Chefgage

I imaged the North American nebula in Ha using my hydrogen alpha clip in filter. The images have been stacked and I use GIMP to process them. The question is how to extract the red channel to then just process this. I have used the decompose to RGB with the decompose to layers option ticked. This then gives me a grey scale image to then process. Is this the correct way to extract the hydrogen alpha data to process?

When I am using just my DSLR and lens on the star adventurer I use a red dot finder and hot shoe adapter. This is the one I use https://www.365astronomy.com/Blitz-Hotshoe-dSLR-Camera-Adapter-and-Red-Dot-Finder-COMBO.html I then take a short sub to properly frame up the target.

Imaging with just a camera and lens is indeed astrophotography. It depends on what you are trying to image. For example the North American nebula fits nicely in a 135mm lens but will not fit very well in say a DSLR connected to a skywatcher 72ed refractor of focal length of 420mm

1

I power my asiair pro from this https://www.rothervalleyoptics.co.uk/celestron-powertank-lithium-lt-61ah.html

I am using 5 plus and it doesn't have this feature. Mind you it might have, I am out imaging at the moment and my brain is getting cold.

Again thanks, I understand it now after reading your first reply. Using the software I use I can see the transit times, so this now helps.

Right I get it now, thanks.

That's the one. Thanks. That gives me the the information I was after. For the Orion nebula it will at its highest altitude from my location at 10pm on the 14th January.

Not quite sure what you are saying. The max altitude will not be the same regardless of the date surely? For example the max altitude of the Orion nebula in my location is 31 degrees at about 1am tomorrow morning. But in a month's time at 1am it will be 27 degrees. Possibly my explanation in the first post was not clear. It's at what time and date of the year a object will be at its highest altitude relative to my location. I can see on sky safari for each date and time I choose. But not just that one time and date it is at its highest.

Hello all. Having not used Stellarium very much (hardly at all really) as I use Sky safari for most things. Is there a way to show the maximum altitude an object will be during the year from my location using Stellarium? Using sky safari I can centre on an object and then fast forward through time to see how high the altitude gets but this is quite time consuming in that you are just changing the dates for a given fixed time or changing the time for a fixed date. A way to just input my location and choose a target/object and the software will show the maximum altitude it reaches would be very helpful. An example using sky safari is centre on the Orion nebula. Set the time to say 8pm then keep changing the date by days ahead to see the change in altitude. The problem with this is that it is fixed on 8pm which for that given day will not be the maximum altitude.

You fix the dovetail to the mount exactly like you have done. It's just the design of this type of connection. There are different types out there as mentioned but the marks/indents do not hamper it's performance.

Have you thought about a clip in filter for your DSLR? I use this type https://www.harrisontelescopes.co.uk/acatalog/skytech-cls-canon-eos-clip-filter.html?gclid=Cj0KCQiAhs79BRD0ARIsAC6XpaWe5phCbxkfNit8tXskT4sv-PZJvdktHdJMhrfrDD0prSoQufeEAkIaAun8EALw_wcB

After a bit of research in to this that is the conclusion i came to that the adapter/usb types do not deliver the correct power.Thats when i saw this dedicatedbattery with the correct output voltage for my dslr. Seems to work so far.

Here you go. The battery came with the DSLR dummy battery. My camera is a Canon 200D so requires the DR-E18 DC coupler (dummy battery).

I power my DSLR with this. Lasts all night.

I seem to be buying an item of astro photography gear every week now. I get a bit fitted then think mmm I need that bit on the mount now!

I needed an extension for my Canon 200d DSLR. Without it I could not get focus. The general recommendation for this scope is a flattener of course. I used an OVL field flattener which gives me the correct distance to gain focus. So it it does 2 things at once, gives me focus and flattens the image.

Enjoy the 72ed, I certainly like mine.

An Expro battery with dummy battery to power my Canon 200D DSLR. I find with the standard inserted battery I only get about 3 hours worth of power. With this I can image all night.

Regardless of where the clock numbers are pointing, Polaris needs to be in the correct position. Take this example. The clock face has been rotated anti clockwise but Polaris is still in the same place as in the first image and second image.

Yep it was a typo, I need to learn how to tell the time! No you do not align Polaris relative to 0. The explanation above by masjstovel explains it better.

Thinking about this the reason I used the OVL field flattener is because 1 it gives me the correct spacing to get focus on my canon and also to flatten the image. This spaced distance is correct for my canon camera but might not be correct for your camera. You will still probably want a flattener though. So not really sure with your camera. You do have the added advantage though of being able to pull the camera out slightly to give you a bit more distance (I assume you have already tried that though).

To start with I put the clock face correct so 6 at the bottom. This is only so it helps when showing where Polaris is relative to the position on the app. When you move the scope/camera to your target this clock face will obviously move. But Polaris will still be physically in the same position. So if the app shows Polaris say at the 9 o'clock position then that's where it needs to be, i.e. to the middle right. Regardless of where the clock face is rotated to. This is because as you move the scope around this turns the clock face. When polar aligning you are aligning the mount not where the scope is pointed. Which app are you using? I use the star adventurer mini console app

If you are using the app to show you where Polaris is then you do not need to bother with the date graduation circle. Using an app to show you where Polaris is on the polar scope is the easiest way to it. Using the date graduation circle/setting is only used if you cannot use an app to show you where Polaris should be.