ZWO ASI533MM-Pro for DSO

[Bletherer]

After spending quite a lot of time using a ZWO planetary camera I decided to try out the ASI533.

So far this has gone well - I used the moon to get it in focus, and by varying the exposure/gain settings I'm at a point where I can resolve individual stars so I think I'm in business. I'm hoping to try it out more thoroughly in the next few weeks with the goal of imaging some "easy" targets.

I have never tried DSO photography before. I use the zwo 120mm/guide scope for alignment and tracking and this usually works ok and I have the offset to ensure it centres on the ASI533 viewing area.

But I'm a bit nervous that I could be trying to image stack a DSO I can't see at all on the laptop and that I might actually be in the wrong place. Does anyone have general advice on settings that would help me resolve more detail of the DSO/region with shorter exposures to do a reality check before proper long-exposure recording?

[Gfischer]

Congratulations on the 533 I have one and love it. You didn’t mention the scope you are using for imaging. If your mount is a go to the object you select should be in imaging area. This assumes you setup mount alignment correctly. I don’t use a goto mount but sharpcap does an excellent job plate solving and using the push to tool I can put target in center. Start imaging on bright objects first to get used to controls. Have fun with your exploration!

[Bletherer]

Thanks! I'm using a Celestron 8inch SCT on a VX Equatorial mount.

I'm pretty happy with the inbuilt plate-solving go-to features, but I do all this backyard in a moderately light polluted area so sometimes the solving can be a bit fiddly. Obviously if you're imaging a planet and its not in the FOV of the camera it is VERY obvious something is wrong but I'm concerned that's not true for DSOs. What targets would be best then for "yep, I'm definitely in the right place for ___"?

[admin]

Hi,

the IMX533 is a great sensor, so you should enjoy using it for deep sky work. You can also use it for planets too, as the frame rate is good if you put it into ROI mode (and the bigger sensor makes it much easier to find the planet in the first place).

There are two tools that will help you a lot to find deep sky targets...

1) The 'Plate Solve and Sync' tool - use that after the initial GOTO the target, and providing the plate solve works, SharpCap should put the target in the middle of the image. You can always check by running it a second time (if the first was right, the second should do practically nothing).

2) The auto-stretch (lightning bolt) tool in the mini histogram area on the right - https://docs.sharpcap.co.uk/4.1/#Display%20Stretch . This applies a stretch to the displayed image (doesn't affect saved images), which helps make the faint targets visible in single images with relatively short exposures. Whatever you are looking at will still most likely be faint, and very noisy, but you should be able to see it.

cheers, and clear skies!

Robin

[Gfischer]

Bietherer,
With your native 2000 mm fl bright globulars are a great start. Maybe M22, M5, M15. These will show up on your screen with even a 4sec exposure.