badgerchap

52 minutes ago, mcrowle said:

Let's hope NEOWISE puts on a great show (and that the weather co-operates)!

I have a lot of appendages crossed!

Comet C/2020 F3 (NEOWISE) is beginning to look pretty tempting. Currently Mag. +2.3 and brightening, this is looking like a very tasty target for the middle of July IF it can survive its perihelion.

(link to comet's Twitter account)

I've never imaged a bright comet before, and I'm not really sure what setup is best. My initial instinct was to make use of my C8 and its long focal length, but if the comet is going to be large and diffuse then maybe the short FL of my 6" F4  Newt even my 66mm semi-Apo would be preferable. Can anyone shed light on the best approach to imaging an object like this?

Many thanks in advance,

Badgerchap

Projected to reach +0.5

🤞🤞🤞

I have that kind of thing lying around. What kind of temperature is correct? 
 

I've never used a dew heater before!  A new experience now I'm using a Cat.

Hi all,

I recently bought a second hand scope which had with it, among other bits 'n' bobs, a dew heater tape. This is unlabelled with no manufacturer etc. I want to power it (I'll build something with stuff lying around) but I have no indication as to what voltage to use etc. Finding the resistance is easy enough, but what wattage should I be aiming for? I'm using it on a Celestron C8 if that makes any difference.

Many thanks,

Badgerchap

Welcome to 3D printing! Such a joy seeing your creations emerging upon the build plate before your very eyes! 

I'm impressed with the thread pitch you managed from an FDM printer, that's great going! I have a resin printer that can perhaps go a smidge smaller on a very, very good day, but would be a lot less rugged than what you'll have produced. Great work. Might have to get myself an Ender too.....  

1 hour ago, pete_l said:

Sounds sensible.
Given that it is quick, cheap and easy to test if this is sufficient there is nothing to lose by giving it a try. If it works, then great! You have saved yourself a lot of unnecessary work.  If not, you are no worse off (apart from the cost of a few paving slabs).

Got the slabs from a neighbour, so even they're no cost to sacrifice!

8 hours ago, JamesF said:

I'd prefer something that wouldn't move if it were bumped and I'd not lay the slabs on bare earth, but other than that I think it may well work just fine.

James

Yes, when I say I'll not pour concrete at all, I may bend that a little to mean "no more than necessary to lay a few slabs properly"!

The risk of bumping is certainly a concern, but if it only happens now and again I think I can live with it.

I’ve a small extension of this question.

I live in the middle of nowhere with no road other than our drive (serving 10 houses) within about a third of a mile. Even this road is dead as a doornail past about 8 p.m., like, completely dead. I want a remote obsy in my garden, about ten metres from the house. I’m thinking that really, I don’t need to pour concrete AT ALL. In fact, apart from a sporadic need to redo the polar alignment, I think sticking my EQ6 tripod on a few slabs will probably do the job.

Now, anyone up for telling me how wrong I am?

EDIT: i should also mention I intend imaging at a pretty stumpy FL: 600mm at F4

5 hours ago, symmetal said:

If your image is good enough that only the planets rotation is causing it to look a bit blurry I think you'd be very happy. 😁

Now that is a remarkably good point! 🤣

6 minutes ago, symmetal said:

 

The drawback with DSLR videos is that they are lossy compressed, mp4 or similar, so stacking can't do such a good job  as using uncompressed videos but should still give a reasonable image. If your DSLR can do centre cut-out videos where the central 1920 x 1080 pixels (or whatever the video resolution is) are used for the video instead of downscaling the full frame, you'll get a larger image. Canon camera users can install the 'Magic Lantern' firmware which enables centre cut-out videos.

Alan

I was recently reading that you should take a series of stills rather than a video with a DSLR, but this seems unlikely to be successful with Jupiter as getting enough images without showing rotation whilst also avoiding shutter vibrations seems unlikely, Does that seem correct?

Just now, maw lod qan said:

Never surrender, never give up!

When everything falls into place you find yourself smiling and saying "oh yeah!"

Yep, I remember getting that when I got my first Horsehead

12 minutes ago, symmetal said:

 

A high frame rate just means you can get your 1000 frames or more quicker. It doesn't by itself make the image better. It just means there's less a chance of clouds etc. upsetting the video. With Jupiter however, too long a video, over several minutes, will lead to image blurring due to planet rotation.

Alan

Hi Alan, thanks for that, plenty of stuff for me to work with in there. I suspected as much with the camera.

I do have a DSLR though which I use for DSO imaging. I was considering using that instead as it's colour, but it also has a slightly larger pixel size (5.2 um vs. 2.2 um). Would you expect this to cause a serious decrease in resulting image quality for an otherwise identical setup? I don't really have much of a feel for this yet!

Thanks

Ah good, thought so. Would be a bit of a faff otherwise! 

Excellent, thanks Carole, I'll give that a try next time the sky elves deign to let me see past the clouds again!

4 minutes ago, carastro said:

Or you can make a Y mask dead easy.

Oh thanks, not heard of that approach before! Stupid question: is the 'Y' hole or mask? I ask because if it's hole the middle would need supporting?

Certainly seems like a dark art! 

I can certainly reveal the moons by over exposing, so I'll try using them to focus, although I don't have a Bhatinov or a printer to help me make one. Still, they might be easier to focus than the disc of Jupiter.

Hi all,

I don't really like posting "what am I doing wrong" type posts, but I'm getting pretty frustrated with planetary AP so rather than pull any more hair out, I'm succumbing to the siren-call of SGL and i ts ever knowledgeable denizens.

Enclosed are my two best planetary images to date, both taken as 200 frames through a Celestron C8 & Celestron Ultima 2x Barlow with a monochrome uEye ui-1480le-m-hq (link: https://en.ids-imaging.com/store/ui-1480le-rev-2.html). The camera's not ideal due to its low frame rate, but I don't think it's the limiting factor here.

Data processed in PIPP and Autostakkert!3, roughly following JamesF's excellent guide: https://stargazerslounge.com/topic/184821-beginners-guide-to-stacking-planetary-images-with-autostakkert2/

I'm getting frustrated as I keep seeing other people's 'first planetary images' and they're routinely far superior to mine despite using more modest equipment and by people with far less astronomical experience than myself who, with the exception of planetary imaging, has been at this game for about 12 years now.

It's not all bad; I can just about make out the hint of some detail where the Cassini division should be, and Jupiter isn't quite a mere grey disc, but still, I somewhat hoped for more. I suspect that focus is at least part of my issue, so as well as the general "what am I doing wrong", there's also a question about how people tend to focus for planetary imaging.

Thanks in advance for any tips or tricks anyone can give!

Thanks @Timebandit, I'll keep a lookout on the second hand market :) 

Thanks @DeanCJ I'll look them and the review up!

12 hours ago, Louis D said:

And no fixed focal length eyepiece can be nearly instantly adjusted to match its focal length to the current seeing conditions like a zoom can.

Nice, I hadn't considered the adjustability with regards to seeing.

Thanks all.

I've always been suspicious of zoom EPs. I've heard that they're never as good as the equivalent fixed focal length lenses. Is this true, or are these Baaders high enough quality to avoid it?

2 hours ago, John said:

Ah, yes I understand now. On a dobsonian mount the 12 inch F/5's are very good for visual observing. Not for imaging though !

 

Indeed. One of my current projects is to convert it to a truss tube Dob. I might actually use it if it's more convenient!

7 hours ago, John said:

You don't really need a barlow for visual with a 2000mm focal length scope.

The best views I've had yet have been with the 40mm! Low mag but crystal clear. The barlow is useful as my smaller FL EPs are rubbish. I can see it being obsolete with better EPs.

8 hours ago, Cosmic Geoff said:

 I also have a set of Celestron X-cels, which are okay but don't show a life-changing improvement compared with the Plossls.

I somewhat suspected that, and I guess the subsequent jump to the Luminos would be even less significant

3 hours ago, John said:

A good 8 inch SCT can be very satisfying.

Slightly surprised that your 12 inch newtonian was not also delivering excellent views though but the SCT format is much more compact of course.

 

The problem with the 12" has always been stability rather than optics. The NEQ6 just isn't up to the job of controlling that beast. A sparrow farting within 50' seems to be enough to set it wobbling!