CKP

Thanks for the replies guys. I was just trying to wrap my head around it, but I guess that's why its called an illusion!

When manually observing,  the target goes out of view quicker when using higher eyepieces.

When tracking would I need to change the speed to compensate for this?

Thanks.

8 hours ago, Penumbrella said:

I had first light with the mount last night, so can report (well, report again, I know others also use this combo) that the mount is just grand with the 130pds, wearing a telrad and a range of eyepieces (including a 2inch 30mm which probably took the whole show to close to the 5kg limit). Vibrations settled quickly and it felt fine - though my only really frame of reference here is my eq3-2 mount. I'm using an INNOREL NT364C tripod and the adm upgraded saddle both of which probably helped. 

I'd done the homework in the day of updating firmware and connecting to skysafari etc. So I found the alignment process pretty straightforward and the goto accurate enough for everything to be in the eyepiece (even though I rushed through this in my excitement). I saw sooo much more in that session than I have before. Superb. 

However, not all was well as the mount made some unwelcome noises throughout. Constantly, starting a couple of seconds after the goto settled - during tracking, there was a constant, loud (like, worrying about the neighbours loud), 'tock-ing'. It sounded like the mount was struggling and when viewing jupiter there were noticeable wobbles in time with the 'tocks'. I'd tried a friend's az-gti last week so I was not expecting any of this. The mount made the same noises when left to track without the scope attached too - I had wondered if it was a load issue, but alas no. It did seem to be related to the clutches - in that slackening them off would modulate (but not stop) it. 

I made a recording in case wiser heads have other opinions (?), but having read through previous posts I think I see other reports of the same problem and my options are to open it up for some tweaks or to return it for a replacement - I think I'll be doing the latter. 

A disappointing end to an otherwise excellent start. 

Thanks for the update @Penumbrella

It seems you got on great with your first light, especially seeing more than you have ever seen before! It sounds like you were fully loaded too!

Sorry to hear about the clutches on your mount, was they tightened up too much? At first it sounded like a load issue, but if it happened with no scope on it, I guess not.

If its new I'd send it back, opening it up would void your warranty.

Hopefully you'll get it sorted easily enough.

4 hours ago, Penumbrella said:

Exciting day as I've just received an early birthday present from myself (I always get such thoughtful presents from me!). 

I'll be using it for visual in alt-az for now (I don't have a wedge or immediate plans for long exposure photography - might try EEA down the road though) and tried my 130pds on a friend's az-gti before pulling the trigger. 

Currently trawling through the mine of knowledge on this thread and waiting for the, inevitable, clouds to clear for first light. 

Nice present! I bought myself the az gti for my birthday too!

How does the ota feel on the mount, I'm thinking of doing the same. I use the heritage 130p at the moment but don't like having to make light shrouds and the crappy focuser! 

I forgot about this thread and should of posted this here. My apologies.

Hi,

If I do the eq mod on the SkyWatcher az gti, would I need to use tube rings? I've heard you need to be either a contortionist or move the OTA  in its rings? I've no experience with eq mounts so I have no idea. Currently I'm using the fixed vixen bar on my heritage 130p without the eq mod.

Thanks.

Hi,

If I do the eq mod on the SkyWatcher az gti, would I need to use tube rings? I've heard you need to be either a contortionist or move the OTA  in its rings? I've no experience with eq mounts so I have no idea. Currently I'm using the fixed vixen bar on my heritage 130p without the eq mod.

Thanks.

14 hours ago, StevieDvd said:

I'd suggest checking whether your moun thinks it is on daylight saving or not for one. And resolve the level using a good spirit level to see which is nearer to true (mount or trpod) and that the base of the mount has a good connection with the tripod.

 

 

 

How do I check if the mount is on daylight saving? I use the app on my phone (galaxy s9) and my phone is on automatic time settings. When I put it in manual mode it is gmt + 01:00 british summer time.

The connection between the mount and tripod is solid, I will try using a real spirit level on the tripod to compare it with the built in bubble.

7 hours ago, Psionmark said:

I've been down that route It took approximately 1 entire observing season (so basically a year) for me to get to the point where I can be outside grabbing EAA images with my setup within about 10 minutes of thinking about it. It took a LOT of trial and error, new kit, repurposing of old kit, trying to understand what I'm doing lol. I've still a long way to go, but at least I'm now at the point where I spend more time observing and less time head-scratching.

Keep at it - it's well worth it  I also have the AZ-GTI and plate-solving works a treat but, as others have said, start with the basics and build up.

Thanks for the support

3 hours ago, Elp said:

I think on synscan pro in the top right corner of the app there is an "i" icon and if its tracking they'll be an ">>>" next to it, otherwise I think it's in one of the menus where you can set the sidereal type (sidereal, lunar etc) and set the speed which I normally leave on 0.9x. In essence it is only controlling the motor speed to counteract the rotation of earth, an autoguided setup does the same whilst looking at reference guide stars but with better accuracy hence why it's essential for long exposure astrophotography.

I'll have a look next time I'm connected. 

Is there a way to improve the traffic accuracy? I guess the only way to do a more accurate polar alignment would be to do the eq mod?

21 minutes ago, Elp said:

If you're using autoguiding to track the stars to keep your target centralised you can specify and set dithering settings, instructions for the mount to move off target a set number of pixels after a set number of images have been taken and it keeps repeating in random directions yet keeping the target fairly centred (eg if set at 5 intervals it will do a dither after every 5 images captured). By doing this it helps to eliminate walking noise where camera hot pixels might be in the same place every time, if stacked without dithering they will appear as banding or lines on the stacked 

Is autoguiding when you piggy back another camera and smaller scope on top of your original scope?

I don't do this, I just line up the target on the live view screen and then hit live stack.

When using the synscan app, when I've typed in the target and found/centralised the target does it automatically track the target?

8 hours ago, Elp said:

Likely, or the stars are streaking so it can't resolve them. Minor drift shouldn't be an issue as long as the target is generally centralised as dithering if used moves the scope around at set intervals to accommodate for walking noise and image sessions with dithering stack fine. I have experienced in the past if the target has moved too much it won't stack correctly, I assume it's because the registration stars the software was using had lost the view of some of them.

I do centre the target before starting the live stack. What is dithering? Do you pause the stack and recentre the target?

2 minutes ago, cajen2 said:

The 130p is good enough to show excellent views even with good-quality, relatively expensive eyepieces. A range of 4-10mm EPs would be great for doubles if you can afford them (Pentax XWs, Baader Morpheus, etc).

I do have a range of bst eyepieces and a x2 Barlow. Hopefully these will be enough, took a while to get this set, I don't really wanna start a new set 😬 

Ah, I'll stick to my reflector until I'm ready to go bigger then.

Hi,

They say aperture is king, it seems quite obvious when looking for fainter objects.

They also say focal length is better for double star observing.

I have the heritage 130p reflector but was wondering whether or not a skymax 102 would be better for double star observing based on the above calculations?

I look forward to hearing peoples thoughts on this.

Thanks.

I was taking 30 second exposures last night with the az gti and the heritage 130p ota. The tracking was great with no trailing, but at 9 minutes worth of stacking sharpcap stopped stacking saying it couldn't align?

Does this mean the tracking has started to drift off course? 

Thanks.

I had another go last night, practice makes perfect and all that.

I went for 30 second exposures, but after 9 minutes it started ignoring frames saying last xx frames couldn't align. Is this to do with tracking?

Also, I saved the raw files but when I loaded them onto sharpcap they were black and white, there was no histogram to play with?

I did also take an image of Albireo, just to see if it would show the split and the colours too.

There is alot more to it than just point at a target and hit the stack button!

So, the best option would be to start with a lower exposure and gain and run a few stacks. See how it looks and then try adjusting gain and exposure before playing with the histogram?

A quick look on google says that my camera doesnt have unity gain, so I guess it's going to be a question of trial and error.

I'll have to save the next attempt using every save option.

What is OSC?

Do you play with the different colours until you get the desired result?

I do have a fair bit of light pollution living in a built up town and having a lamppost close by.

EDIT : would you recommend extending the exposure from 20 seconds to 30 seconds and add more stacking as well as lowering the gain?

I've had a look for the fitts files and found the spec info. I have also added the photos for reference.

I think the less stacked image come out better, I guess I messed up badly on the second attempt!

Stack_16bits_13frames_208s.CameraSettings.txtStack_16bits_13frames_208s.fitsStack_33frames_440s.CameraSettings.txt

40 minutes ago, Martin Meredith said:

No, mine didn't have darks, but they won't resolve this issue in any case.

Did you save any FITS files from your last session? If not, that's the thing to do next, because then you can reload them or someone on the forum can take a look to see if its an image manipulation issue or if its a gain/exposure/other capture problem.

 

Is the fits file the written file that has these setting values inside? I think I still have the file, I'll have a look when I get back home.

How do I save the images on sharpcap?

When I press save it saves a single image?

I need to save the individual images so I can learn how to do it.

@Martin Meredith

Does your image have darks? i played around last and i seem to be going backwards. I have to do post processing to see details.

I think I did 33 stacks and tried to play with the mid level as well as the black level, but I couldn't bring out any detail?

Should a short exposure have a higher gain and a longer exposure have a lower gain? When I processed it, the brighter the image the more detail has come through. The image seems to get brighter on a higher gain, if I remember correctly.

I'm also going to start one target at a time I think.

The image of m57 I did a few nights ago was beginners luck I think!

@M40 or anyone using asilive...

When you open up the software and turn the camera on, after the first exposure does the image on the screen show stars on a dark background?

When I do it, the screen looks like white noise and I can barely see the stars behind it.

This does not seem right, I'm sure its the settings but I gave up on it simply because I also have sharpcap.

I watched a video with someone using it and showing how simple the userface is, but he started with shining stars on a black background. 

I would like to use it but don't know where to start?

1 hour ago, Martin Meredith said:

Hi

I don't know what software you're using but I wonder how much histogram manipulation you're doing? This will have a much greater effect than changing the individual sub exposure.

Here's a single 15s sub of M51 with little or no histogram manipulation

(all images from 8" f4 reflector + Lodestar X2 mono guide camera on non-guided alt-az mount)

and here's the same data with a different 'stretch' (sometimes called 'curves', or adjusting the 'mid point')

If you're not seeing any improvement with stacking, then perhaps the software is failing to align from one frame to the next? You will definitely see some improvement from 1 to 2 subs, then from 2 to 4, etc. Each doubling will create the the same amount of improvement.

Even so, if you don't manipulate the histogram appropriately, you won't necessarily see much improvement from stacking. Here's 4 subs stacked using no manipulation:

so barely any change from the single sub case. Here's the same 4 subs with a proper stretch:

and the improvement from the one sub case is obvious.

If your software allows you to save individual subs and then reload them later (many do), you could explore the histogram controls at leisure rather than during the rare clear nights... 

cheers

Martin

 

Thanks Martin,

I'm using sharpcap.

I haven't really played with the histogram much as I don't really understand yet. The one thing I did do was move the black level up to the start of the peaks.

The way you've explained it makes it seem like thats the direction I need to be going in.