15 replies to this topic

[Professor2112]

Just got my first light with the rasa8 after waiting 6 months for all the pieces to my new rig to arrive.  Everything went well, but it was cold Saturday night(-10C), and I’m pretty sure it messed with my scrawny cheap USB cable I had going to my mount. I could plate solve my images in Nina, but the command to sync with the mount was failing, even though it was working before, when plate solving was failing due to me forgetting to change my FL from last session.. long story short, I ended up having a good session other than the fact I was not aiming at m81 + m82 and friends due to USB failure. I was almost 3 degrees off in RA and almost 2 in Dec. according to plate solving. I expected to get a nice pic of a star field, maybe a couple tiny back ground galaxies if I was lucky.. well, I think I lucked out and picked up random IFN from the m81 and m82 region.. I also must say how blown away I am at how good the image looks compared to my last ones with a dslr as far as just how clean they are. This is the first one of my pics I can zoom in really far to the pixel level and still see a smooth image. If someone can indeed confirm that this is IFN in the image and not noise or some other artefacts that would be amazing. Anyway, thanks for taking a look!

 

Asi295mc pro
Rasa 8
Cem70
No guiding

334x60sec. Exposures(3hrs, 54mins)
50 darks, no flats(haven’t gotten a dew shield yet)
Gain 121, offset 30

 

I blew out the brightest stars, so I’ll have to ease back on the exposure times and/or lower gain to full dynamic range mode even though they were only a min each lol. I’m used to my f/10 sct, this light bucket is a joy to use. I was so afraid of tilt issues after reading on forums LOL. I’d highly recommend it! 

 

The mount has also been fantastic. Up until now I’ve only used either my canon 60d/135mm lens, or the asi294/astromechanics ascom adapter/135mm lens on that mount which is a tiny load, but it tracked perfectly none the less.  I noticed no difference with the rasa8. Solid as a rock. The ipolar does a good job with polar alignment as well as my image has no discernible drift from first to last exposure over a 4 or more hr period.  Anyway, that’s all I got!

Clear skies everyone!! And may the kraken keep away from your imaging rigs!

 

I will post a full res version and the raw stack once I’m off work. 

Attached Thumbnails

• 

[RogeZ]

Unfortunately, I think this pumpkin nebula is a flat artifact from the 294MC. IFN is much harder than 3.5hrs...

[Professor2112]

RogeZ, on 23 Feb 2021 - 12:14 PM, said:

Unfortunately, I think this pumpkin nebula is a flat artifact from the 294MC. IFN is much harder than 3.5hrs...

Thanks for the input! That is very odd though, considering how deep the image did get to pick up those tiny tiny galaxies in the background. To me banding or artefacts happen either vertical or horizontal, these look natural, like tendrils of gas, that go diagonal bottom right to upper left(or top left to bottom right if you prefer haha). Even in the compressed image, you can zoom in and theres very little noise and the image looks very clean compared to my other images with much less integration time and frames using the same camera. Ive never seen an artefact like this before, with or without using flats. Im with you though that I thought for sure there was no way it could be IFN in 4 hours of total exposure, but then I remembered Im imaging at f/2 so I figured maybe there was a chance. When zoomed in its as if you can see structure, and not digital artefacts. If it is an artefact, it is a pretty cool one!

Edited by Professor2112, 23 February 2021 - 06:03 PM.

[Huangdi]

Unfortunately, I think this pumpkin nebula is a flat artifact from the 294MC. IFN is much harder than 3.5hrs...

You can easily pick up IFN with a system like that in 3.5 hours. You just need dark skies.

 

 

To the OP: how dark are your skies? If its above bortle 4, that most likely is not IFN.

 

Apart from that, you have pretty severe walking noise and the color is off. You need to fix these issues before you can hope to bring out IFN. Why aren't you guiding? It's pretty much necessary unless you're running a 10micron mount and even then, dithering has a lot of benefits.

 

Check out the attached image. It's 8 hours of Luminance with the RASA8, QHY183M under bortle 5 skies. The image is pretty bad but the IFN is real. To get a clean image of it, I'd recommend you get at least 10 hours of exposure. The brighter your skies, the longer it gets. 3 hours would be fine in Bortle 1...

Attached Thumbnails

• 

[Professor2112]

Huangdi, on 23 Feb 2021 - 2:46 PM, said:

You can easily pick up IFN with a system like that in 3.5 hours. You just need dark skies.


To the OP: how dark are your skies? If its above bortle 4, that most likely is not IFN.

Apart from that, you have pretty severe walking noise and the color is off. You need to fix these issues before you can hope to bring out IFN. Why aren't you guiding? It's pretty much necessary unless you're running a 10micron mount and even then, dithering has a lot of benefits.

Check out the attached image. It's 8 hours of Luminance with the RASA8, QHY183M under bortle 5 skies. The image is pretty bad but the IFN is real. To get a clean image of it, I'd recommend you get at least 10 hours of exposure. The brighter your skies, the longer it gets. 3 hours would be fine in Bortle 1...

Hey thanks for the input! First answer is my skies are bortle 4 where I took the image, the moon was also not out that night. The sky magnitude is approx. 20.51 according to Clear Outside. But yes, the colors are indeed off.. when I was processing the image, that pattern started to reveal itself, so I just did what I could to pull that out in order to present it here to figure out what it was. To answer the guiding question, I have a guiding setup, Im just waiting on the dovetail so I can mount it. Honestly I didnt ever think about walking noise.  The reason I want guiding is so I can avoid it. So youre saying those structures that look like nebula are actually walking noise? That would make sense why its diagonal. Its also a bit of a relief because its an easy fix once I have guiding going. I guess it looks so natural because the thermal noise and other sources are so minimal?

 

Oh, and how rude of me, nice looking image btw!  I want to add an asi294mm pro to my arsenal. I believe it would be a great fit to get either luminance or Ha data, then use the 294mc to get RGB data to combine with. 

Edited by Professor2112, 23 February 2021 - 05:58 PM.

[Professor2112]

Heres a link to the raw stack as promised.

 

https://www.dropbox....result.fit?dl=0

 

  I'm thinking one of/or a combination of three things are going on here.  Either all thats there is some weird artefacts/walking noise combo, I just over processed it, or, I did get a bit of IFN but its streaked with the walking noise.  Next session will have guiding, so that'll confirm or eliminate the walking noise issue.  I'm also liking that the stars dont look distorted or out of focus in different areas so it looks like there isnt any serious tilt and my back focus is correct.  There was some vignetting around the corners that I cropped out, but I know flats will easily correct for that.

Edited by Professor2112, 23 February 2021 - 10:26 PM.

[Huangdi]

Well it sure looks like it's walking noise. I'll take a look at your data later today or tomorrow.. Whenever I get the time. I'll get back to you 👍

[Professor2112]

Well it sure looks like it's walking noise. I'll take a look at your data later today or tomorrow.. Whenever I get the time. I'll get back to you

Hey thanks I appreciate it!  Im wondering is its ONLY walking noise and I didnt pick up anything? Or if the IFN has waking noise going thru it.. either way, I have a ZWO mini guidescope on its way this week, it was actually in stock! So my next session will be dithered! Lol!

[Professor2112]

So here’s something interesting... sat my cem70 on the table and decided to use the same cable I used that failed last imaging session in the -10c temps. It connects no problem. So it HAD to be the cold that caused the failure. Anyone else had this happen before? It’s a shame because if that cable hadn’t failed, I’d have had m81 center screen!  Oh well, there’s always next time!

[sharkmelley]

I suggest you plate solve your image then compare it to other images of the IFN in that region.  You'll soon know if yours is genuine or an artefact.

 

Mark

[andysea]

Looks almost identical in shape to what I had with my copy of the 294 color. https://www.cloudyni.../#entry10905014

[Professor2112]

I suggest you plate solve your image then compare it to other images of the IFN in that region.  You'll soon know if yours is genuine or an artefact.

 

Mark

I was actually thinking of doing that. Been trying to match stars with peoples m81/82 images. May as well have a computer do it for me haha. 

[Professor2112]

Looks almost identical in shape to what I had with my copy of the 294 color. https://www.cloudyni.../#entry10905014

Are you talking about what the camera looks like without flats? Or some artefacts?  I’m wondering since it’s my first astro camera but I also haven’t had that pattern before, but I also had flat calibration applied.  I’m just trying to figure it all out either way is all haha.  It would be cool if it was some IFN but I won’t be disappointed if it isn’t.  If you could find an example picture of what you mean that would be awesome! If you have any that is.  I think I’m going to be ordering the 294mm soon for my luminance data. The bin 1 mode would be so great with the rasa 8. 

[sharkmelley]

The area covered by your image can be found at the bottom left of this image:

https://discuss.pixl...d-a-comet/18325

and the right hand edge of this one:

https://www.webastro...82-et-c2019-y1/

 

The "IFN" in your image doesn't seem to match either so I think it's more likely a sensor artefact which would probably be cured with flat frames.

 

Mark

[Professor2112]

The area covered by your image can be found at the bottom left of this image:

https://discuss.pixl...d-a-comet/18325

and the right hand edge of this one:

https://www.webastro...82-et-c2019-y1/

 

The "IFN" in your image doesn't seem to match either so I think it's more likely a sensor artefact which would probably be cured with flat frames.

 

Mark

Thank you so much for the info! This is hugely helpful.  But alas the only parts that seemed to “match” are a couple of the dark patches.  So I bet a combination of proper flats and more integration would have pulled more out.  Next time I will be on target though, as I now know all I had to do that night was replace the usb with a not frozen one which I had, but assumed it was another issue.  Leo triplet is gonna be next I think. Where I image from I’m limited by what isn’t going to be blocked by trees to the south, more trees to the north.. I have a slice of sky in the area of the equator going east to west. Luckily Polaris is just above the trees so I am able to plate solve with the ipolar.  

 

Quick question about how you guys frame galaxy clusters/multiple targets in one frame...  where do you guys tell plate solving to center your image when the image center is somewhere in between the targets?  Such as bodes and friends, the best framing isn’t to center bodes, but somewhere in the middle of the main 3 galaxies.. how do you do that? I notice in ninas framing assistant you can click and drag your fov, is that all there is to it? Drag to where you want and then sync the mount? I didn’t get to play with any of those features because of my USB issues I was having. 

Edited by Professor2112, 25 February 2021 - 05:50 PM.

[Professor2112]

So I did the best I could to reprocess taking care to use proper colors.  I think the stars and tiny galaxies look much better.  Did my best to remove the artefacts as well.

 

Full Res - https://www.dropbox....rocess.tif?dl=0

 

 

Attached Thumbnails

• 

Edited by Professor2112, 25 February 2021 - 07:50 PM.