Clarkey

Duplicate post

4 hours ago, Astro Waves said:

I think there's a total of 2:20 of integration time maybe. I might keep going on it as well. Let me know what you think.

I think that is a pretty good effort - well done. A little more integration time will always help, but for 2.5 hours that is pretty good. Nice star colours too.

What scope are you using?

14 hours ago, vlaiv said:

You should bin at linear stage, either after calibration and before stacking or stack once it is finished.

Tried again binning the stacked channels. I the black point is slightly different but is there a significant noise reduction? It is processed slightly differently so maybe difficult to tell.

I have just had a look at my 'Hamburger' and found one of the quasars at 10.5 Gly away. That's 3/4 of the age of the universe! I then thought about it a bit more and my brain melted🤣

It's funny how many people seem to have endless problems with USB. I have a 15m USB 3 active cable and a 12v powered USB hub and have had no issues over the last year of use. I have taped all of the joints and 'active' parts of the cable to make it as waterproof as possible. I seem to be the exception though!

Thanks Vlaiv.

The 0.73 was an estimate based on the TS look up table and the spacing. It may well be slightly lower. At this reduction it is not too bad. There is a small amount of vignetting (which is uneven due to the collimation) but this calibrates out. When I collimate it will give me a better idea of the reducer performance. I know the collimation is out as even with a Cheshire as I can see the secondary is a long way off. Optically it might not be too far out, but mechanically it is. This might be linked to focuser tilt but until I start to adjust it, I won't know.

I think the reducer is certainly worth using. Imaging at 1200mm really helped with the exposure times needed. Even binning 2x2 this gives a good pixel scale and if I happen to get an exceptional night of seeing (it does happen very occasionally) using 1x1 would be about right.

Interesting about the pixels though. I am pretty sure the image was cropped harder than 100 px but I don't have the original files on this computer. I wonder if AP re-sizes the cropped image to the original scale? Something I will look into.

28 minutes ago, vlaiv said:

Your stars look rather decent.

Here is crop form "worst" corner at good sampling rate (x0.5 or about 1.32"/px) :

I use APP for stacking and initial combining of LRGB. I'll try binning the linear image before processing and see what difference it makes. Before, I tried it in the camera and after the initial stretch but I saw minimal benefit.

28 minutes ago, vlaiv said:

Your stars look rather decent.

Here is crop form "worst" corner at good sampling rate (x0.5 or about 1.32"/px) :

The image has already been cropped slightly as the edges were not good despite calibration frames and gradient removal. On the full size image the corner stars a out of shape. This seems to be exaggerated by the reducer.

16 minutes ago, tomato said:

Great depth, detail and colour, nice framing too. And with the moon up too!👍

Thanks tomato.

4 minutes ago, vlaiv said:

What did you use to reduce FL on RC?

By the way - you should look into incorporating at least bin x2 (or optimally x3 for this image) in your work flow - it will give you SNR boost and make processing much easier.

It was reduced using a TS CCD47 reduced to about 0.73. I know the stars are a little out of shape - my scope needs collimating. I'm just waiting for some kit to do it. I know in theory you can do it with a Cheshire and a stars for closer alignment - but I am being a bit of a coward!

I have tried binning but it did not seem to make much difference. I tried binning in the camera and binning in software (Affinity) but I saw no significant difference. I am not sure the best time to bin the data. Should I bin each channel before combining, after combining but before stretching, or towards the end of processing? Obviously being a CMOS there are not huge benefits like with CCD. However, my slow PC would certainly speed up!

You might be ok with number 1!!!!!!

55 minutes ago, MartinB said:

That's is really nice, plenty of detail in the core and beautifully smooth outer regions.  Have you thought about doing some Ha?  There are some lovely Ha "jets" in there

Thanks for your kind comments Martin. I'll have a go at the Ha next time I get a weather window. Maybe May😂 Thanks for the tip.

Yes. I set mine to run all night if the forecast is OK. I use a rain alarm app on my phone to warn if there is an rain in the area to give me a bit more peace of mind. So far I have not had any problems. The other option is sleep with the computer and when it starts pinging due to lost guide stars I can decide what to do. If I did not do this I would not really be able to image due to work / kids / exhaustion. I get up in the morning to see when the clouds came! I don't bother with lens caps or anything - if the rig has been out for 6 hours imaging, more won't hurt. NINA does allow you to park the scope and warm the camera which I sometime use.

Those look much better. I particularly like to first one. Well done. 👍

There is some interesting stuff in the link below regarding EQMOD and EQDIR - might be worth a read.

EQMOD - Controlling the HEQ5, NEQ6 and other mounts directly from a PC | First Light Optics

I use PHD2 but I do not use the ST4. I use a EQDIR cable like this one:

Lynx Astro FTDI EQDIR USB Adapter for Sky-Watcher Mounts (see description for models) | First Light Optics

This goes direct from the PC (or my case via a router) to the mount. I'm led to believe it is a better option and it allows you to control the mount from other software such as Stellarium. (You might be able to do this with ST4 - I have never used it). There are a number of discussions on this forum regarding EQDIR vs ST4, just do a search.

Definitely looks like the 9x50 as stated above. I use my 9x50 finder with a zwo120mm mini and it works fine. Unless you are planning to upgrade later the 120 is fine and a bit cheaper. Obviously the 224mc can be used for imaging too.

Am I allowed to offset this bit of stupidity by saying that so far I have:

a) not left my lens cap on

b) not left my bahtinov mask on

However, there is a first time for everything. (I have done 6 hours of blue data instead of luminance, but I don't think it counts).🤣

Oh yes. D'oh! There was me trying to work out what I could image in one night or multiple nights without touching anything......

I'll quietly go to a dark corner and hang my head in shame. 🤪

At least I have a RC so rotating the tube is not a problem!!

Exceptional image. Worth the wait. 👍 Another great image from the Samyang 135mm.

This is probably a bit of a daft question, but with scopes with secondary mirror holders how do you keep them aligned if imaging on multiple nights? With my other scope (ED80) this is not a problem. As long as the image is close to being aligned, once stacked and cropped it becomes a clear image. With the RC, unless I do not move the camera at all between imaging sessions, it is virtually impossible to align the diffraction spikes. Using a X on the screen can get pretty close, but if having to frame a subject at an odd angle this will not work either. I know a camera rotator would work but this is a bit out of my budget for now.

Has anyone got a neat way round this problem?

I probably had issues the first couple of sessions but then it was OK. I have had problems when I have created new profiles and forgot to change or add stuff. To get it up and running you literally have to go through each setting page by page or it is easy to miss something. Also, the error messages in NINA are not always terribly helpful so working out the fault is not always straightforward.

I have never had NINA hanging - this may be a comms issue?

I there are any specific problems, I'll do my best to help. I think if you do get it working it is worthwhile.

I think ultimately it is all down to personal choice. I use NINA now, but have used APT and BYEOS in the past. All have their good and bad points - none of them are perfect. I think if you have found something that works for you then stick with it. I only moved to NINA for the autofocus routine that can be done during an imaging session. As I try to set up and go to bed this is quite important. However, there are faults with NINA, although for me at least more annoying than major.

Just checking as it would cause the graph to move slowly. You can change it on the left of the graph where there are options for the two axis.

Have you increased the x axis value from the default 200 to 400?

I started with nothing last January. I got a 200p for visual with an HEQ5 which I used for a couple of nights before the AP bug got me. Now I have a collection of scopes and mounts plus my own kid-free astro cupboard for everything else. (My profile below needs updating with a new Alt-Az and another guide scope).

Oh yeah. I'm now skint 🤣🤣

Generally with reducers you can go slightly closer than the stated distance and it will still be OK. I think you may find the Astro Essentials reducer has a fairly small image size so you will get some vignetting. I changed to the TS Optics CCD47 which gives up to 0.67 reduction, but I have it slightly closer so it gives 0.73 reduction and a larger imaging circle.

In terms of where it goes in the imaging train, I have mine inserted into the draw tube so I can change from reduced to native FL without removing the focuser (giving the 254mm distance). From what I remember the same set up worked with the AE 0.75. The image shows the reducer and whole lot is pushed into the draw tube up to the filter wheel. The stars should be flat across the field without a reducer, if they aren't it is either tilt or a collimation problem.