scitmon

Certainly looks like incorrect spacing between your flattener and the camera (should be 55mm), can you describe what you have in between these?

They should both be the same. 

The things to check are:

• your position (lat and long) check its right with another source (i use the iphone compass app) 
• date/time are correct... make sure you check that daylight savings time is on and the date format is correct (its easy to mix up month and day). 

Perhaps try another app to see which one out of your hand controller and Stargate PA is correct.

There are lots of helpful tutorials on you tube, I would recommend to seek some out.  This  for example.

EDIT: sorry I just realised you have been following a guide.  Without knowing what you did it's hard to say, perhaps post your stacked image for others to look at.  Have you tried stretching the image more by bringing the mid tones to the left.  You could probably clip  more from the left of the histogram too without clipping much signal.

A quick google also shows that you can disable this effect:

Method: Disable automatic enhancement.

1.    Open Photo app.

2.    Click on Settings.

3.    Under the Viewing and editing tab.

4.    Turn off Automatically enhance my photos when they can be improved.

I suspect it's not GIMP adjusting the brightness on export, but the Windows viewer application doing some runtime adjustments.  I've noticed it doing this if you are scrolling through a batch of images, it opens then quickly applies some kind of white balance adjustment.  Try opening the exported file in something else and see what it looks like.

I've had a very quick process with Pixinsight, I just did a crop, background neutralisation, colour calibration, histrogram and curves transformation:

I think I see slight elongation of stars which indicates your polar aligment is possibly slighly out, which would effect fine details.  Having said that, you have a very respectable attempt there, especially with the moon up.  I've always found it tricky to get any colour from M31, I think the trick is to get more data, preferably without LP from the moon.

Hope you are satisfied with the camera so far, you'll find it come into it's own with HA rich nebulas, not really much in M31.

22 minutes ago, Budgie1 said:

With 294MC, as said above, the spacers came with the camera.

You need the 11mm screwed onto the front of the camera, then the 21mm and finally the 16.5mm. Screw this assembly directly onto the back of you flattener/reducer and you should be good to go.

If you want to do the maths: 11+21+16.5=48.5mm then add the 6.5mm from the front of the camera sensor to the front face of the camera casing to give you a total of 55mm. You also get another adaptor which screws into the 11mm spacer which will allow you to mount a 1.25" filter in there. It's an idea to use a UV/IR cut filter in here becasue the 294MC doesn't have a UV/IR cut filter built in and the stars can look a little bloated without one. 

As for testing the camera, connect it up to the scope and get out there! Failing that, you could start building your dark frame library. Just put the cover over the sensor (the camera doesn't need to be connected to the scope for this), connecting it to a laptop/ASIAir and cool to your required temp, I used -10° last season but I'm going to try -15°C for this coming season. Then set your gain (I stick with a gain of 120) and take about 20 frames for each exposure setting you're likely to use. 

The beauty of these types of camera over the DSLR is that you can build your darks library before you start and then just reuse the masters, unless you decide to change the gain or offset settings you're using.

Thanks thats sounds reassuring… on the other side of my ff/fr i’m using a t nose instead of screwing it directly onto the draw tube, will this introduce unwanted spacing or it it only measured from the ff/fr glass?  I screw my idas lp filter on the end of the nose too which should cut out the need for an additional IR filter?

I can't imagine focus changing enough to warrant separate flats.  I would be happy to be proved wrong though.

I'm taking delivery of my ZWO ASI294MC today and I have questions:

1. Back focus... what is it?  I'm guessing its the required distance needed from the back of the telescope to achieve focus with the camera?  ZWO say most telescopes require 55mm, but is that a rough guide or does it have to be exact?  Will my FF/FR on my 80ED eat into that back focus?
2. Can people recommend what I should do the test the camera is working correctly?
3. How do I determine what length on sub I should use for flat frames?  I previously just used AV mode on my DSLR.

On 17/06/2021 at 12:23, Sterrenland said:

Well, I pushed he button and got myself the 294MC-Pro!

Having spent the last 2 years using a DSLR and creating my workflow, I think there will be an initial learning curve using the new camera and the ASIAIR PRO and the app on my tablet...hopefully it'll be worth it. Fingers crossed! I've not had a chance to try the camera yet...as soon as it arrived the clouds came over!

And thanks for your help/advice above.

 

I'm about to hit buy on the 294 myself for my 80ED.  Are you happy with your purchase?  Also may I ask which spacers you are using, and do they come supplied with the camera?

With pixinsight you can create an Image Container and put all your images in that, then apply processes (or process containers) to them all.  https://pixinsight.com.ar/en/docs/33/pixinsight-image-container.html

3 hours ago, Newforestgimp said:

Promising, Could I enquire what spec you’re running ? There are thousands and I’m struggling to know what is more than enough to do the job. My guess is win10 is the biggest drain on resource. I’m looking at 2nd hand rather than new.

I purchased mine a while ago and times have moved on since then... but it's a N34 Intel Mini PC (2.2Ghz CPU, 4GB RAM, 64GB SSD).  Then I bought https://www.amazon.co.uk/gp/product/B008DCORUG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 to power it from my DC Power Supply.

Yes I am and I am also running it on 12v.  It works really well for the most part.  My only issues have been Wifi reception sometimes.  Go for one with fast solid state memory, and keep on top of your Windows updates!  There is nothing worse than setting up for a night of imaging and having Windows updates ruining your night.

The Flats should have taken care of the vignetting.  Did you use Av mode on your camera to take them?

A green cast is common on DSLR's due to the bayer pattern having 2 green pixels for every 4 on the chip.  They should process out easily and are nothing to worry about.  

Canon DSLR is a good starter camera then.  As for which one, depends on your budget but they all will do a good job.  I've seen a few in the classifieds recently, you may want to look there.  I would also recommend looking at https://www.cheapastrophotography.com/Available-Cameras.html and see what your budget can get you.  The next step up would be a cooled camera which starts at around £800, so if you start getting close to that I would look at those instead.

What objects are you looking to photograph?  Photographing large nebula is very different to imaging planets for example.

If you are looking to do long exposure DSO's such as emission nebula then Canon DSLR's are a very good beginner option.  You may even want to consider buying a modded one if you are solely using it for astrophotography.   

@wimvb may I ask why you Resampled the image? I wondering what the benefits are beyond the obvious memory saving.

Some lovely detail there.  I have been umming and arrring over the optolong dual band filters for my 700d so i'll be watching this thread with interest.

10 minutes ago, tooth_dr said:

Thanks for the link. I am for sending my current SharpStar back, don’t think I’ll buy another. 

Oh? What was wrong with it?

https://www.firstlightoptics.com/askar-telescopes/askar-fra600-f56-108mm-quintuplet-apo-astrograph.html

might be worth looking at?

All the work is complete.  I insulated the walls with PIR insulation boards, leaving a 25mm air gap to prevent moisture being held against the cladding.  I did not ventilate the air gap like you would with a brick building because there wasn't any easy way to do so.  I don't believe its entirely necessary as the cladding would absorb any moisture in the gap and dry out from the outside.

As for the ceiling, I again used PIR insulation board, but left no air gap because the warmer air condensing in the gap against a colder ceiling is not a good idea.  

Also, and most importantly, I made some ventilation holes in each corner of the shed.  

I've had it like this for a few months now and the results are impressive so far.  The temperature is noticeably warmer than the outside so far, and I'm hoping it stays cooler when warmer weather comes.

I assume you are talking about cement, concrete = cement + aggregates like sand and stone.

You would probably be ok normal multipurpose cement, but I would be inclined to go for sulphate resistant cement for anything that is below ground level.  I would also use a damp proof membrane between the concrete and earth to prevent it absorbing ground water.

Absolutely gutted, I was going to order my SW pillar mount with my Christmas Vouchers this week, and its gone up 60 pound

3 hours ago, Jm1973 said:

Great. That sounds like it will do the trick.

/puts hacksaw away

Before you do go and buy one, I would double check you can't get focus with a star or the moon.  I don't know how much your moonlite focuser has effected the spacing, but I find it strange that just adding this rotator would throw it off so much.