even have images with a fairly decent Milky Way and very little star trails. I even got this nice shot of M42 with just an 11mm lens on the camera. I’d forgotten, though, just how narrow the field of view for a 2000mm would be. Even though I used the least possible amount of shutter speed, I could not avoid very noticeable star trails. That, of course, made the nebula itself impossible to see in the resulting photos. It was also a good reminder how little of the sky would actually be in the image.

Happily, I also have the piggyback mount so I can attach my camera to the top of the telescope and hopefully use my 200mm and 400mm prime lenses for some deep space photos. For this type of astrophotography I’m going to need the telescope tracking and that is actually one of the reasons I’m so happy to have this scope. I look forward to seeing how this turns out.

Yes, my Celestron 102GT does have NexStar guidance, but it does not yet have an easy way to mount the camera on it. However, given all the control I have for it, as indicated in this blog post, it may be that I will mount the camera on the tripod in place of the telescope and use the NexStar guidance/Stellarium control to do my astrophotography tracking while I use the C8 to enjoy the night skies at the same time. I just have to build a camera bracket first.

All in all, I am every bit as pleased with the Celestron Classic C8 as I expected to be. Before I use it again, you can bet I’ll have the spotter scope zeroed in and the piggyback mount installed.