pipnina

How big counts as big? 16" is certainly larger than most people would want to put up with, unless it is going to live on a concrete slab in the garden!

My 10" is about as big as I think I could transport and set up reasonably. Maybe if I was desperate for more size 12" could fit... But the tube alone for the 10" is already 14KG let alone the base. And it takes up nearly the full length of the car boot.

I will say though, the difference in view quality between the 5" newt and the 10" newt I have owned was no comparison. The 10" wins hands down. Outside of maybe exceptionally large objects? But then my 10" captured andromeda very nicely (bortle 4).

21 minutes ago, Paul M said:

I don't expect to see anything like that ever again. It was the third significant display I 've seen in 50 years of looking and by far the best. Many years ago I saw an overhead "corona" for a short while, but nothing like the intensity and sky coverage of 10th/11th.

Of course I could travel to arctic regions to ensure i get another display in my lifetime...  

A large part of the drive for building an allsky camera was to capture aurorae and other special events. In that respect, it's already performed beyond my hopes and expectations! 

Like the song says. "Oh what a night..!"

 

Indeed, I went outside to put the cover back on my scope when i noticed it on friday.

I called for my dad who was inside the house, and for him to tell my brother as well.

Three of us stood in the back garden for about an hour before it tapered off. My dad said he saw hints of it when he lived in and visited Scotland but had never seen it this intense, and certainly not 5 degrees further south than the Scottish border!

I'm fairly sure I won't see it again outside of the ongoing solar event (there has been talk of another ejection, but who knows if it will be visible to us). At least not without intentionally chasing it. Definitely feels like a "once in a lifetime" event.

1 hour ago, Nik271 said:

T Cep is a red giant of colour index B-V = 1.5 so most of its light is in the red part of the spectum. My guess is that its magnitude in R band is way higher than the visual (V) and your astromodified camera is very sensitive in the red. 

1 hour ago, Nik271 said:

PS: just looked it up at AAVSO, in I (near infrared) in August 2022 T Cep has observed magnitude of less than 3.  

I suppose that would make sense then, it still seems a bit odd that it has no halo vs Alfirk's prominent one but the percieved brightness in blue vs R-NIR would explain the core size similarity.

Thanks!

I was wondering why in this older image I took on a full-spectrum Nikon D3200, that T-Cep was so bright.

It is supposed to be at least 2 magnitudes darker than Alfirk even when it's at the peak of its variable phase, but despite how big and bright it looks in the image it has no halo like Alfirk.

Could it be something to do with the camera's full-spectrum mod?

The 80 or 100mm fan included in a mini pc stands no chance of causing vibrations that will affect your images.

If that could be so, anyone with a cooled astrocam would be stuffed!

I'd say choose whatever PC is both small enough and powerful enough to be useful to you and don't worry about the cooling!

Just got back in from my own aurora watching in south devon near Plymouth

Some DSLR shots and it looks stunning!

I never thought in my life there'd be a visible aurora above my house! People spend thousands on week long tours of the arctic and don't see this

If the holes on both parts have a matching PCD (Pitch circle diameter) you should be able to get around this by filing that notch out, I'd suggest on the top hole in your image provided if you go that route.

Unfortunately that's the only option I can think of besides also buying a new curves plate, "teleskop service" offer them in their DIY section I THINK.

I captured this during astro twilight season in 2022 with an 200mm f4 newt and RGB filtered RisingCam571

I only got 3 nights worth, about 3 hours each night centered around true midnight. I feel like it came out quite nicely, however I am about as south as can get in the UK, so someone in scotland is likely to get far less usable time, if any!

This was before blurx/noisex so it's as true a respresentation of the data quality as can be for a processed image I suppose.

8 minutes ago, Elp said:

Can you find a spares camera and replace the mount?

Swap the mount on the adapter for a real camera body's mount? I do have an EF mount camera which is scrap so if they fit it's possible.
I got some email back from the Astromechanics guy saying I may be able to adjust it myself but they give no clue as to the electrical solution...

I have contacted my local London Camera Exchange branch and have arranged to have the lens sent away for mount repair. However even if the lens side is repaired successfully it might still wobble on the adapter as the EF mount camera I have did not wobble but able to rotate due to the worn pin...

I got a 300mm f2.8 lens from eBay, but it turns out the mount has a worn locking pin so it can rotate a bit when my astromechanics adapter is fitted, and the adapter is slightly too thin on the mount face leading to wobble (checked with genuine ef camera, rotation is the lens' fault, wobble is the adapters fault)

I was able to use electrical tape around the flange face to provide enough packing (2 layers) to make it a snug fit with no wobble and resistance to rotation... However upon doing so the adapter no longer makes proper electrical connection with the lens! And it cannot control the aperture or focus. Which is very important as this lens cannot be focused manually.

I'm hoping people here might have a good idea or two for me to try, as I really want to try and make this work, and the image I got from it last night (between clouds) showed it is a very sharp lens wide open at aps-c sensor size despite its age and the tilt introduced by the sloppy mount connection.

Thanks for any ideas!

I've read about Dubai using silver salts to force precipitation and cloud formation. Maybe we can work out how to do the reverse so our island can see the sun & night sky a few times more a year

I think anyone who suspects they suffer from SAD during the winter in the UK needs to look at vitamin D tablets if they don't already.

We need sun exposure to get the vitamin normally, so almost everyone needs it in supplement form and it can affect your mood when you become deficient! It wasn't a life changing difference or immediate for me but I could swear I suffered far less this winter than previously. It's supposed to be good to take for health even if you don't have SAD anyway, and 180 (half a year of) pills are pretty cheap.

As for astro... I know exactly what it's like to become disillusioned. For me it's the blasted weather. Months on end without the ability to get the kit out. A big struggle to get it all set up when the chance arises and, invariably, there will be technical issues! And because of the extremely limited time we get here to observe I feel all my images are left half cooked. I feel many of my images need 4, maybe even 8 nights worth of observations to let me truly get the image as clean as I'd like. But in this wet puddle of a country that is a year's fill of observations!

I have been working to sell my beloved triplet, simply for being both too big and too slow. f5.1 just won't cut it in this place. But telescopes are seldom made faster and the RASA is also very heavy. I am trying out a very nicely sized and fast Canon 300mm f2.8L lens, the 1989 version. I haven't had the chance to test it yet but I have my fingers crossed. In theory once I upgrade to a full frame sensor (either 2400MC or 6200MM - binned x2) it will be *faster* than an APS-C sensor on a RASA8.

I am pulling my hair out trying to juggle my kit and finances during this transition and experimentation but i have my fingers crossed that once I'm done I will have downsized my kit to the point where I can pick it up, plop it down and hit go, and even if I only get 1h of images it (should) have the SNR that my triplet+571 cam would achieve in 6 or even 12 hours!

1 hour ago, Celerondon said:

I see why you are confused because this story is as confusing as that picture. From your account, I can’t understand how the mount did anything after you parked it.  It is also hard to figure out how a GEM in the northern hemisphere tracked itself into the position shown in this picture. 
 

is there any way that someone or something could have slewed your HEQ5 into this unnatural position?  Doesn’t your mount park itself while pointed at the north celestial pole?  A tracking mount should rotate in the other direction and I don’t get why your dec axis isn’t aimed at the pole.   Kids, or cats, perhaps?

 

Don

I do have a mischievous cat however even his powers of destruction haven't affected my telescope yet. No kids to speak of.

I have only assumed so far that the mount or EKOS simply loses track of where the mount should be pointed... But why now after years of it working fine? Perhaps i need to look into mechanical issues as a struggling stepper motor or slippery clutch could maybe cause it to wig out?

52 minutes ago, ONIKKINEN said:

Sorry, dont know anything about EKOS/Indi, but something like this has happened to my EQM-35 and AZ-EQ6 when using NINA. So there is a chance this is a Skywatcher thing and not a software thing.

For me the weird wrong way slewing happened randomly and wouldn't go away within the night it happened. I ruled out different things and was left with only one option, the mount itself being confused by sync commands from NINA creating a bogus pointing model of some sort. At the time i used the USB port on the hand controller as a way to connect the mount to the PC, and a temporary fix was to factory reset the mount through the handset. Most likely not helpful for your case, different mount and control setup and all but thought to mention that a very similar thing happened with my mounts.

I don't know enough about the finder details of the skywatcher mounts under-the-hood operation, do the handsets act as the whole brain while the board inside the mount simply works as a stepper motor controller? If so It could be EKOS making alignment issues. If the brains are inside the mount then maybe I could plug my handset in and give it a factory wipe of some sort?

33 minutes ago, Elp said:

If you've parked and powered down I don't understand how this has happened. Was it off prior?

I always power up my setup pointed at the pole star with the counterweight pointing as close to straight down as possible. Usually the first goto slew will be off by some ten thousand arcseconds or so but the first platesolve will bring it within a few hundred, and by 4-5 platesolves it's normally in the 20 second tolerance I have set in EKOS.

I feel like I should have a security cam pointed at it (for multiple reasons) as I think many issues with controlling it from indoors would be solved if I could see it while controlling it!

Imaging was going well on M101 a few nights ago, but when it crossed the meridian EKOS/Indi or the mount itself had a wobbly performing the flip and it kept pointing in the wrong direction.

I went outside a few times to right it back to home position after hitting park in EKOS. It messed up each time. Eventually i hit park for the final time and gave up.

When I looked at it the next day I saw it like THIS! I had to perform a lot of careful maneuvers to get it out of there between the tripod legs! I have no idea how it managed it or how mount positioning could go so wrong... Could this be something to do with EKOS's alignment settings? I cleared them a few times when it was parked and also let it "sync" in the park position so it knew it was pointed at 88 degrees on DEC etc. It still refused to point properly.

First of all, my condolences! Rest assured you aren't the only one who did something stupid today... I will be making an "oops" post myself tomorrow.

It's possible you could buy a replacement optic from TS themselves, as they have a selection of telescope-building supplies including lenses:

https://www.teleskop-express.de/en/telescope-accessories-5/telescope-diy-improvement-299/telescope-making-optical-parts-91

Maybe there's even a triplet that fits your telescope OTA? Who knows.

For a small sensor I'd agree with the samyang. No direct experience but people's results with it that I've seen have been terrific.

I own a 135mm f3.5 canon FD lens for my AE1-Program. Even wide open it has incredible full frame coverage but just a bit of blue fringing that could probably be taken out with a UV-IR cut filter:

13 hours ago, ollypenrice said:

I discovered this when painting a steel handrail in front of the house. On a hot day it flowed out nicely.

Olly

Might explain why my hammerite application went so badly... It was 5c at the time!

2 hours ago, Peter Drew said:

Give it a good sanding down and then a coat of silver-grey Hammerite.   Available as a spray can     🙂      

I've used hammerite at work, sadly they bought it in paint pots and we were painting onto paint (valve handles needed to show what the valve carried by colour)

Brushing it on wasn't most effective... They looked a bit like a red tar monster when we were done haha.

1 hour ago, Elp said:

The thing with rust which I presume is on it, if it's on the metal it is extremely difficult to get rid of without some sort of real surface grinding and pre treatment, hammerite is supposed to cover the rust and metal but does it continue to rust underneath?

When I painted an area on a previous car, even when sanded down to bare shiny metal, a few coats of primer and a few coats of spray paint and lacquer, it still continued to rust a few months after. I suppose this application it isn't so exposed to the elements.

With paint you usually want a good keyed (textured) surface so there's something and more surface area to adhere to in the absence of an electro static process. Maybe use a coarse grit sandpaper to finish the surface prior to coating. You can always sand down with wet and dry to smooth it off afterward but needs a few coats of paint prior.

Bare mild steel will corrode very rapidly in wet environments. Rust is also supposedly self-perpetuating and a small amount of rust formation will crack or bubble paint allowing more oxygen access to the metal.

I suggest completing rust removal, preferably by wire wheel (you can buy them for home electric drill chucks, flapper wheel may also work). If you want to ensure it's moisture free in the cracks or pits you could always stick the metal in an oven at a skin safe temperature for a few minutes.

I need to think about all this myself, as my HEQ5 is starting to look a bit shabby with some parts of it rusting up and the counterweights losing their paintwork... Eventually it just catches rust and there's nothing you can do about it I guess. I suspect modern cars can avoid rusting on bodywork much more easily since they can control the conditions and state of the bare metal much more easily in the factory before applying multiple layers of rust protection below the paint.

16 hours ago, Clarkey said:

Doesn't sound too bad for the repair. I'm glad it worked out ok as I have a RC imx571 too. (Probably on your recommendation)🤣

Same here. I look in mine and see rust and during operation it sometimes stops and needs to be off-on cycled so I fear repair could be in its future... Or the crashes are purely software based...

3 hours ago, TiffsAndAstro said:

Bit late to the party but I remember making a cost list for a 1st year project 35 years ago at uni and the film and processing cost alone were more than £3k. Was shocked when I was told no chance, lol I am politely paraphrasing my tutor's response

 

 

The film cost was that high!?!? Was Kodak tech pan that dear or are we talking about some sort of scientific glass plate that's hypered, high speed but fine grain, and comes in sizes of 4x5 inches at the smallest and requires cooling and gases to store?

A normal colour roll of 35mm or 120 was quite affordable until only very recently when the costs rocketed up.

1 hour ago, Bugdozer said:

This is one thing that I am always curious about when people talk about really dark skies and the descriptions of them given in the Bortle classifications, because some of it doesn't quite make sense to me. 

Firstly, a higher Bortle sky is always going to have more light from the sky overall than a lower Bortle sky. No objects actually lose brightness under a high Bortle sky, they just lose contrast against the increasingly bright background glow that is everywhere, until at some point they are effectively rendered invisible. But their light IS still coming down. 

However, in my experience, once you get down to about Bortle 2.5, there isn't actually enough light to see any shadows at all. The Milky Way could be right overhead, and clear to look at, but I can't distinguish between looking at the ground and having my eyes shut. Basically, the amount of light given off by things like the Milky Way is below the threshold at which my eyes can detect reflected light from objects. I can believe something like Venus could give off enough light to cast a shadow at its brightest, but if I already can't see the ground at all, then having an even darker sky is not going to make shadows on it more visible. Seeing it reflected off water makes sense, but I am dubious of darker skies seeming to make our eyes more sensitive to light which is already below detection threshold.

The sky at my home has an Exposure Value (EV) of about -5.5 or so, and it's already dark enough that the ground is very hard to see even once I'm adjusted.

However a place near me is much darker, dark enough to see the MW core and even sometimes the outer spirals, which means it's probably closer to EV-7 or even EV-8, I can see the ground at this level but not clearly. I would guess if it were just the MW core in the sky and no sky glow at all, I'd struggle to see any ground at all as you say. The milky way just isn't that bright!

3 hours ago, tomato said:

Got an update from Eddie, the damaged PCB is now with the manufacturer (Touptek) for repair. He told me not to worry but I can't see me getting it back before astro darkness disappears, but then we probably won't get a break in the clouds either, so what's the rush?

It may be different up north where you are, but in devon I can manage about 1.5-2 hours of imaging during the astro dark holiday if weather permits, and with narrowband imaging I can get away with a bit more.

The brightest sky I see from that period here is when the moon is out, which means a moonless night in that time window is still better than normal full moon conditions, under which I'd either image a target at opposite sides of the sky to the moon, or use narrowband, and my results are usually somewhat decent as the last few years the summer period has had a good number of clear nights so I can make one target a multi-night project (relative to UK average...)

13 minutes ago, symmetal said:

I would wait until you see what results you get with your Canon lens with your current camera as far as corner star shapes are concerned before buying a full frame sensor. It wasn't until I bought the RASA 11 that I could take full frame images with the 6200MM with good overall star shapes.

My Canon 'L' 100-400 zoom gave poor star shapes over the whole frame unless I stopped it down to f8 when it was tolerable. A prime lens should be significantly better than a zoom of course, so hope yours performs well.

I tend to software bin my 6200 images after stacking, as the full size images can be a bit slow to process, especially if doing a mosaic.

2x2 software binning gives 2x the noise and 4x the signal, so a 2:1 improvement in S/N. Noise adds by using the square root, so with a read noise of say 2e, the 2x2 binned read noise is sqrt( 4 * (2^2))  = 4e. 🙂

Alan

Wait noise adds with the square root?? How does this work?

I want to improve the speed of my setup. I worked out that if shooting only RGB then the ASI 2400MC would afford me effectively the same resolution image as my RisingCam 571 (6000x4000) but with a wider FOV due to the larger pixels, since I am speeding up my imaging with a normal camera lens I expect that would be best for star shapes anyway, while affording me a 1 stop boost to my speed (so 6.2x faster than my RisingCam+ f5 scope)

However it means narrowband (My main interest turned out to be Halpha only really, not worried about the loss of SII and OIII) becomes much less efficient as only one subpixel gathers data for it.

If I got the ASI 6200MM I can keep my narrowband capacity but with the 3.76 micron pixel size, the same as my RisingCam, I won't gain the speed increase as I would with the 2400MC.

Unless, I binned. A 3200x4800 image might be a little small for me but could be servicable. However this increases the effective read noise by a factor of four even though in theory is gives me a 2 stop light sampling boost right? So am I worse off with the 6200MM and should stick to RGB imaging with the 2400MC if I want speed, and simply forgoe narrowband for now?

Interested to hear thoughts.

Thanks