Lurker for many - now my first decent widefield

[sacredblack]

Hi all,

As the subject says I've been a lurker for several years and managed to escape daily life for a few days last week and went up north a little to Orroroo (SA).

I spent time re-learning drift alignment and working out some short cuts.

I managed only one nights worth of shots before the weather changed for the worse.

But at least I managed a few shots. Here are a couple.

Here's the tech details.

Canon 5Dmk2 (unmoded), Canon 50mm f1.8 set to f4, 1600ASA with internal normal noise reduction, 180 second exposure, Meade LXD75 mount.

I've been using "The Backyard Astronomers Guide" by Dickenson and Dyer as a bible for my experiments.

Things learnt: my 50mm lens (real cheapie $140) is only good at f4 and up. Still the edge (on a full frame camera) is heavily abberated but fine on my 450D.

Dickenson and Dyer suggest trying the camera's internal noise reduction over dark frames but the catch here is that the noise reduction does not affect the RAW images taken but only the JPEG ones.

I've got a cheap Orion scope (guide scope sold by Bintel) on the Meade mount which really needs to have a diagonal added to it. I had really sore legs the following day.

It was great fun and wonderful to get some shots that I could actually print posters from.

Steve R.

PS - next step - mmmm the Canon 60Da looks nice....

[MrB]

Nice work Steve, and welcome back! :)
Were you manually guiding? Probably not needed at 50mm ;)

[sacredblack]

Thanks MrB

No manual guiding as I was trying my hardest to get the drift alignment happening to see the mounts limits. My plan for the following night(s) was to load up my 450D with a 55-250 lens and do some experiments to see the mounts guiding limits. Also to do some longer exposures, darks and multiple exposures as well. Ahh next time....

I have been eyeing off the Skywatcher Synguider, self contained autoguider as a possible future addition.

Steve R.

[jjjnettie]

It's a sweet little lens for the price. :) Affectionately known as the Nifty Fifty.
You definitely have to knock the f stop up a few notches to get it working at it's best don't you. Once you know where the imperfections of the lens are (Mine is on the top left) you can frame to suit.
They're excellent wide fields. You should try it on the LMC next, it fits the FOV perfectly.

[RickS]

Nice shots, Steve!

[CapturingTheNight]

Great work Steve. :thumbsup: The ol' nifty fifty is probably my second favorite lens to use piggybacked after the Tamron 90mm macro. Love the star colour you got in the southern cross one. If you can fix that red/magenta amp glow around the fringes and darken those dark nebulas a bit by playing around with the levels you will have a cracker.
Cheers
Greg

[naskies]

Nice work, Steve! You have some nice colours in these shots.

You may find that virtually all camera lenses need to be stopped down to f/4 or smaller to become "good" (especially on full frame sensors). Even high end Canon lenses like the 14 mm f/2.8L and 85 mm f/1.2L are quite horrible at fast apertures - they need f/8 and f/4 (respectively) to have sharp corners.

[sacredblack]

Thanks for kind comments guys !

obsidianphotos you mention the " If you can fix that red/magenta amp glow around the fringes..". I'm presuming you mean at th edges of the frame not the stars. I'm not sure where that's come from. I did a little adjustment and those colours appeared as I cranked up the Saturation. Any suggestions to fix this issue ?

Ahh yes the LMC. I was eyeing that off on this trip but it was unfortunately just above the house we were staying in. Also the fire was burning away in the house putting out smoke in that area. In fact an earlier Southern Cross shot has this "lovely" smoke streak through it where the lights from the town and smoke hit.

Thanks again for the encouragement. We have another trip away in November where I might throw the LXD75 10"SN on and see if I can't manage a nice shot of Orion as well.

Steve R.

[CapturingTheNight]

Yes, sorry Steve, I did mean around the edges of the frame. To me it looks like amp glow, which is when the sensor heats up to much during a long exposure and "leaks" into the image. Next time I would try and let the camera cool down longer between exposures and I would also try doing separate dark frames at the end of the night and not use in camera noise reduction. To try and remove it from this image I would use the selective colour tool in Photoshop to pull down the magenta slider in both the red and magenta channels. The image would probably look fairly green so I would also then either have a play with the green channel or just use the free "Hasta La Vista Green" Photoshop filter plugin to remove the green. I would have also duplicated the image before I started playing with it, so that I could mask back in those magenta nebula regions that would be effected by the above actions.
What image editing software do you have access to? If you would like, with your permission, i could have a play with this image and detail the steps I took. I'm by no means an image editing expert but I'm happy to help if I can.
Cheers
Greg

[markuslebt]

nice colors, nice clusters, nice dark nebulae, nice spectral color of stars. very good first shot.DSLR is king. somebody send me his old EOS for a hamburger..hehe