Astrophotography - Tripods vs Motorized Mounts

a reply to: intergalactic fire

Ha, looks like we cross posted!



Yah, my biggest mistake was: forgetting I was using a CCD camera.

Which is funny, because I remember going out and buy the CCD Camera Cookbook when it first came out in the 1990s, for building your own homemade CCD camera for telescopes.

Thermal noise was the biggest issue because when a semiconductor conducts electricity, part of that energy becomes heat, because: semiconductor is not a superconductor, and so resists current, which changes electricity to heat (and why electric stoves and heaters heating elements get HOT).

Lots of designs using a pellter chip for cooling, air cooling, ice cooling, liquid cooling were in the book. Of course technology has gotten much, much better since then, and is why you do not need to pack your DSLR camera in ice to take a 3 or 4 minute exposure. My camera wouldn't like that very much, hehehehehe.

As long as the weather holds out, and it's looking like it will, I'll try again tonight, using the shorter exposure methods, and then stacking them.

Right now I'm using Registax 6 as my stacking software, cause it's free. I wanted to get a different one, but it's $190.00 for it, blllaaaaah.

originally posted by: ThePeaceMaker
a reply to: imitator
Nice work ! I'm actually pleased you went out and attempted it. 88 shots? Once you've got the idea and begin learning what settings I guarantee the shot count will go down as you begin to getting better pictures straight away
Keep up the good work!

Yes 88 shots haha.... it took a bit for me to figure out the settings, also some of the shots are terrible and grainy, but I think I've got it down now.

I was reading eriktheawful software thread. www.abovetopsecret.com... so I looked up software for my camera and found CHDK... dun dun dunnnn.... I now can extend the exposure and ISO etc. also found a intervalometer script so I could take 100's of shots of the same area of sky without pushing a button... now I could build a motorized tracking mount!

Glad I never sold this cheap camera.

I've been meaning to get out more as well but the weather here in the UK, well for my area is meant to be overcast for the next few days

Ah the UK... I hear you guys don't get much sunshine. In Texas, we get to much sunshine, but this time of year is when our storms start.... all of next week will be wet and cloudy.

I think tonight I will use the intervalometer and see if I can catch a shooting star.

a reply to: imitator
We get sunshine! For a few days in the summer hah. Ah Texas .. sunshine and guns what more could you want? I'm gonna have to visit at some point lol

Since reading Eriks threads I've had to take a little time looking up a few things, I thought I knew a bit but I've gone back to researching the basics of photography. Keep up the work and I'll look forward to your pictures

What a wonderfully informative and enjoyable topic.

originally posted by: NGC224
Current setup

How much of the configuration is computerized? Are those counter weights on the bottom of the monopod?

Makes me wish I took some astronomy classes back in my college days. =)

What would be the total cost of a configuration like that?

I apologize, but when I saw Tripods in the thread title, all I could think of were the Tripods from "War of the Worlds". I thought: "Those must be some pretty powerful telescopes to see the surface of Mars."

I love posts like this. So much to learn from others experience. I'm faaaar from being a photographer myself, so lets say I'm enjoying taking photo with my camera
I was not prepared for the following shots I took but, it was no time to read.
If I'm lucky again I know what to do.

a reply to: eriktheawful

First up is: weather. If it's cloudy, even partly cloudy out, you are going to have some issues.

Second up is: Moon. Is the Moon out tonight?

Just adding a couple more...

Proximity to city lights.

How steady the atmosphere is.

On a warm day after the sun sets the earth is still shedding the suns heat, giving objects that twinkle from mirage. That makes pre dawn skies the steadiest for viewing or photography.

originally posted by: RightInThere
What a wonderfully informative and enjoyable topic.

originally posted by: NGC224
Current setup

How much of the configuration is computerized? Are those counter weights on the bottom of the monopod?

Makes me wish I took some astronomy classes back in my college days. =)

What would be the total cost of a configuration like that?

Cha ching... you don't want to know. The counterweights provide stability while exposures are being made during tracking.

a reply to: eriktheawful
Hello again Erik I'm just wondering if you can clarify something for me. On page one, the photo of the home made motorised mount the diagram says you need to do one revolution per minute. That must be pretty difficult to keep the timing or is it a case of every minute that passes you have to turn it

a reply to: eriktheawful

If you live in the northern hemisphere here on the Earth, objects in the sky when facing North will appear to move slower than objects in the sky when facing South.

What is the cause of that?

a reply to: IntruderAlert
I'm not sure if it's the same as when you go round corners because the earth is curved like a corner, the inside line of a corner is going to be quicker than the outside. So if you are in the northern hemisphere the objects closer to north (inside of a curve) move faster than the objects to the south (outside of a curve) that's what I thought when Erik posted that

That's just guess work though you may want to wait for the pro to turn up

a reply to: RightInThere

Yah, those are counter weights on that rig. That set up is heavy as hell.

Heavy price tag too. That's easily getting close to about 8 thousand dollars or more.

a reply to: ThePeaceMaker

With the Barndoor tracker, your suppose to turn it with the second hand on a watch, so it's constant.

Best thing to do is to practice doing it (and it does take some practice, heheh).

a reply to: IntruderAlert

The Earth's spin.

Earth's rotational axis is pointed towards Polaris in the northern hemisphere, which is why it moves very little during time laps photography, or star trail shots, like this:



You can see it in my shot I did last night:



If you take your camera, set it on it's back while shooting video, and spin it, you can see that objects directly up appear to move much slower, that the objects going to the edge of the frame of the video.

Once you cross the equator the view changes, where as things going south will appear to move slower (and if you could suspend your camera and spin it while pointing "down" you'd see the same effect. In fact, if you have two cameras that you can put back to back, and suspend them while spinning them and recording video, you'd see the same thing).

a reply to: ThePeaceMaker

The rotation should not matter in this case, since the two opposite sides of the viewable sky, north and south, are equally divided on both sides of the line of the direction the earth is spinning in from any given position on Earth.

The curve you are talking about does not have the right spatial orientation to cause the effect, since this is "sideways" and doesn't change the way the sky is divided equally into north and south from any fixed point on Earth.

a reply to: iasenko

Those shots are BEAUTIFUL!

Good job!

a reply to: eriktheawful

That doesn't explain this,

If you live in the northern hemisphere here on the Earth, objects in the sky when facing North will appear to move slower than objects in the sky when facing South.

a reply to: IntruderAlert fair enough even more reason to never pay attention to what I say haha I was just trying to guess .. my bad

a reply to: IntruderAlert

yes it does, because of the curve of the Earth.

If you live in New York, you will see more of the northern sky, and see the spin point of the north part of the axis, but you will not be able to see the southern spin point because you are above the equator.

If you live in the sourthern part of South America, you will see the southern spin point, but not the northern spin point for the exact same reason.

If, however, you live on or very near the equator and have a very wide angle lens, you'll be in for a treat:



You can see both spin axis.

a reply to: eriktheawful

You are still not explaining this statement, is this maybe a semantics issue?

If you live in the northern hemisphere here on the Earth, objects in the sky when facing North will appear to move slower than objects in the sky when facing South.

You are saying that if I look north in the NH, stars will appear to move slower than the ones I will see when I turn around to face south.

How can rotation cause this?