Playing with the Nano Tracker

[Mickoid (Michael)]

Following on from Tony's great shot of the Witch Head nebula, last night I drove out to a site just 20mins from where I live to test out the darkness. It's on the outskirts of Melbourne but there is low population density with very few lights. Melbourne's glow is very evident to the west and illuminates the area to the extent of being able to see where you're going without a torch.

I wanted to see if I could capture the Witch Head from here so I just used a tripod and Nano Tracker for a quick set up. Unfortunately, I had to work the next day and so I could not spend too much time under the clear skies.

I shot these with the 50-200mm Sigma zoom lens @ 200mm f5.6 so I was pushing the boundaries of this little tracker and the payload was rather heavy. It did an alright job though, with 23 x 1 min subs for each object. The Witch Head was shot at 1600iso and the LMC was shot at 800iso, both on the modded Canon 550d using a UVIR cut filter.

Conclusion: A promising site and the Witch was revealed from here so I may return to give it a decent go with better equipment and more exposure.

[Sunfish (Ray)]

Amazing for a 200 5.6 . That nebula is a little dim I think. The tracker is working well.

[Mickoid (Michael)]

Yes Ray, for something that sits in the palm of your hand, they do a great job. The nebula is dim because it will need a lot more than 23 minutes exposure to see it well. At least I know that the sky is dark enough here to reveal this elusive object.

[bojan]

Where is the site?

In the past I used John's Hill lookout, it was OK.

[Mickoid (Michael)]

This site was in Christmas Hills, the only drawback is finding somewhere with public access without so many trees! Gotta love the trees though, we need them and so does the local wildlife. Sugarloaf dam is a good place if you get in there before they shut the gates, it just means there can be a bit of a wait for twighlight to end down here during summer. I don't start shooting until about 10.00 pm, so it usually turns out to be a late night out.

[foc (Ross)]

Hi Mick

Usually only silently appreciate DSO work but your results with the nano tracker on the witches head in a short imaging session are very cool. Hope you get some smoke free nights at your new location.

Ross

[raymo]

Great job Michael.
I was out testing a new lens, and noticed that my acquisition details were very similar to yours ,16x60 sec @f/4.5 [ compared to your f/5.6] ISO 1600, and
yet no sign of the witch. My sky is Bortle 3, do you think that your camera being modded would have anything to do with it?
raymo

[Mickoid (Michael)]

Too many factors to point to any one particular reason Raymo. Could be your lens focal length or contrast, transparency on the night, camera sensor, processing technique etc. I've used an unmodded camera and have been able to capture it. I've read that some actually recommend using an unmodded camera because it is more sensitive to blue which suits this reflection nebula.

I shot these from a bortle 4 sky so your bortle 3 should be better. I do notice that there is no evidence of the nebula in my subs. Did you actually process the stack? You were also two thirds of my exposure so not a direct comparison in integration time but maybe your wider aperture setting makes up for that. All I can suggest with what you have is to stretch the image and increase the contrast considerably just to see if any definition of the nebula is revealed. Good luck!

[raymo]

Cheers Michael, focal length was 85mm. I tried increasing and decreasing
the level of the high, medium, and lowlights. I'll try your suggestions.
thanks raymo

[Paulyman (Paul)]

Great shots. Looks like a promising site for future work.

[LostInSp_ce]

A couple of beauties Mick, you've done well with that setup. Judging by the results I'd say that the new site has passed the test.

[Ant0nio (Tony)]

Two lovely widefields Mick, looking forward to seeing an update with more data, also your previous post of NGC 1365. Congrats on finding a decent dark site too.
Cheers,
Tony