Further Adventures at 50mm

[Knight of Clear Skies]

Here's a selection of images taken with my 50mm lens on Sunday and Monday night, hope you like them. All shot at f4.5 and ISO 800 on either the observatory's modded 100D or my 1100D. Took 30 dark bias for each but no darks or flats.

Orion - 22x210 second subs, 77 minutes in total.

California Nebula and the Pleiades - 12x210 second subs, 42 minutes total.

Cepheus and Lacerta - 15x180 second subs, 45 minutes total.

Andromeda & Triangulum - 17x210 second subs, 59 minutes total.

Think these were all taken on my EQ3-2, I tried to use it for the wider shots while using a more sturdy Vixen mount for the longer lenses, but it all got a bit crazy with all the swapping of cameras when batteries ran out and lenses when they misted up. Taken at Caradon Observatory, Cornwall.

Would welcome any feedback, especially constructive criticism. These are all work in progress images, I have StarTools on my laptop here but can't get PS to install for some reason. I know there is more nebulosity hiding in there because I could see it in my high-ISO framing subs, now I have some better data I'm going to have to take a more serious look at processing tutorials.

[tingting44]

wow what a stunning set! i hardly recognized the constellation orion 

i really must try my nifty 50 on my HEQ5 with no scope

[wxsatuser]

Great set.

Orion has come out very well.

[uhb1966]

Great - and with a "small" mount! Congratulations!

(I cannot criticize - i think these are just great photographs!)

[Adamar98]

They're great images. Orion is my favourite. I must have a crack at it with the 50mm. Brilliant work.

[RichM63]

I've had nothing but solid cloud and rain since buying the 50, not even taken a snap with it.

I can't offer constructive criticism about the images, they are great (maybe shot 1 is a bit too red overall?), but the fact that you are using a bog standard EQ3-2 and fairly low end photography gear is inspiring to the likes of myself.

My EQ3-2 is sitting right in front of me, with ball head attached and all motored up ready to go, I now have thick fog, and so I have shown your images to the mount in the hope that it will cheer up a bit in anticipation of good things to come.

[Alien 13]

It is good to see another imager getting good results out of the EQ3-2 with Camera and lenses, that is very nice set and Andromeda looks very cool when shot in widefield I realy like the Pleiades shot too (and Orion).

Not meant as a criticism but have you considered making an aperature mask to remove the diffraction spikes (although I am not sure if it would be as effective as the internal blades).

Alan

[robbie c]

Cracking images Knight well done keep up the good work 

[Nathan_Pembs]

Some great images there, esp Orion plenty of HA going on there.

You also got the Witches Head nebula bottom right corner (appears upside down), that's a faint target!

[leemanley]

You must be more than pleased with this set, I know I would be ! Love the wide M31 & 33,do you know the name of the star that seperates the two ?, but really loving the Orion image, it's nice to see the individual components that make up this great constellation, need to get my fifty out after seeing these !

Cheers, Lee

[Knight of Clear Skies]

Thanks everyone. I'm really pleased with these, especially the Orion shot - I feel it's a real step forward for me.

I can't offer constructive criticism about the images, they are great (maybe shot 1 is a bit too red overall?), but the fact that you are using a bog standard EQ3-2 and fairly low end photography gear is inspiring to the likes of myself.

My EQ3-2 is sitting right in front of me, with ball head attached and all motored up ready to go, I now have thick fog, and so I have shown your images to the mount in the hope that it will cheer up a bit in anticipation of good things to come.

Yes, I think the colour balance may be a bit off in all the images. Normally I'd run HLVG to reduce any green but I don't have it here, so had to resort to some random curve stretching instead.

Hope you get up and running soon with the 50mm, they are great fun.

It is good to see another imager getting good results out of the EQ3-2 with Camera and lenses, that is very nice set and Andromeda looks very cool when shot in widefield I realy like the Pleiades shot too (and Orion).

Not meant as a criticism but have you considered making an aperature mask to remove the diffraction spikes (although I am not sure if it would be as effective as the internal blades).

Alan

Yes, you don't need a lot of kit to get some decent results. My mount seems to be behaving a bit better now I'm balancing it more carefully, it's fine at 135mm and I think I'm right in saying you've got good results with yours at 300mm?

Yes, an aperture mask might give better stars on some of these images - I prefer the six or eight pointed ones to what the five bladed Canon lens to them.

You must be more than pleased with this set, I know I would be ! Love the wide M31 & 33,do you know the name of the star that seperates the two ?, but really loving the Orion image, it's nice to see the individual components that make up this great constellation, need to get my fifty out after seeing these !

The star in the middle is Mirach, a red giant in Andromeda. There is a galaxy very close to it which is very difficult to observe as a result, known as Mirach's Ghost.

[RichM63]

Whether it was just dumb luck on my part, balancing for the 700D + 300mm Sigma was acheived by removing the larger lower weight and moving the smaller about 5mm inboard from it's normal position. This balance is way better than when I stick the 150/750 OTA onto the mount.

Itching to try the 50, it could be soon, my crudy weather is moving North, sadly for you, that means Cornwall. Sorry about that. Although I did get out for an hour this afternoon to get some shots of a wrecked ancient fishing vessel.

When processing these types of image, what technique do you employ to help decide whether it is a Star Field or Noise as you try to pull out detail?

[Pete Presland]

excellent set of images! the Orion is particularly good, with Benards loop, flame and horsehead all showing very well. also very nice to see a widefield with the Andromeda & Triangulum galaxies in it.

[Knight of Clear Skies]

When processing these types of image, what technique do you employ to help decide whether it is a Star Field or Noise as you try to pull out detail?

I'm not the best person to ask but there are a couple things I'm aware of. Overstretched data tends to appear spiky in the histogram. Also, when looking at 100% chrominance noise is easy to spot, there aren't many green objects up there.

Hope the weather clears for you soon.

[ollypenrice]

These are a roaring success. I've seen this very combination in action here in other hands and it really does work. This data is well worth some extended processing so here are my thoughts;

Orion needs gradient removal. The best method is DBE in Pixinsight. This would allow you to stretch a little harder but, remarkably, you have the Witchead showing nicely already. Also, if you used layers and made a softer stretch for the bright cores, you'd find you could blend them easily.

California to M45, really nice. Again there's a slight gradient top left to lower right which DBE would nail.

Cepheus and Lacerta; personally I'd warm up the colour balance a bit. I think green de-noising either wih Rogelio's help or in PI would make a difference and then I'd ease up the reds very slightly.

Wherever you have Ha signal in RGB there is a dead simple way to make it pop. Photoshop, Image, Adjustments, Selective Colour, Reds. Take the top slider in reds to the left to lower the cyans in red and you'll get a real boost.

Another good reds trick is to make two copy layers, set the top layer to Blend Mode Soft Light, flatten that on the second layer, set the second layer to Blend Mode Colour, put in a light Gaussian blur (0.5 ish) and flatten.

I can't exaggerate the prowess of DBE and SCNR green in Pixinsight on this kind of broad target.

Noise; never denoise the whole image. I usually make a copy layer, run a noise reduction on it then go to the top layer, use the colour select tool to pick out the faint and noisy bits, slightly expand and feather the selection, then run the eraser over it at about 30%. How does it look? Run the eraser over it again, etc. This avoids blurring your sharp bright stuff with the noise reduction.

You obviously had a cracking night of it!

Olly

[Knight of Clear Skies]

That's brilliant thanks, I can understand most of that and it helps confirm some of my suspicions about the remaining gradients and colour balance. When I get home I can run HLVG on them and will be working on a better monitor. I'll also try and get some more data further down the line, I think I should be targetting 30 subs? 

[ollypenrice]

That's brilliant thanks, I can understand most of that and it helps confirm some of my suspicions about the remaining gradients and colour balance. When I get home I can run HLVG on them and will be working on a better monitor. I'll also try and get some more data further down the line, I think I should be targetting 30 subs? 

30 sounds good. Can you dither or make a very small mount movement a few times during that set?

Olly

[Earl]

this makes me want to get my QHY8 and Canon 200mm F2.8 into action. all in good time

[laser_jock99]

....... remarkably, you have the Witchead showing nicely already.

 

Olly

First thing I noticed as well. You must have a reasonably LP free site!

[bogdog]

nice images

[Knight of Clear Skies]

30 sounds good. Can you dither or make a very small mount movement a few times during that set?

Olly

I think my EQ3-2 will take care of that for me , even at 50mm I can see a little drift between frames in DSS. You can see the periodic error in this Comet Jacques animation I made:

That's a crop of 135mm subs, I guess that would be sufficient for dithering? I've set up the polar scope more carefully since then so my alignment should be better now.

First thing I noticed as well. You must have a reasonably LP free site!

It's very dark at Caradon Observatory, best reading that night was 21.28 SQM. The nearest streetlights are two and a half miles away in Pensilva. There is some LP low down to the south-east, where the lower left hand corner of Orion was sitting but the Witch's Head was far enough around to avoid it. I tried to remove the gradient using StarTools but looking on this monitor I can see I didn't get all of it. I suspect I was catching the light dome from Plymouth, which is just under 15 miles away in a straight line.

It's dark enough that you can see the Milky Way immediately after leaving a well lit room. I think I could see Triangulum, although I'd want to confirm that. It's a lovely site but unfortunately I live 275 miles away. I'm hoping to arrange things so I can spend more time down there next year. In the meantime I can get some worthwhile practise in up here in Hertfordshire - even without an LP filter I can get some decent results up here, just not so quickly or easily.

[Alien 13]

Hi Knight,

I was wondering if you had removed the locking screw from the RA setting circle, the mechanism causes quite a bit of uneven drag to the RA axis and it it is much better without it. The removal also allows balance to be set more accurately.

On my mount the inner circle now rotates with the axis and provides a convinient way of setting polar alignment using the hour marks on the dial with refrence to the hour angle shown with stellarium.

Alan

[Knight of Clear Skies]

I was wondering if you had removed the locking screw from the RA setting circle, the mechanism causes quite a bit of uneven drag to the RA axis and it it is much better without it. The removal also allows balance to be set more accurately.

Great tip thanks, I will give this a go.

[Beulah]

These images are astounding!

You have got there before me, as we were discussing the similarity of our gear sometime back. Did you end up stripping re-greasing the EQ3-2 or adding any other mods to it? I've done the re-grease - just waiting for the funds to build up for the polar scope...

[jabeoo1]

Superb!  I was glad to be sat down when I opened the thread to be honest. Huge wide field vistas are so valuable to both astro photography & visual astronomy.  Beautiful in every respect.