Posts Tagged ‘photo’

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.

Advertisements

A Return to Stereograms

4 April 2018

I have mentioned working on stereograms previously. These last couple of weeks have seen me focused on them.

Stereogram created from drone video taken at Wickahoney. See text for details.

Most that I have done before are close-ups, if you will, or portrait oriented.

I wanted to play with stereograms some more, this time focusing on landscapes. My goals were, first, to get them working consistently and second to hopefully work out any rules unique to stereograms.

In my mind’s eye, I remember sitting on the floor at my grandparent’s with a big box of stereograms and a now antique viewer. I would pick out a card with it’s two slides, read the caption, drop it in the holder, and clap the stereoscope to my face. I remember being fascinated how I could see a 3D version of a scene and how it contrasted from the pictures on the wall.

More, I remember most of them were landscapes.

Now, I’ll grant you my memories of those images are likely rose colored by time and they may not have been as fantastically 3D as I seem to remember. Most indubitably, though, there were hundreds of landscapes and not so many of flowers, people, or objects.

My goal in this recent project was to create valid 3D landscape stereograms. I also needed to work out what the limitations were, and how best to create a pleasing image that was also 3D.

Like this one:

One of the spots that overlooks Swan Falls and the Snake River Canyon, looking downstream from the dam.

Or this one, where the red rock formation just pops out at you:

Looking at Swan Falls Dam and the Snake River Canyon. The red rock is very prominent in the foreground.

What are the rules?

Aside from standard landscape photography composition “rules” I felt there must be some additional guidelines that would drive the composition.

As it turns out, there are, and there aren’t.

One of the things that you need to keep in mind when creating stereograms is:

  1. Take a picture of your subject. Remember where the center of your picture is on the subject.
  2. Take a step to the left. I usually stand with my feet just more than shoulder width apart. After taking the first picture, I move my right foot to touch my left foot then move the left foot so I am again standing with feet apart.
  3. Aim the camera at the exact same point on the subject as before.
  4. Take another picture.

That is my way of getting paired, handheld pictures. The first picture taken thus becomes the “right” picture (as in taken from the right) and the second becomes the “left” picture. The key to assembling the stereogram is the right picture goes on the left side and the left picture goes on the right side.

You can, of course, do it stepping to the left instead. In this case the first image becomes the left picture and the second becomes the right picture. No biggie, just get into the habit of doing it the same way each time.

There’s times a question arises whether or not the middle and far parts of the photograph actually show as 3D. Sometimes they do, sometimes they don’t. Sometimes they work if you have some decent foreground detail, other times you don’t need that foreground to make it work.

Willow Creek, off Black’s Creek Road. Notice the apparent differences in 3D impact in this compared to the Swan Falls stereograms.

And then, there’s the issue of anything that’s moving…that’s likely to produce “ghosts”, faint or translucent objects in the photo. Your main scene, the one you want to see in 3D, has to be still. Trees moving in the wind, clouds passing by overhead, cars on the road, people moving…all those and more need to be avoided.

One way to avoid natural movements such as clouds and water ripples is to use a long exposure time. That way, things get “smudged” smooth. Ripples on water, for example, become a soft flat surface and clouds become featureless.

Interestingly enough, I have one stereogram (below) where the two angles are such that one shows the parked truck and the other doesn’t, and yet the truck is solid in the stereogram view. It’s not a translucent ghost due to being in only one of the paired images. Yet another stereogram I’ve done freezes a car in one picture but it’s not in the other and this time it shows as a ghost car. Go figure. That’s what I mean about “there are and there aren’t additional guidelines.” More likely I haven’t figured them out yet.

Notice how the black truck is in one image but not the other, yet still comes through in the stereogram as solid, not as a ghost image.

By the way, the Wickahoney stereograms were all pulled from a video created by orbiting my DJI Phantom 4 around the midpoint of the ruins. You do remember that a video is merely a string of still images played back rapidly? Each pair, in this case, were pulled from about 1 second apart, e.g. one would be from 13 seconds into the video, and the second of the pair would be from 14 seconds into the video. When doing this, creating a stereogram from a video, you want to be sure the video still image isn’t blurry due to the drone moving too fast, to continue this example.

Stereogram from Wickahoney drone video.

One thing I did discover is that if you use a zoom or telephoto lens to enlarge something in the distance and make it part of your foreground or the middle distance in the photograph, you have to displace the camera location much more than a single step to one side. A problem I encountered was I could properly displace the distant solitary tree but the mountains behind it shifted significantly. They shifted enough that even though I could get the tree to be reasonably 3D, the more distant mountains were blurry.

A wide angle lens, though, works great and lets you really bring in some foreground:

Snake River Canyon from an overlook at Swan Falls, looking upriver from the dam.

And that’s as far as I’ve got. I’ll be going out and shooting more landscapes, as well as some closer subjects.

I think I know how to apply this technique to video as well and plan to try it with the video used to make the above Wickahoney stereograms. That’s for another time, though.

A Return Update

5 March 2015

It has been a weird beginning to the year for me.

I fully meant to return to this blog well before now, but somehow writing for my blog just wasn’t a priority. From time to time, I’d think of something to write about, but I just never sat down and actually did so.

From an amateur radio standpoint, I’ve been working to develop something I refer to as The Thumper. It’s based on something I read about in a blog post where the ham described his fondness for CW (Continuous Wave, aka Morse Code) and an on-the-air experience meeting a group of deaf learning ham radio and cw. The original Thumper was mentioned only in passing, and described as “a device that attaches to their forearm and taps them to indicate the Mose Code being received.” I have various issues with LED displays and my current tactile transducer setup leaves much to be desired. For The Thumper, I’d started by utilizing an Arduino driving a RC servo and while that does work to an extent, it has an inherent speed limitation that I don’t like. Almost anything over 10 wpm keeps the servo at the end of travel, making it impossible to detect the characters. I’m now looking at using a vibrator similar to those in cell phones, compliments of a good friend and fellow ham. Although not what I originally envisaged the vibrator does show better promise and a nice theoretical response to faster CW speeds. Coupled with a LED, it may turn out to be the best solution for me to listen to the radio. I know, but the combination might turn out to be better than the parts. Right now, I’ve only got the Arduino driving the vibrator. Still to be done is receiving and converting over-the-air CW signals provided via the audio jack of my radios.

Plans are under way for more Owyhee explorations, and while doing that I fully intend to try HF radio work from way out in the middle of nowhere. I’m building an end-fed, multi-band wire antenna that should be tuned to each band: 10m, 20m, 40m, and 60m. It’s only mobile in that you can easily carry it coiled up in the vehicle, to use it you have to park and deploy it. We’ll see how that works in practice, but I’ve got good expectations. I’ll be focusing, of course, on CW and PSK but when solo. If I have a friend along, I’ll be trying some phone work as well. More than likely, I’ll be band scanning and if I hear anything, I’ll pause on that and see if I can contact the other person.

Photography-wise, I’m currently teaching a beginning photo class, but with a twist. In all my previous classes I noticed that there was never a deaf or hard-of-hearing person attending. This time, I told the community education group that I would teach a beginning class in sign language. When I shared this idea with the few deaf community members I knew, the enthusiasm was outstanding. In the end, due to various reasons, there were only three in my class. We’re having a blast and there would have been at least two more were it not for an age limitation posted on the community education web page. That limitation didn’t apply to my class, but that exemption information was not passed on to the people that wanted to sign up. Word’s starting to get out there about this class, though, and I’ve mentioned I’ll offer it again, the same way. One of the reasons for doing this is that I just felt like turning the tables on the regular offerings…they’re oriented towards hearing people, the deaf have to get an interpreter. This time, though, it’s the hearing that have to get an interpreter if they try to attend.

I have also been investigating the use of the Shutterbug Remote with my Pentax K3 DSLR. Testing with an iOS device showed that the remote works well with the K3, but I’m getting crashes using the Android version of the app on my Samsung Galaxy Note 4. Testing with a Samsung Galaxy S5 shows it works reasonably well with that phone, so now I’m trying to determine whether or not it’s a setting, a FW, or a HW issue with my Note 4. An email to the developers has not provided any response, so I’m very unimpressed with the customer service aspect of their website. Enough that I’m not providing a link to it. It would be really nice to get this remote working with my phone as it’s a great little device which when used as an intervalometer provides better timing control capabilities than the built-in intervalometer mode of the K3. If I can’t get it working, I’ll definitely have to create an Arduino intervalometer or something.

I’ve built a new woodworking bench (above) in my garage along with a DIY woodworking bench vise (below). These will come in handy when I start building the Vardo.

On the Vardo front, I’ve started gathering materials to modify the trailer for the Vardo. It took me a while to figure out the best way to use my flatbed trailer for the Vardo, and still be able to easily use it as a flatbed trailer. One of the things I had to deal with was me being “greedy.” The flatbed trailer is 12’ by 6’ and I had been doing my designing based on that entire area.

Image of a 6 foot by 12 foot utility trailer with one pair of wheels. Sides are an open framework of angled metal. Tail gate is about 4 feet tall when up and contains a metal mesh. Parked next to a blue-green 1992 Chevy Blazer in front of the garage in the driveway.

This is the new utility trailer that will become the base for the Vardo. I’m especially happy to get the all metal bed.

I was going to have a big Vardo that had luxurious room inside. Kind of a contradiction to my original plans for a simple, cozy Vardo, actually. As a result, one of the things I had to figure out a way around was the six tie-downs on the trailer bed near the sides. I finally realized that they provided a perfect way to fastend the Vardo to the trailer, a la pickup campers: straps built onto the framework of the Vardo that connect to the trailer tie-downs via turnbuckles. To do that meant I had to narrow the width of the Vardo box to fit inside the tie-downs enough that I could hook them into place and tighten. It’s only a 6” loss in width, give or take, but it also freed up the solution to another issue: I wanted to put the same kind of mesh that I had on the tailgate along the sides of the trailer. That way, things put in the trailer wouldn’t roll out under the existing side rails. And I could use that now open area to store poles for awnings, and other such gear.

I’ve been doing quite a bit of fishing lately, for rainbow trout. Normally I would catch and release trout, but my wife and I have found that we like the fish. I’ve learned to fillet them so that we don’t really need to worry overmuch about bones while eating. Only about 15 minutes from my house is a great little pond where, so far, I’ve always managed to catch my limit every day. I didn’t use to fish that much, or to enjoy it, but I’m finding I do. I’ll probably go fishing rather regularly while retired, using that to supplement our diet with fresh fish on a regular basis. It’ll be interesting to see how the fishing goes as the weather warms up.