How accurate is Stellarium Oculars view?

[Gissajob]

So, I'm trying to get an idea from Stellarium of what I can expect to see through my scope. I think I've set it upright. I have 3 eps - 20mm, 12.5mm and 6mm. If I use the 20mm set-up, it says I should be getting 45x magnification, which is what the scope instructions says. I then ask it to show me Jupiter and Saturn, and both of those look pretty much like I see through the scope.

BUT - I then go to M65 / M66, and they are huge in the Stellarium view - much bigger than either Jupiter or Saturn. This doesn't feel right to me. Am I expecting too much accuracy from Stellarium?

Alan

[estwing]

not sure how do you change the scope details...would love to know

[Gissajob]

not sure how do you change the scope details...would love to know

Well, there's a topic on here somewhere about it, but I sort of had a fiddle and I think I figured it out. To do the initial set-up, you do Configuration>Plugins, select Oculars and then click 'configure'. Once you're in that bit, you use the Eyepieces and Telescopes tabs to define your kit. Also, on the General tab tick the 'On-screen control panel' box. Re-boot Stellarium and you'll have a little control panel top right. When you click the first icon on there (the big circle) you get ocular view up. Click it again, it closes. And, you get two areas which show you which Ocular and Telescope it's simulating. There are little double arrowheads next to these - click on them and it cycles you through the kit you defined earlier.

Alan

[portedGoblin]

I use the Oculars plug in, but not with eyepieces but with CCDs. I have not found it inaccurate. I would be very surprised if such a bug hadn't been noticed yet.

[Steve Ward]

Saturn's about 18 second of arc across and M65 is about 8.5 minutes by 2.5 minutes , it's gonna look a lot bigger cos it is . . . . .

[tferrari]

Open stellarium's settings menu (left hand side of stellarium screen) select plugins, click oculars on left hand side, select 'load at startup' and press configure button. Inside of there you'll see the fields for adding eyepieces, scopes and CCDs. Populate those fields as necessary.

The default key combinations for accessing the CCD panel while an object/star etc. is selected in stellarium is ALT+O. From there you can select 'toggle CCD'. Press ALT+O again and you'll see the list of options for selecting your CCD and scope. For eyepieces (oculars portion of program), press CTRL+O instead of ALT+O. You can see key combinations inside of the ocars configure screen as described above.

I also believe Astronomyshed has a tutorial on youtube for the oculars plugin if my memory serves me correctly.

This is all from memory - not at my computer. Any questions, ask away!

[RikM]

So, I'm trying to get an idea from Stellarium of what I can expect to see through my scope. I think I've set it upright. I have 3 eps - 20mm, 12.5mm and 6mm. If I use the 20mm set-up, it says I should be getting 45x magnification, which is what the scope instructions says. I then ask it to show me Jupiter and Saturn, and both of those look pretty much like I see through the scope.

BUT - I then go to M65 / M66, and they are huge in the Stellarium view - much bigger than either Jupiter or Saturn. This doesn't feel right to me. Am I expecting too much accuracy from Stellarium?

Alan

I find the Stellarium Occulars plug in extremely accurate in terms of the field of view and the size of the objects. M65 / M66 are much bigger than Jupiter and Saturn. Where the view doesn't match real life, is in how bright the objects are and how much detail you will actually see. DSO's are for the most part very faint. Galaxies in particular are washed out by moonlight and light polution so you often only end up seeing the small nucleus/core and don't see the huge faint halo. The images used in Stellarium (and other FOV calculators) are long exposure images and totally nothing like what you will actually see with your own eyes.

[Gissajob]

Saturn's about 18 second of arc across and M65 is about 8.5 minutes by 2.5 minutes , it's gonna look a lot bigger cos it is . . . . .

OK, so I feel a learning opportunity coming on...

If M65 is much bigger than Saturn, why doesn't it stand out in the sky prominently? I'm guessing it's because it's simply not as bright?

Alan

[Steve Ward]

Pretty much ,

The size of these objects only really becomes apparent when seen with long exposure photos.

M31 , for example , looks like a small fuzzy patch to either the naked eye or through a scope , and what you are seeing is just the bright core of the galaxy.

It does in fact extend to about six Moon widths ( three degrees of arc ) but unless you take photos you'll never see the whole thing ( unless you have a very dark site and a 40" dob ... )

Comparison shot I made last year of the two ( separate images taken with same kit on same night )

[Gissajob]

Now I understand - that's very illuminating (apologies for the bad pun - couldn't resist).

Thanks Steve.

Alan