pipnina

28 minutes ago, Leeps said:

You seem to get the same swirly rainbow noise pattern that I get... Any idea what causes it? I thought it was due to my poor flats. This is a lovely job

I think my flats were probably wrong somehow. I never seem to get them right but I don't know what I'm doing wrong. I don't get this pattern when I use no calibration frames.

Nice report and I'm glad you got yo make use of the recent clear spell!

That second photo makes me think of the year 1968 for some reason...

1 minute ago, Dan13 said:

130pds, my first try at orion during this week.

Hello and welcome!

It's best to convert finished images to jpeg or png so that it can be viewed more easily.

I posted the result of my 4 hour data the other day, but as the conditions were good last night I figured returning to the same subject wouldn't hurt.

Still got some issues in processing. Flats look like they're overcompensating though I kept the histogram within the recommended range and they appear to correct properly when used on a single raw image in rawtherapee. I'm pretty happy with this over all however.

50 minutes ago, vlaiv said:

-snip-

 

An excellent explanation!

Kappa-sigma always gave me better results than the more plain methods in DSS, but I never knew what the settings were for.

Thanks for taking the time to write that!

3 hours ago, vlaiv said:

Kappa is sigma multiplier - above is two sigma range. Number of iterations is used to determine sigma and do clipping. In each iteration - all remaining values are averaged and standard deviation is calculated. Only pixel values that lie in avg +/- kappa*sigma range are "passed" to next iteration. Average value in last iteration is result of stacking for that particular pixel.

Above 2.00 and 5 settings are quite aggressive. Out of 100 subs, it will on average leave only ~68.3% samples and reduce SNR improvement from x10 to  ~ x3.85 if all subs are good and without issues!

(in each turn it will throw away ~32% samples and it will do that 5 times).

Much better settings would be - 3.0 and 3. Out of 100 subs that would reduce SNR improvement from x10 to x9.955

So if I get this right, kappa=1 would throw away all but the most consistent 33% of pixel values? While kappa=3 would only throw away 0.27%? And if that's by 5 iterations, it throws away 0.27% five times?

Does this mean, for purely hot pixel removal, it's best to use kappa=3 and iterations 2-5? Does low kappa severely limit benefits of stacking for "going deep" into images or preventing faint details from emerging?

The good weather continues and so I recharged my camera's batteries and set sights for M81 and M82 last night. I hoped to get in the order of 6 or more hours of images from it but at some point the 130-PDS impacted the tripod leg and it lost tracking, then the camera battery ran out, so I got just over 4 hours in the end. I'm relatively happy with the result though, looks relatively clean and free of my camera's usual defects (I shifted the mount by a minute or so after 2 hours). I should probably look into investing in pixInsight to get pictures like this in a better state since I think editing is my big bottleneck right now, next to my camera being unsuitable (hence no red plumes coming from M82 )

I used Aldebaran, and Procyon to test my focus and tracking, not the greatest images but nice star fields anyway, or so I think...

And of course a single 30-second exposure of M42, because it's impossible not to while it's still here!

I hope you guys had similar luck last night with the sky! And perhaps better luck than I with equipment 😛

41 minutes ago, lenscap said:

In the Synscan V4 Manual have a look at Section 5.8 User defined objects.

40 minutes ago, carastro said:

Yes, in the handset where you get a menu for choosing named star, scroll down with the arrows until you get to User objects, then enter the co-ordinates.

Carole  

Excellent! Thanks! I don't know what happened to my manual since the kitchen redo in January moved just about everything else in the house too ha.

Thanks again and hope you're all well.

It's very convenient that the handset can slew to catalogued targets automatically, but for a lot of pictures I'm trying to frame two objects at once. Is it possible to dial in a specific set of RA/DEC coordinates straight into the SynScan handset so I can reach the same location repeatably? I know people do it with the computers but I can't plug mine in (no adaptor)...

I can't find anything in the menus of my HEQ5-PRO to do this with... Help!

Had a few technical issues with the mount but I got it to a mostly satisfactory condition after an hour or two. Unfortunately i forgot to charge my double battery holder in my nikon so it only lasted about two hours into the imaging session and I had to cut it short

Hope the rest of you are getting some luck with the sky at the moment. Summer fast approaches and I for one hope to make the most of galaxy season

I think I've improved it... I got the "polaris position in scope" and the other stat it gives you after setting date/time/lat/long so I put polaris on the wrong side of the polar scope...

Still, I didn't think it would make that big of a difference...

I just set up my HEQ5 to catch some snaps while the weather is good. But despite double checking the balance of both axis and that the clutches are tight the scope still drifts noticably (can almost watch it!) in very little time.

What possible other causes could there be? I'm fairly certain my polar alignment cant be that bad! At this rate I'll loose another night of imaging to equipment issues

Any ideas to test welcome! Thanks!

14 minutes ago, Whirlwind said:

Are you intending to use the 250PX for imaging based on your profile or is there something else you intend to use?

It seems I never updated my profile when I got the imaging setup earlier this year, I'll have to edit that!

I have a HEQ5-PRO and a 130-PDS with Baader Mk3 coma corrector that I currently use for photography. My 250PX sits on a dob and I use that for visual, though I've tried to get a few sneaky planet photos through it.

Hi guys! I am hoping to move into proper astrocam imaging this winter and have been looking at the different options available. The Atik Horizon and ZWO ASI 1600MM-pro have caught my eye due to having fair sized sensors for the price, but which makes more sense to use?

They both seem to have the same size sensor with the same pixel size, though the ZWO is cheaper in mono form than the Atik. I have heard that ZWO equipment can also be operated wirelessly with another attachment, which could make adding a guiding cam even more convenient if I got a ZWO + ZWO?

My current camera is an old Nikon 3200, which has the same pixel scale as these cameras but a larger sensor. Would any reducing lens be useful to reduce the pixel scale some since I always binned my Nikon 2x2 anyway?

Thanks

ALMA can have a 16KM diameter with its movable telescopes. Perhaps I'm misunderstanding something or this video has overlooked it?

1 hour ago, DaveS said:

Cooled astrocam, yes. Probably CMOS unless you can afford £2k+ just for the camera. At the same time GUIDING. You haven't specifically said you have a guiding set up, but if you don't you will find it makes all the difference, even with a basic DSLR. With a 130PD-S you can piggyback it on a second dovetail opposite the main one..

Is there any way you can leave your mount at least set up? Telegizmos 365 covers are Very good and available from our favourite supplier.

Although I don't have direct experience of it (Yet) the ASIAir looks to be a very good semi-remote solution that will (Supposedly) allow you to control mount and camera from a smartphone or tablet. The only negative is that it appears to be locked to ASI cameras, but as first cooled cameras they look to be a good option.

Guiding is definitely something I need to look into! Thanks for reminding me.

I suppose I could leave the mount itself outside between nights with a cover. But it being soft ground I do wonder if it might be at risk of shifting over time (I don't have a good concrete space to put it), also the risk of theft while mild given my area and the setup location always lingers in the mind. But I'll definitely look into those covers!

If there isn't a good dedicated system for remote telescope control, maybe I could use a Raspberry PI to control the whole setup (Guiding/Mount movement/Camera) while the expensive computer sits safely indoors?

Thanks for the response

I always like seeing the brown dust around this nebula! A wonderful photo.

Hello! I've been gone for a while but now that the dark nights are upon us again I have been thinking more and more about my dusty astrophotography setup, especially since my coworkers recently saw my previous astro pics and wanted more! Sadly the weather over the last month has not been welcoming but I hope to become ready for the winter and spring ahead!

Currently I have a fairly simple HEQ5-PRO, Nikon 3200, and 130-PDS. I have been thinking about possible upgrades to this which would make it either out right better or easier to setup, but I felt I should ask for ideas from the experts!

The first thing I want to change is to move to a proper astrocam. The Nikon has been a great and cheap way to get started but it just doesn't keep pace with the rest of the kit. The Atik Horizon CMOS seems like a good direct replacement as it has the same pixel scale as my Nikon and I'd not lose too much FOV from differences in resolution, while gaining the benefits of active cooling and mono+Ha sensitivity. But maybe for my 130-650 telescope a bigger pixel scale would make better use of my field?

The other thing I must consider is setup time. Getting my HEQ5-PRO polar aligned and star aligned feels like a lengthy process with consulting the scope, then 3-star align, then scope again seemingly making no progress past 5". Is there any kit I could use to make this process less tedious?

I have a laptop I can use to control the mount and camera with. But ideally I could control both remotely? I seem to always use my photography equipment in my back garden which is within wifi range. I have heard of wifi modules for these things but don't know how universal or practical they are...

If I get the mono camera, I would want to get filters eventually, but I feel like I'd want to buy filter equipment once I am already comfortable with the astrocam so i don't think I'll buy any yet.

What do you guys think? The choice and possibilities for equipment are vast and there is much to consider... Higher quality pictures of the universe are in my future I hope! Thanks

Hi guys, took this image last night of M101 but it is in dire need of some flats as you can see.

What method do you guys use to take flats with the 130-PDS that minimises adding more tray light than you started with? last time I tried I got a gradient from one side of the image to the other...

Something like this might provide a good surface to shoot at for flats? https://www.amazon.co.uk/32-Inch-Portable-Translucent-Collapsible-Reflector/dp/B002ZIVKAE/ref=sr_1_1_sspa?ie=UTF8&qid=1546970257&sr=8-1-spons&keywords=photographic+reflector&psc=1

Also, flats don't need a perfectly reflective surface because your lens should be focused at infinity while the target is considerably closer.

When it comes to dew shields, what are you guys using? Off-the-shelf solutions or something more DIY?

Finding this thread just makes me more excited for the coming darkness! I got to do a few tests with my 130-PDS (hopefully I've got the hang of it all now!) during and just before summer twilight. Not sure what I'm going to photograph first though. My camera has pitiful Ha response (One day I'll complete the build with OAG and a cooled CMOS...) and the central milky way nebulae (M8, M16 etc) are too low down for me to image (without exposing the precious to the road and pavement... and street lamp glare!)

On a side note, has anyone else found the 130-PDS prone to stray light? In an image I took recently I noticed a gradient in the image that seemed too "sharp" to be vignetting or sky gradients. (The glowing pale lobe to the left hand side)

Are there measures that can be taken to prevent this?

Being held down by gravity alone, I would be mortified at the thought of mine tipping over since we're at 51-56 degrees north in the uk!

You seem to have done a splendid job of it though. You'd think it was off-the-shelf by Meade, made specifically for that scope!

Does only pixel scale matter for guidescopes, or is a guidescope of certain size relative to main telescope aperture also required?

Pipnina

A Dob needs to cool and be columated. So, yes, no screwing stuff together. But a little Frac on a simple manual mount already assembled is the fastest. I've got an ED80 on a AZ3 which stays up for most of the time.

If I has to assemble from scratch, the dob would win hands down.

Paul

So from my setup, something like a 10/12" dob would be an improvement on setup time/portability? How heavy is your 10"? Easily liftable by 1 person? Hopefully upgrading in the new year.