rohanpai

On 17/05/2022 at 18:39, david_taurus83 said:

did you take the darks with the camera on the scope?

hi @david_taurus83 - yes, i took this with the camera on the scope. I suspect there was light leak from near the OAG and I was taking these darks in daylight. I took darks again last night and they don't show this pattern anymore.

I am using ASI1600mm and captured dark frames at 300sec and camera cooled to -1C. When stretched, the frame shows a wavy pattern from top right corner.

Does this look like a light leak?

15 hours ago, alacant said:

There are hundreds thousands of them. Here are a few of the brighter ones:

Thanks. I was expecting them to be moving much more

I'll try different dither settings next time on the same target.

Weird enough, I used the same setup and setting to image the Carina nebula and this noise pattern didn't occur. The only difference was the sensor temperature (i wasn't cooling the camera for both sessions - so Carina was about 15C and Dragons of Ara was about 11C) and I did not have my dew heater strapped around the OTA for Carina.

On 08/05/2022 at 00:16, michael8554 said:

12 pixels is a common figure.

I have this as my settings in PHD2. I am not sure if PHD2 will do the minimum configured move and then go ahead with the next capture. Should I try changing this?

My imaging camera is a asi1600mm with 3.8um pixel size and guide camera is a asi120mc-s which is 3.75um pixel size.

On 08/05/2022 at 01:36, wimvb said:

If dithering works, you should see a hot pixel distribution similar to this. If the hot pixels are along a line, you can expect walking noise.

I used sum stacking and I don't see any hot pixels along a straight line

I was dithering using a asi120mc-s with OAG. I can try dithering to 12pixels and see if tht makes any difference.

5 hours ago, wimvb said:

f you stack the subs without pixel rejection, you will see hot pixels following  the dither pattern.

Hey mate

Not sure how I can stack without pixel rejection. Can you help with what settings to use in DSS or Siril or PixInsight? I've got all 3 running at the moment ..

5 hours ago, david_taurus83 said:

What equipment did you use? Even with dithering it won't eliminate all noise. I notice it more in the blue channel if I use my DSLR. 2 hours isn't a lot of integration either for narrowband data.

HI David

I will imaging using a WO ZS61 and ZWO 1600mm.

I gathered another 2 hours of data today. Stacked it all and see the same noise pattern on today's stack as well.

5 hours ago, ollypenrice said:

To my eye that looks electronic in origin rather than optical, so I'd put dew at the bottom of the list of suspects. Things to look into would include,

1) Do you see any trace of this type of noise in single subs?

2) Try stacking without darks, then without darks or flats, to see if they are introducing the noise. They may be.

3) Check your stacking parameters. Try different ones, ie Sigma, Median and Average.

4) Try a different stacking program. (You can download AstroArt for trial. It won't save but it's a great stacking-calibrating program.

There doesn't seem to be any very obvious object in the image. The stars are tight but what were you imaging? (My thought is that the image shown might have been stretched beyond its limit in search of an object which isn't there.)

Olly

Hi Olly

1) Do you see any trace of this type of noise in single subs?
>> Yes. I can see some on a single sub as well. I have attached a single sub with Ha filter and Oiii filter.

2) Try stacking without darks, then without darks or flats, to see if they are introducing the noise. They may be.
>> I tried this and got the same result. The stacked image shows the same noise pattern

3) Check your stacking parameters. Try different ones, ie Sigma, Median and Average.
4) Try a different stacking program. (You can download AstroArt for trial. It won't save but it's a great stacking-calibrating program.
>> I tried Siril and DSS and PixInsight. All 3 gave similar results

I was imaging the Dragons of Ara (NCG 6188). I did a auto stretch in Siril and PixInsight after stacking and saw this noise. Even with manual stretch, I could see the noise start to show up quickly.

Oiii filter.fit ha filter.fit

Need some guidance here..

I got about 2 hours of data in total with Ha and Oiii filter. I had good polar alignment, guiding was going well and I was dithering after every image.

I stacked it all this morning with darks and flats and the image has walking noise.

If I am dithering, should it not eliminate the walking noise? Can this be due to dew?

Hi @michael8554 -

I tried your recommendation of pulling the camera out of the focuser and managed to get focus. So I need more distance between the focuser flange and the sensor.

Hi all

I connected a Touptek gpcmos02000kpa to Skywatcher 200PDS (hoping to get some videos of the moon), but could not get any focus.

I suspect I need to have a certain backfocus distance to get image on the camera sensor. Anyone has tried this setup? What is the recommended backfocus distance?

Thanks in advance.

Rohan.

Thanks, @malc-c

Hello!

Would this power supply adapter work for a HEQ5 pro?

10A/8A/6A Power Supply Adapter AC 100 - 240V to DC 12V Transformer Home Office - Kogan.com

Thanks!

Rohan

Hi @Dougie Smart - 

I bought a Bresser full HD camera. Installed Toupsky and the ASCOM driver for Bresser. Connected it to my laptop via the cable provided with the camera. Opened Toupsky - it did not detect the camera. Opened SharpCap and it did not detect the ASCOM Bresser camera...

Did you have to do anything different to get the camera connected?

There is a little red indicator at the back of the camera. Does that turn on when your camera is detected, or is that only when guiding?

Thanks Alan. Will try it out …

I connected a Nikon D5300 to Zenithstar 61 using a T-mount and 2” adapter (no flattener). I couldn’t get focus even when the focuser tube completely moved out.

Has anyone else faced this? Do I need extender tubes to move the camera more behind?
 

thanks!

Would taking photos using the monochrome setting in a DSLR and LRGB filters give the same outcome as using a dedicated astro mono camera and LRGB filters? 🤔

Tried it, didn't work

1. All the metal and electricals from the mount interferes with the compass on the phone..

2. I was using HEQ5-pro. The Az movement using the screws does not have enough movement to swing from the closest visible star to Octanis (this may be a user error as well). But with the light pollution that I have in the south direction, my closest visible star is Alpha Centauri, Hadar and Acrux

But I'll give it another try when I get clear night in Sydney...

Thanks @alacant

I’m using a Nikon D5300 with Skywatcher 200PDS for imaging.

do I need a separate t2 to 1.25” filter adapter to use a filter for imaging? I am not looking to buy the clip-in filters.

I was using a 50mm prime pointing towards the southern pleiades. Focus was good

Set at F/2, 5 sec exposure

The star pattern was weird - the stars were trailing towards the outside. And this wasn't just with the stars in the corners.. began right at the centre. 

Is this due to stopping the lens at F2?

Has anyone tried the new Laser/Hop align feature on PS Align pro app?

Seems pretty useful for people like me who cannot see the Octans, thanks to all the light pollution.

Hi @Gaurav Mk - yep. Tried it all and still didn't get focus.

One thing I realized last night was that with all collimation, my primary mirror has moved way in - beyond the depth of the locking screw. I am going to reset the mirror, re-collimate and then try the focus. Waiting for clear skies here in Sydney.

@bottletopburly - will try tonight (hopefully will get some clear skies!)

Hi @bottletopburly - these are the pictures. I tried with the 1.25in holder between the t-ring and focuser tube which didn't work either. If this is the correct setup, then I am going to give this a try again tonight.

Hi @Astrid - this focuser tube wasn't locked. I was able to move the focuser.