[Gimbal]

I made a couple of observations last night. The first one is perhaps common knowledge but it was new to me, one can use the 2 sec mirror lockup (or the normal mirror lockup) when using astrotracker. I didn't expect that since the mode dial is in bulb, but it works.

The other observation is a bit more strange. First I was shooting pretty much due south, 135mm 30seconds without trails. No problems. Then I changed direction to west and higher up and it was impossible to get rid of the trails. After a number of calibrations (each calibration done in a different way) but with pretty much the same results I instead turned the camera to portrait orientation, and the trails where gone. I even shoot 60 sec (and 135mm) without trails. This might be something to look into, or perhaps it was a one time only thing?

[d00d]

First I was shooting pretty much due south, 135mm 30seconds without trails. No problems. Then I changed direction to west and higher up and it was impossible to get rid of the trails. After a number of calibrations (each calibration done in a different way) but with pretty much the same results I instead turned the camera to portrait orientation, and the trails where gone. I even shoot 60 sec (and 135mm) without trails. This might be something to look into, or perhaps it was a one time only thing?

Hmmm my shot above was shot due south at a pretty high declination and I was under the impression that shooting above a certain degree in declination one was out of luck, though what that exact figure was or would/will be was largely dependent on global location. When I have some clear skies I'll try this to see how it works for me at my latitude.

[oneeyedhawk]

I have a K5 and and astortracer unit. Using the DA 55-300 lens at 300mm and finished the calibration routine the camera astrotracer menu tells me the maximum exposure depending where I point the camera. When I point to the north I will get a 5 minute max as I move the camera around the sky the exposure time changes to as little as 1 minute when pointed southeast. When I change the FL to 50 mm the exposure time stays 5 minutes no matter where I point the camera. I also get the best results (round stars) with the exposures taken soon after the calibration routine.
Hank

waiting for clear skies and less snow, here is a fast shot of orion, one exposure, as you can see the stars are elongated in this 40 second shot but not bad, with some work and a firmed up tripod (not on wooden deck) pictures should improve, the potential is surely there.

[mtansley]

I also have a K5 and am trying out the GPS unit.

Not being an astrophotographer I would like to ask HOW do you line up the camera to see what you want to see through the viewfinder.

I had a lot of difficulty getting things lined up. Living in a light polluted town doesn't help either. This is the best I could come up with.

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[oneeyedhawk]

That is always a time consuming pain in the back side. You could use one of these--
“Tactical” Red Dot Sight for Camera | The Firearm Blog
A red dot finder that mounts on the camera hot shoe.
After getting the camera pointing in the right direction, focus on a bright star using live view and high mag.
Since all stars are at infinity I put a white dot on the focus ring when I first obtain good focus.
I then use this dot as the starting point for all astro photos. Then fine focus if needed.
You could also mount a small 60-80 mm scope on a tripod and mount the camera on top of the scope with a set of finder scope
rings. Align the scope with the camera and shoot away.
Or buy a t-adapter for the camera and shoot though the scope.

good luck
Hank

[Stone G.]

I also have a K5 and am trying out the GPS unit.

Not being an astrophotographer I would like to ask HOW do you line up the camera to see what you want to see through the viewfinder.

I had a lot of difficulty getting things lined up. Living in a light polluted town doesn't help either. This is the best I could come up with.

I live under a severely light polluted city sky too and know your problem very well. My solution was to make a small finder scope from bits and pieces:



Even though it is small, it is much, much brighter than what you see in the camera viewfinder.

[mtansley]

I live under a severely light polluted city sky too and know your problem very well. My solution was to make a small finder scope from bits and pieces:
Even though it is small, it is much, much brighter than what you see in the camera viewfinder.

That is impressive.

Is that finder scope basically a couple of small lenses in a homemade tube?

How do you align it? Use something in daylight very far away and match the camera to the scope?

Would a simple air rifle scope work?

Thanks for the info, I'll have to attempt something like that.

[mtansley]

That is always a time consuming pain in the back side.
good luck
Hank

Thanks. I'm glad to know it's not just me that finds it a hassle.

I guess ultimately one could 'cheat' and use one of those 'go to' positioning systems but then you don't need the GPS unit on the camera since I suppose those units already follow stars and have an equatorial mount.

[d00d]

Or just piggyback it on any decent reflector...

[mtansley]

Or just piggyback it on any decent reflector...

Nice idea but I don't own a telescope. I'm just trying out the GPS unit on the camera.

That's why I'm trying to find a 'low cost' way of targeting the camera.

However, what sort of simple mounts are there that let you connect the camera on top of the telescope body?

[d00d]

Nice idea but I don't own a telescope. I'm just trying out the GPS unit on the camera.

That's why I'm trying to find a 'low cost' way of targeting the camera.

However, what sort of simple mounts are there that let you connect the camera on top of the telescope body?

I've been pretty lucky, the targets I've attempted to shoot are easy enough to bring into view (even with a 500mm).

Actually any inexpensive scope would do the trick I suppose, check swap meets/yard sales even.

As for simple mounts, I thought I saw a generic mount but all I can find are ones that are for through the eyepiece shots or scope specific mounts for piggybacking.

That said one could adapt a tube ring with a 1/4-20 screw but simpler and cheaper than that, I'd use some plumber's tape (even better a hose clamp) with a 1/4-20 bolt through the strap. Attach the camera first to the strap, then wrap the plumber's tape around the scope and bolt the ends to snug it up on the scope tube.

[mtansley]

I've been pretty lucky, the targets I've attempted to shoot are easy enough to bring into view (even with a 500mm).

Actually any inexpensive scope would do the trick I suppose, check swap meets/yard sales even.

As for simple mounts, I thought I saw a generic mount but all I can find are ones that are for through the eyepiece shots or scope specific mounts for piggybacking.

That said one could adapt a tube ring with a 1/4-20 screw but simpler and cheaper than that, I'd use some plumber's tape (even better a hose clamp) with a 1/4-20 bolt through the strap. Attach the camera first to the strap, then wrap the plumber's tape around the scope and bolt the ends to snug it up on the scope tube.

Ok, now I understand, a cheap telescope to mount the camera on and just use the cheap telescope as the finder. Once the camera is adjusted for X & Y (hmmm, azimuth & elevation?) on the telescope you're good to go. The optics of the telescope aren't too important in this case. Presumably you could align the camera & telescope during the daylight using some target a reasonable distance away.

Actually, if you don't want to do really deep sky stuff, surely just using an empty tube and sighting through that would work for rough & ready. ABS pipe for instance.

Talking to you folks is beginning to give me some simple ideas.

[Stone G.]

That is impressive.

1) Is that finder scope basically a couple of small lenses in a homemade tube?

2)How do you align it? Use something in daylight very far away and match the camera to the scope?

3) Would a simple air rifle scope work?

Thanks for the info, I'll have to attempt something like that.

Thanks mtansley,

1) Yes - an eyepiece from a polar scope, a little lens and a Havana Cigar tube!

2) Living in the city it is fairly easy to find a remote building/lamppost that can be seen both in the finder and in the scope. But a bright star (such as Vega) can usually also easily be seen in the camera viewfinder (not to speak of the Moon).

3) It definitely should work - or how about a cheap (toy) monocular. There are many means.....

[mtansley]

Thanks everyone for the assistance on putting together a finder scope.

I feel a complete idiot right now.

I was in my 'toyroom' looking around and I suddenly realized I had one of those 'Gallieoscopes', a cheap plastic kit telescope that came out a couple of years ago.

I think I can mount that next to or on top of the camera, and sight with that. It's got to be better than trying to sight through the viewfinder of the camera.

It took a while but this old mind now can see the way forward. Now I'll probably have cloudy skies for the next month or so!!

[d00d]

Thanks everyone for the assistance on putting together a finder scope.

I feel a complete idiot right now.

I was in my 'toyroom' looking around and I suddenly realized I had one of those 'Gallieoscopes', a cheap plastic kit telescope that came out a couple of years ago.

I think I can mount that next to or on top of the camera, and sight with that. It's got to be better than trying to sight through the viewfinder of the camera.

It took a while but this old mind now can see the way forward. Now I'll probably have cloudy skies for the next month or so!!

Brillilant! If you have a disused flash, remove the hotshoe and epoxy it to the scope!