Stub Mandrel

Hi @DorsetBlue You've got some nice data there, I took the liberty of stretching your M51. Just increased the gamma and then raised the black point, more sophisticated tweaks should work wonders! <edit> after reading Ken's comment I slightly shifter the colour balance away from yellow

I just switch to AM mode for the flats.

That's not minute, it's bloomin' enormous!

Looks suspiciously "similar " to my slightly battlescarred Skwatcher one... Time to clean that filter...

I have a Skywatcher CC, the only time I have had issues with bright star reflections so far was with Alnitak in frame, where I got a blue patch diametrically opposite the star. It was fairly easy to remove (being in a relatively dark and empty bit of sky), so although it is a real effect, it isn't an overwhelming problem as few DSOs share a 130P-DS field of view with a star as bright as Alnitak (mag. 2). As far as smaller stars are concerned I haven't noticed issues with CA or bloating, although i'm nor exactly at the cutting edge! YMMV

The Evostar 90 on EQ3-2 seems to come with a steel tripod

I do have a steel tripod, but I image most of the time. With Jupiter on a computer screen at 2400mm focal length with x2 barlow it sits nice and steady on the screen (if the seeing is ok!) I can't say that I've found vibration an issue when using it visually though. It was poor with the original, unmodified tripod. That said I have never used a bigger scope or heavier tripod, only punier ones so perhaps I'm more tolerant?

I'd agree, my 150PL is a 1200mm Newtonian weighs 5.9 kilos and is quite happy on my EQ3-2.

Here's my latest scope. A virtual pint to anyone who can ID it

Pardon me for butting in, it sounds like you are tightening the screws right up. You should use the two screw adjusters to move the scope to the right place, while the third, sprung, support stops it from flopping about.

Cripes, I image Jupiter at 30fps!

http://adsabs.harvard.edu/full/2011JRASC.105...34M

I had to stack 50 subs of that website and do a stretch before I could read it...!

I find that the 'Noels Action' works, but can also increases teh saturation so there's a limit to how many times you can run it.

What I do is duplicate my stacks and process one for lumininosity and one for RGB. This means you can mess with the colour of the luminosity one to get the best detail, sometimes boosting just the red to give 'fake Ha' helps bring out a nebula for example. I usually blur the RGB one, as this gets rid of noise and makes the colours more even, but also can help spread the colours into the centre of stars, but it struggles for big stars After my 100ISO experience I'm considering taking some shorter subs just to capture the star colours, and use this as an extra layer though.

Still a good catch!

I can spot over-exposed pictures of tennis balls a mile off!

Owl Nebula and Surfboard Nebula from last night using the 130P-DS, tricky one up near the zenith so after seeing that about half the 120s subs were spoiled I went to 60s ones, in the end I was able to stack 1 hr 38 minutes out of just over two hours data. If it's clear tonight I might use the 135mm lens on the Virgo Cluster.

I downloaded APlab yesterday. I analysed a couple of 2-minute images at iso800 taken in single-figure ambient temperatures. It worked out that my read noise (bias frames) was five times that from my darks. That means the Bias frames are more important that darks up to 10 minutes of exposure at such temperatures. That probably explains a lot! I've also found that LOTS of darks (50-100) appear to make make more difference to noise levels than exact temperature matching.

That's the way to do it! Better results than I was getting with low numbers of subs, but I have more LP. Get your polar alignment spot on, go up to a minute and buy an intervalometer off eBay for about a tenner - then you can go in and drink tea/read SGL etc.* while it takes a hour or two's subs! *I know you are supposed to be standing next to the scope with your bins or something....

A good start @StormAurora! How long are you exposing for? If you shoot RAW and stack (plenty of advice on doing this here) you will soon start pulling out loads more detail.

Those who read the depths of the DSS documentation will find that DSS keeps a record of all the frames it uses for a stack, and looks to see if the matching master TIFFs for the provided control frames already exist, and if they do it will use them instead of rebuilding them.

This diagram off the DSS ssite may help understand how the different frames are used. From: http://deepskystacker.free.fr/english/index.html Click the tab 'how to create better images'

Not as expensive as I expected, but will have to queue behind things like Ha filter, guide camera and food... Yep, I gave up of calibrating, because the sun is bright even with the blind down. I think I'll wait until the evening as most of my processing is evening or dull days!

I often see my images and think they are over-processed and noisy. When I upload to SGL, I often go away and come back, and they look bad. I have come to realise that one reason is when sitting down for a long time I relax (slump!) and see the monitor from a lower angle, effectively lowering the gamma of my screen so I end up stretching the dark parts of the image too far. It doesn't help that the back foot of stand slips off the back of my desk, causing it to tilt by about five degrees, enough to make a significant difference! I also find that different programs seem to use different gamma settings, Astra Image definitely displays images with a higher gamma than Photoshop (so I tend to overdo noise reduction and get NR artefacts!) and firefox appears to use higher gamma as well (although the new SGL software seems to be kinder to my pictures than the old system). I spent ages calibrating my monitor, and am soon to re-do it but after changing the angle so I look at it more face-on. I will do this using the built in calibration routine in windows, but are there any other tools for this that are better suited to AP?