Stub Mandrel

We ain't pushing them, we're trying to find them

You've got the colour difference between the two nebulas nicely.

Yes that's what you sent, looks right here >PHEW<

I'm fairly unusual in having only bought one thing of @DRT - it was an EQ5 tripod to replace the standard EQ3 one. You can much improve the EQ3 by clamps at the top of the sliding sections (and keeping it as low as possible) but the EQ5 does make life easier.

Grrr :-(

This lovely widefield photo by Bob King on the Sky and Telescope website:

Nige is getting some serious mojo

I 3D printed this quick and dirty finder for widefield AP:

What a Monster!

I forgot the smiley I think there's just a hint of the Horsey in there. Please repeat the exercise in two weeks time!

I'm not sure, but there looks to be a bit of a gradient?

Yes, but be aware that a long journey to an 'orion class site' might prove disappointing.

My 135mm lens is f3.5 and some are f2, I think, your scope is f5 which will be some of the difference. To be fair, I think the 135mm images look like they have been processed more aggressively too.

Welcome to the Dark Side :-)

I put the marked up one through gradient exterminator, nothing else...

>ouch<

The 'index' shot shows there is plenty more detail in your to image to bring out! 'Gradient exterminator' in Photoshop and perhaps Noel's light pollution action would get rid of the patch in the middle. I think you can find more colour too. Astro pictures are the 'images that keep on giving' :-)

Thanks, that looks like it. I've never come across a program that doesn't load the whole image before!

Weird! I'm opening a RAW in Irfan View and saving as a Jpeg, then using another program to measure the distance. But when Irfan view loads the image it's downsampling it to rather more than half the original dimensions! I've used RawTherapee instead and the distance is now 3688 pixels not 1971! That gives me a focal length of 588mm (using my formula) which is so close to 585 millimetres, well it's basically 0.5%. I wonder what's up with Irfan view?

Numbers! 1 - shoot RAW not Jpeg 2 - Put lots of 'lights' (RAW images of your target, also known as 'subs') into DSS, all the same ISO and exposure. 3 - add darks, bias and flat frames (not essential but they improve the result) and run DSS 4 - the end result averages out all the images and has less noise but greater bit depth so you can stretch it to bring out the detail. See this link for an explanation of darks, lights and the DSS process: http://deepskystacker.free.fr/english/index.html Try 'user manual' 'FAQs' and the tutorials to get started.

I tried a calculation that failed. Can you check my logic? In one of my RAWs Tejat and Propus are 1971 pixels apart and my camera is 5.19um per pixel, so that's 10.229mm distance on the sensor I estimated the angular separation of the stars at 1.9 degrees using Stellarium. I worked out Focal length = (distance between two star images/2) / tangent(angle between the two stars/2) This gives me an answer of just over 300, when it should be 585 ( I have a 0.9x coma corrector). Can you tell me where I'm going wrong?

I got asked for a pictures of my mount, here's a few of the mount. I don't seem to have one of it with the 150PL attached! Also pics of the GOTO box

I've made my own goto box with steppers and home-made gearboxes.

With a polarscope, I have had 2-minute unguided exposures using a 1200mm scope on my EQ3. Google 'drift alignment' if you want the best way of aligning without a polarscope. Neil

Keeping it all in one thread makes it easier to delete everything when the images get too good