theropod

A tiny meteor, or satellite flare. Comets have a distinct head, or nucleus, and almost always a tail streaming away opposite the sun. Sometimes a dust tail and an ion tail. That’s my call anyway. rS

Well, yes, but my god man look at that grainy result! I’m sick about it. It took me quite a while to learn how to get a shot like the Orion meteor example, and the idea of having to go through all that again is daunting to say the least. I’ve never even held a DSLR in my life, and settling on one out of the thousands out there is going to be a nightmare in itself. Maybe I should just go on fleaBay and find an old iPhone 6. Naw, I need to go ahead and plunge in, bite the bullet, take the next step, go all in, shoot the moon and figure out which DSLR fits my budget and actually works.

Here is a shot from a couple years ago. Tracked, 5 minutes. Last night in an attempt to grab Neowise, and this is the best of dozens of shots. Tracked, less than 3 minutes. Edit to add: The streak on the right is a meteor that I witnessed. Had I my old camera/phone I would have grabbed one of those once in a lifetime shots. No, nothing frustrating here.

Slightly off topic, but yeah it’s so easy. Last fall my trusty iPhone 6 plus died. No biggie, AT&T insurance replaced it in a week, but they didn’t. They sent me a refurbished 6s plus. The newer phone has a 12 mega pixel camera with software limits on shutter open time and artificial f stop. My older phone had an 8 mega pixel camera and had far more flexibility in regard to the f stop and open shutter time. Both phones are/were running the low light app NighCap Camera, and my main interests lean toward meteor falls captured in tracked long exposure wide field shots. The newer phone has completely failed to register small meteors, and fainter stars, the old phone would have grabbed like a nail by a rare earth magnet. Side by side photos are consistently worse from the newer phone. I exchanged several emails with the app developer. Sent him photos from old phone and newer one where both were supposed to be the same in every way. It took us two weeks to figure out what was going on. He may write a patch, but Apple has to approve EVERYTHING. The above leans into the topic in that my notes and settings no longer work, and to even register an image at all I have to crank the ISO more than 200% higher than previously used. This induces noise on a logarithmic scale. If I use lower setting I must extend the exposure time, and noise creeps in the longer the shot. Also the newer phone suffers from sensor heating, and the shots become vignetted with edges getting washed out. I used to be able to capture mere sparks of meteors, and now a fireball would look like a muddy streak. I used to be able to take 10 minute shots with a velvet black background and pinpoint stars, and now the darkest night shots are gray with little smudges where stars should be. Oh well, I’ve been looking for a DSLR for a few years, and have an absolute stack of old film type Canon lenses. I understand that these old lenses, one of which is a top shelf telephoto, can be used in astrophotography. I’d get better results, but spend the rest of this summer learning everything all over again. Sigh... Nope, nothing hard about this at all. I think I’ll take up repairing microchips next.

How about screen secured to a hoop of the right size? I’d use 80 mesh count polyester screen printing screen, and two part adhesive to secure it to the hoop. That’s plenty enough gap for good air flow and still be small enough to keep most of the nasties away from that all important primary.

North Arkansas here. Otherwise known as cloud heaven.

Here is a Perseid (and airplane headed to Memphis, TN) fall from 4 years ago using the SkyTracker. This is a 5 minute exposure, and I hadn’t learned how to fine tune the alignment yet. Taken with my iPhone 6 plus with no editing whatsoever. I have picts with perfect stars, but no meteors this nice. I’m seriously considering a nice DSLR to use in my meteor hunts. The iPhone does the job, but just barely, and then only running NightCap Camera app. On hot summer nights the noise can go through the roof. I see picts with the core of the Milky Way and lust.

No to both. However a counterweight can be DIY’ed pretty easily. Replace the stock brass 1/4” X 20 threaded mounting stud with a longer steel bolt. A securing nut is then placed atop the channel, then an oversized flat washer and finally the ball head (or other scope mounting system). A stiff steel channel like used for drawer slides drilled and mated to the new bolt at the padded flat of the tracker. A set of “Vise Grip” locking pliers can then clamp down something/anything to the channel, and be moved in/out as needed. If I find a need for such this is my plan of action. The big problem will be balance as the circular mounting pad where the mounting bolt protrudes is not clutched in any way. 2 small screws lock the pad to the tracker, and the iOptron counterweight system provides a third similar screw to make the attached bar/weight more robust. Even then there will be balancing issues as these screws are all that connect the padded part to the main drive spindle, and not locked down will spin oddly and not true. The mount is actually intended for a DSLR with a modest lens. When kept well under its load limit it tracks very well. It’s simple to polar align, and the illuminated alignment scope is clear and crisp with focus adjusting. With just my iPhone 6 plus my widefield shots are superb when I nail down alignment. As I wrote before mounting my C-90 Mak is about all the mount can handle. Counterweight(s) wouldn’t correct the issues I have in this regard. If you need a scope mount I would look at a more robust mount as these are mainly just trackers. Great little trackers, but not designed to carry a scope of substance. This is why I’m about to order the CEM25P. Hope this helps.

I have the iOptron SkyTracker Pro, and love it. I have mounted my C-90 Mak on it via a ball head, but it isn’t fun. The scope is just a tad heavy, but this doesn’t effect tracking accuracy. The not fun part is getting the target locked into the center of the FOV, and not upsetting polar alignment. It takes two or three adjustments to get the target centered and alignment set. I use a heavy duty transit level tripod made by Bosch modified slightly to lock down the tracker base, and that part is rock steady. I’m not into the DSO/planetary photography side, but have watched Jupiter for hours with this setup. It’s so tough to get things right switching targets isn’t done on a whim. However when I mount my phone to capture meteors I can get 20 minute exposures with nice round stars, but this requires really nailing down that alignment. The little scope and app from iOptron make that fairly easy. The tracker just shifts alignment a little with a load when fiddling with targeting, and needs to be corrected. I am about to pull the trigger on an iOptron CEM25P, which should turn the whole ordeal into a pleasure. I’ll still use the little tracker, but just to capture meteor falls. I’m sold on iOptron mechanics. My tracker is 4 years old, and the battery can run the mount all night and then some.

Any hardware store should have a similar dot level one could place on a flat spot on the mount and leave the faulty one in place. I would lean toward keeping the little level in my pocket and only use it during setup. Of course iOptron may choose to replace the whole mount.

Magazine cover quality!

I have a nice little scope, and enjoy looking at stuff “way out there”, but my thing is wide field work. Mainly I try to photo meteor falls. A few nights ago I was reclining in my lawn lounger when I picked up, by eye, a string of Elon’s playthings. From the time I started counting them until the apparent last one past 21 clones crossed the exact same path. They were about 13 seconds apart as my best guess from nearly occulting some bright star. Their speed suggests a very low orbit as these little dots were fast. Little as the dots were they were bright. I checked the time and it was almost 11 pm. Naturally my tracker and phone were pointed wrong (or right to miss) to capture the little abominations, which is just as well. I’m sure there will soon be a time when I cannot point at any segment of the sky and expect a streak free shot, and those faint speck meteors will be very hard to pick out.

Scitmon has given you the best advice possible. Learn drift alignment and never look back.

Is there a plain 3.3v version without the other stuff?

How? Because the step pulse is all you need, and no I’m not using your driver, and I’ve made it VERY clear I’m using a NANO. I have also made it clear that your Uno and a Nano function exactly the same pin for pin. All your driver needs from the Arduino (Uno, Nano, whatever) is a stream of pulses. You can set the direction, and enable, via the 5v pin regulated output pin on the Arduino through simple DIP switches, or push buttons, that have nothing at all to do with programming. This leaves those output pins free for other chores, or keeps the code super simple. I was asked to post my code. I did. I explained how those signals for direction and enable are provided externally to the Arduino. I just don’t think you understand what you’re looking at, and I’m not able to explain this well. 95% of the time your barn door will be turning one direction, so to why complicate the code with crap that has no effect on the barn door? Turning the drive motor backwards by hand doesn’t take very long as I can spin mine back to the start position in under 2 minutes. No big deal for every 3 hours of run time. If you set up a simple momentary push button switch even reverse direction could be done if you wanted it. Those signals DO NOT have to come from the Arduino!! I’ve repeatedly mentioned my using Easy Drivers, but your driver works almost exactly the same way. All the Arduino needs to do is pulse the step signal to the driver, and you control the direction and enable via switches. If you’re looking for someone to match your equipment part for part AND write code just for your situation I don’t know what to tell you. Never mind. I must be failing in spades to make, what to me is a simple matter, clear. If what you have is working, good enough. I really don’t know what more you expect. I was merely trying to help. I’ve spent my last drop of energy on this matter. Good luck with your efforts.

Most stepper motor drivers can be set to direction without the need to use up a processor output pin. If the driver needs to see positive voltage on a direction pin it’s easy enough to supply it via a DIP switch. The same is true if it expects to see ground. My Easy Driver defaults to one direction without input, and reversing the motor leads controls direction. I still provide that direction pin 5v positive from the Arduino. My design is manual reversing, but adding one output pin and enabling the function in the Arduino sketch is super easy. See my post about my home made alt/az mount. Steppers are super easy. ETA: link to alt/az project.

It might be easier to incorporate an incline sensor than to attempt to vary the step speed based on time. The 3 axis gyro chips on breakout boards would probably work in such an application. It should be relatively easy to detect the rate of increase in the angle and force the step pulses to match an ideal. This would, of course, require a big jump in the complexity of the code, but should be doable. I would think such an approach would require a good deal of fine tuning and altering the code several times. I feel a simple encoder would be easier to fold into the design, and give constant precise results. I don’t think one would need a high value encoder to make this work either.

After checking the specs for an Uno the sketch will work exactly the same as if running on a Nano. The onboard LED is tied to D13 for both Arduinos. Try loading my sketch on to your Uno, hook it up to your drive and see what happens. You can load new sketches on an Arduino thousands of times, so if you don’t like the way it works it’s simple enough to ditch it. The use of the millis function provides much more precise timing than using the delay function. When the delay function is called the Arduino comes to a complete halt. Nothing happens at all until the designated end of the delay. With millis the Arduino only has to keep track of how much time has elapsed. Only folding in a Real Time Clock would increase the accuracy of these timed events, and maybe incorporating an encoder to use interrupt events as precise feedback. Both of this things would add a great deal of complexity to the software/hardware, and with complexity comes headaches. Not that these things can’t be done, indeed I’ve dreamed of just such a barn door tracker. What I have now works flawlessly, and consistently. I think someone ought to make these commercially available, and include the features I cite above. If someone could come up with a way to mount these things on any good tripod, be accurate over 10 minutes and have a really good built-in polar scope I’m sure they would sell. Heck, kits would be great for families!

Is there something about the code I posted over in the other thread that troubles you? If your driver accepts a simple pulse stream (which it does) that code will work perfectly. One numeric value in one line of code, which I made clear in the comments, is all that’s needed to adjust the speed to suit your needs. The numerical value doesn’t have to be a whole number either as decimal fractions work just fine. Frankly I find it odd you would start another thread when your answer has already been provided, and ALL the programming done from a working example. Is there something I’m missing here?

Yes, and when a triplet f3 was suggested... I don’t think doing this would be so much complicated, as expensive. Integration of the images is done now with panoramic shots standard to iPhones. Once the data was created images could be projected anywhere that had a large enough data pipe. Really good all sky captures could allow any of us to sleep under the Atacama sky, live, in our our bedrooms. Technology is probably in the works by someone with coins to spend to do this very thing right now, if it hasn’t already been brought to fruition.

I bored a nylon block to 1/32” larger than my drive rod (1/4“ x 20) and mounted it on a pivot to act as a guide. The nylon bushing keeps the drive rod registered with the gear and hinge point. This pivot is two short sections of VCR tape read motor shafts epoxied to 90° x 1” angle aluminum. This is fixed on the under side of the stationary/barn plate. The bearings that supported the motor shafts in life now keep the shafts free to turn and follow the imperfections in my bend. A cross drilling through the nylon block at 90° to the drive rod hole with a tight fit to the VCR motor shafts, and a drop of super glue, and the nylon block is a very low friction guide. I let my angled aluminum float until I found a point where there was the lest friction by opening and closing the tracker and clamping those bearing angle pieces in a best guess position. This keeps that rod at a “just so” distance from the hinge even if there are uneven spots. No lube is needed on the nylon, and a drop of light oil on each bearing twice a year keeps things smooth. I will try to remember to snap a photo tomorrow. OFF TOPIC WARNING: I am restoring my 92 Ford Ranger 4X4, and have poured some coins into a stem to stern servicing. The front end in total was rebuilt. New tires, shocks, brakes, exhaust, 30 over bored, crank turned 10, new head yadda yadda yadda. Today I figured out 2, maybe 3, of the injectors are working part time. On that 2.3 Lima the whole upper half of the intake has to come off to get at the little devils. I should have put a new set in when putting the engine back together. Live and learn, or maybe not... I’ll get a photo if I’m not distracted by a stumbling old truck

Be aware that “my” code was set up for a Nano, and the onboard LED pin (D13) is used. A different Arduino might need a different designation here. Any digital pin should work just as well, but I used that to provide a visual indicator of pulse timing via the blinking LED. In the dark this flashing LED is a quick and easy way to know your tracker is doing its thing. My ban door tracker needed several adjustments to the baseline timing, and along with drift alignment it’s surprisingly accurate. Yes, it took several nights to get it right. 5 minute wide field exposures yield nice round stars, and since my thing is trying to catch meteor falls this is good enough for me. I have mounted my C-90 Mak on it via a ball head, and it keeps a target pretty much centered in the FOV for the 3 hour length/duration of the curved all thread rod. I use a spring loaded (an elastic hair scrunchy) setup on my stepper motor to hold the drive gear firmly in contact with the driven gear on the bent rod. Both gears were salvaged from a dead VCR. While plastic they seem to hold up well. I have left the base outside for nearly three years now, and I see no degradation so far. I just remove the stepper, and Arduino, and let the rest of the tracker sit. Mine is mounted onto a plastic 55 gallon drum filled with water. Of course a brass gear set would be better. I epoxied the small gear to a belt pulley on the stepper, and to the nut that rides on the drive rod. When the bent rod is used up I simply push the stepper away and spin the tracker gear backwards to the starting position. This only takes a minute or so. Had I put more effort into the little device, like a retainer for the driven gear so it wouldn’t creep up the drive rod, a simple pushbutton switch could reverse the motor at a much higher speed. Frankly I didn’t think it worth the effort.

Science isn’t in the business of “proving” anything, and to label a mass of empirical evidence as speculation is at best an ignorant statement. Individually we do lack the intellect to assess the issue, but collectively we can grasp such things, and this is the way science works. By examinations from several avenues of study we gain a conciliatory view of observational reality, and the resultant conglomerate of facts provide us the most accurate framework developed to date. It is very easy to dismiss this body of work out of hand, but far harder to refute. Until such time as the existing evidence that there indeed was an inflationary period in the history of our universe is overturned it is only logical to accept what the evidence tells us. The cosmic background radiation isn’t a dreamed up “just so” story. The earliest galaxies spectroscopy data doesn’t return consistent results because the researchers “needed” it to. As for the “just a theory” position it’s clear that such arises from a laypersons understanding of matters of science. Is the germ theory of disease “just a theory”? How about the theory of relativity that resulted in the discovery of light being distorted by gravitational masses? A theory is the explanatory framework used to describe observations and positive test results. A theory has also survived each an every test put to it, and a means of falsifying the base premise of the theory if condition X arises is provided. A hypothesis, alternatively, is a suggestion for a new position whereby testing and a means of falsifying said position is put forward.

The code is just a revamp of the “Blink Without Delay” example provided in the Arduino IDE package. I lied. There are 19 lines, but 3 of those are just ending statement curly brackets. The end user will have to alter the baseline timing number to fit their final drive gear ratio, but it’s clear where this number is and how altering it effects the stepper motor speed. Code below: const int ledPin = 13; // the number of the LED pin int ledState = LOW; // ledState used to set the LED to off or step pulse to off unsigned long previousMillis = 0; // will store last time LED was updated const long interval = 50; // adjust numerical value to suit your needs larger number equals slower pulses void setup() { // set the digital pin as output: pinMode(ledPin, OUTPUT); } void loop() { unsigned long currentMillis = millis(); if (currentMillis - previousMillis >= interval) { // save the last time you blinked the LED previousMillis = currentMillis; // if the LED is off turn it on and vice-versa: if (ledState == LOW) { //if step pin signal is off ledState = HIGH; // turn it on } else { ledState = LOW; // if the step/LED pin is high then turn it off } // set the LED with the ledState of the variable: digitalWrite(ledPin, ledState); // sends the signal depending on the state of the pin. } }