6 replies to this topic

[WxObserver]

Started imaging the Leo Triplet last night, and there was something in the corner of the frame that I first thought was maybe a problem with dark frames, but now I think it may be stray light from Chertan, which is only just barely out of the FOV.

 

This is taken with the new Askar SQA70, and I have a couple of questions:

 

• Is this typical for a good astrograph, or does this reflect poorly on the SQA70 (pun intended )?
• Should I adjust the FOV to include Chertan...will that get rid of this? Seems like it's too close to the edge to think about an extened lens hood.

Here's a copy of the photobombed frame pasted on top of a Stellarium display showing (I think) that this is being caused by Chertan...

 

[PIEJr]

Never blame your equipment. After all it would be in a case on a shelf if not for you. 

 

If it were me, I'd turn the frame 45 degrees CCW, and maybe slide it Southwest (Towards the lower right corner) to see if I couldn't slip away from that Charlatan star.

Doing framing is why I finally invested it a rotator after all these years.

 

You might be able to post process that flare out. But I'd take another shot at it tonight, and move your frame towards Tsze Tseang (Away from Chertan).

 

Just keep swimming, you're doing fine.

Are you plate solving yet? Plate solving could get the triplet dead center for you.

 

And remember, not all Hamburgers come out the same.  

Edited by PIEJr, 28 April 2025 - 03:17 PM.

[WxObserver]

Thanks for the suggestion. The SQA70 does have a built-in rotator and I worked out a rotation that would put Chertan perpendicular to the top of the frame, and I can reposition the shot slightly so that the frame is equidistant between Chertan and Tsze Tseang. I'm not sure, but there may have been some stray light from Tsze in the frame as well -- not as much, but they're both about the same mag, so I'll split the difference.

 

Odds are good it will be clear tonight, maybe worse seeing, but certainly good enough to test out the idea.

 

Plate solving was one of the first things I learned to do, and it was well worth the effort. Can't see Polaris here and polar align via plate solving is super easy and fast to do now with APT. Not to mention being able to plan out a shot in Stellarium and go exactly to that spot for imaging. Plus, imaging runs on different nights always wind up with almost exactly the same framing, so there's very little wasted image real estate after integration.

[PIEJr]

Thanks for the suggestion. The SQA70 does have a built-in rotator and I worked out a rotation that would put Chertan perpendicular to the top of the frame, and I can reposition the shot slightly so that the frame is equidistant between Chertan and Tsze Tseang. I'm not sure, but there may have been some stray light from Tsze in the frame as well -- not as much, but they're both about the same mag, so I'll split the difference.

 

Odds are good it will be clear tonight, maybe worse seeing, but certainly good enough to test out the idea.

 

Plate solving was one of the first things I learned to do, and it was well worth the effort. Can't see Polaris here and polar align via plate solving is super easy and fast to do now with APT. Not to mention being able to plan out a shot in Stellarium and go exactly to that spot for imaging. Plus, imaging runs on different nights always wind up with almost exactly the same framing, so there's very little wasted image real estate after integration.

Sounds like you are doing great.

Have you tried NINA? I really like it now that it has the equipment that works with it.

I made some course changes and upgrades after I decided to get NINA to work for me.

I think I'm envious of your Petzval telescope.

 

Sometimes I get some odd thing, or star spires and it takes time to sort them out.

I had a realty check after several nights of degraded imaging.

I finally turned my telescope around and looked in the big end. The foreword baffle had somehow turned 90 degrees.

Mike at Astonomics walked me through turning it back. and it has stayed set every since. (Maybe shipping had knocked it ajar?)

 

I'd bet you just happened to get some stray glare that may have been from Chertan.

More play is advised.

 

It's supposed to be clear here tonight. So I'm itching to get back at my AP.

I hate cloudy dry spells. Often brings out all sorts of gremlins.

Hope your skies are great and that anomaly was just some ghost.

Clear Skies!

 

What are you using with your scope? I'm currently using my ASI2600MC Pro with my AT130MC and love it.

 

Just thought, maybe if your sensor could see more of the bright stars it would auto adjust the flare out. On it's own.

It might be interesting to do a live view and swing it to and frow.

Have you talked to Askar yet?

Honestly, I'd play with it more. But that's just me, trying to figure it out.

Some objects just seem to act weird.

Good Luck!

[WxObserver]

Thanks for mentioning the camera you're using -- it resulted in me figuring out what was going on here. Not exactly, but with more certainty than before.

 

I'm using an ASI294MM with small sensor -- 19x13mm, but the telescope is designed to handle full frame sensors -- 36x24mm. Checking the FOV for the full-frame sensor in Stellarium (see image below) with the original orientation reveals that Chertan is well within the frame of a full size sensor. That means, I suspect, that focused light from Chertan was getting diffracted and/or reflected by something in the imaging train -- either the filter wheel, filter, or something on the camera. In any case, it most certainly is not a problem with the telescope.

 

Managed to get a few frames with the new configuration last night before some high clouds moved in. That uses an 18-degree rotation from the RA axis, centered on M66. Below is the Stellarium depiction for that setup with a full-frame sensor, and neither Chertan or Tsze... are within the frame any longer.

 

So this it turns out may be a useful check to make when setting up a shot. Have a look at the full-frame FOV and make sure there aren't any bright stars within that FOV, but outside the ASI294MM FOV.

 

I haven't tried NINA yet -- sounds like it has some good features, but my brain's invested in APT right now and I don't feel like changing just yet. APT does pretty much everthing I want it to, but at some point in the future I'll have a look at NINA too.

 

Here's the FOV for a full-frame sensor in the original orientation, with Chertan well within the field.

 

 

This is the full-frame FOV with the new orientation.

 

 

And here's a stack of 7 frames in red from last night, not enough data to get rid of the satellite tracks yet, but there's no hint of light creeping in from Chertan now.

 

Edited by WxObserver, 29 April 2025 - 12:22 PM.

[PIEJr]

Well the result looks good, and no flares! 

 

As you go along you will figure out what will get you the results you want.

In my signature is my equipment listed I'm using.

I tried mono for a few years but tired of the processing it needed.

So I took a giant step back into one shot color again. I'm much happier getting my "instant" results. 

The ASI2600MC Pro camera seems to be popular, or was, so I decided to jump back into OSC with it on my AT130mm EDT telescope.

I'm more of a Nebula chaser, so square sensors are better for that. But the APS-C sensor has opened up many new views for me to rerun with old favorites.

The APS-C gives a large really clear view and can be mosaiced for things like the North American Nebula, which proves to be largo for my present telescope.

 

I've never owned a full frame camera. My DSLR was an APS-C sensor. But my Nebula victims want for something smaller and more centered.

My Atik Infinity a friend loaned, and then sold me was the second camera I owned and it started off the first night with the first picture as near perfect with my ED80T CF telescope.

Album: Atik Infinity OSC Images

3 images

0 comments

 

It has a quite small sensor in it. I really enjoyed it.

But Atik sent out an updated software both my friend and I installed and it really messed up our Infinity cameras.

The software engineer insisted it could not be his update. My friend came up with a cure for the bad update that got both of us working again. (He had a stable of Atik Cameras.)

As far as I remember it still works, but it is mothballed for the time being.

I have enough hardships with this sport as it is, without hopping around between my cameras.

I did try my ASI1600MM Pro at the beginning of this galaxy season wondering how it might work for that. But I no sooner got it transferable with the 2600MC than I decided to go back to the 2600MC and stay there.

 

Maybe when I win the lottery I'll get enough mounts and telescopes that it can be a simple Plug N Play choice of what I pick for the evening.

Fat chance, since I don't play the lottery. I accept that I'm a looser without proving it. 

 

Anyway, I think you've solved the mystery of Chertan the Hamburger destroyer.  

 

I was going to try the Leo Triplet. But after coming home from a week long visit to the Daughter and Son-In-Laws house in Washington (State), and cloudy Spring weather, when I put my telescope back on my mount my Polar Alignment was way off.

I forgot to do a Polar Alignment and wasted my 2 clear nights scratching my head. Until I realized my mistake. Last night I got my Polar Alignment done, and a new Modeling (Star Alignment) just in time for the cloudy spring weather to return.

Marvelous! I am my own worst enemy. 

 

 

[WxObserver]

Ah yes, tales of rabbit holes and the equipment we find in them!

 

I'm more interested in nebulae too. Would like to do a large mosaic of the entire Orion complex later this year. That should be fun. At my location, and with the obstructions around here, it's the spring doldrums, so I'm stuck with galactic targets for the next month or so. It's good practice at a minimum.

 

Started with a Canon 5D Mark II and 400mm telephoto lens. Soon tired of focusing, but couldn't justify investing in the remote focus gear. It felt like that would be a bit akin to putting lipstick on a pig. Also realized that sensor calibration with darks was very sensitive to temperature and there was no easy way to cool or regulate the temperature. Folks have done that but that wasn't for me.

 

Then I found a used ASI1600MM with 8-position EFW and L/R/G/B/S/H/O filters at a reasonable price, but still had the 400mm Canon lens. Next comes the discovery that microlensing in the ASI1600MM from Alnitak when imaging IC434 was really objectionable.

 

Then, finding that the Canon lens had too much CA/coma for my taste ends up in the Askar refractor shows up on my doorstep one day.

 

Upgrading the filter wheel to work with a larger sensor would be very expensive due to cost of NB filters, so the camera upgrade option I chose was the ASI294MM.

 

Anyway, that's where things are at now, and I'm presently busy climbing the PI learning curve cliff.