Carina Wide Field

Designation (lower left): Eta Carinae Nebula, Caldwell 92, NGC 3372.
Designation (upper right): Open cluster Caldwell 91, NGC 3532, Wishing Well Cluster.
Constellation: Carina
Date: 2020-04-14.
Exposure: 104 x 29 sec = 50 minutes.
Field of View: 7.34° x 4.88°

The last couple of nights outside with my telescope were used in an experimental attempt to capture a very wide field view of the Eta Carinae Nebula and surrounds.

The concept was to remove the guide-scope (see the page header image above) from its dovetail bar on the main scope and in its place mount a Tamron 70-200mm f/2.8 lens (normally used on my Canon EOS 60D DSLR camera).

The lens was then coupled with my main ZWO astronomical camera and used to live-stack wide-field images using SharpCap software.

The role of the main telescope was to be temporarily converted into a guide-scope by replacing the main camera with the guide camera. I was unsure how well this would function.

Imaging with an EOS lens coupled with a ZWO camera whilst using the Skywatcher Esprit 120 as a guide scope.
Main telescope (white, left) being used as a guide-scope for Tamron 70-200mm EOS lens (right, black with blue stripe) coupled (using EOS-T2 adapter) with ZWO ASI071 astro-camera (red). The masking tape was used to reduce the risk of the focus ring and the zoom ring from slipping.

Night 1 did not go too well. I didn’t realise that the Canon lens f-stop was set to f/5.6 when I took it off the DSLR (and SharpCap cannot not control this feature).

I had not taken the lens cap off the main telescope (acting as a guide-scope). 🤨

Focusing was difficult. Moonlight was disastrous. The sky was light polluted suburban. Nebulosity was faint. Images were poor.

Aaarrrghh!!

Night 2 went slightly better. Prior to starting I used the DSLR to reset the lens focal ratio to f/2.8, allowing more light exposure. Despite my concern, the main telescope functioned properly as a guide-scope.

Focusing the lens was still difficult (because the manual focus adjustment ring on a camera lens is very coarse) but at least the Moon was absent this time.

Capture of nebulosity was improved and the image became a bit more more presentable, although vignetting is obvious and the overall quality left a lot to be desired.

So I got my wide field image but the overall lack of quality that I achieved is unlikely to induce me to pursue this methodology very much in future, although it might have its uses.


Follow this link to see my image with Astrometry.net annotated overlay.

Also in the image are: NGC 3519, NGC 3572, NGC 3496, NGC 3503, NGC 3255, NGC 3324 and IC 2599.


I hope my readers are coping with the current pandemic threat, wherever you are. I hope you get to see a bit of the outside world and maybe even the night sky from time to time.

Here in Australia we are basically only allowed to leave home for essential shopping, medical care, work or one hour of exercise. No-one is allowed to undertake non-essential travel and the police make their own decisions about what is (and is not) essential travel during the current covid-19 restrictions.

So, if I left my home with my telescope gear in the back and drove to an observing site, any law enforcement officer who spotted me driving or observing would – not just could – would hand me an on-the-spot $1,000 fine notice. Astronomy is not a good enough excuse to test the police in Oz.

So it was with considerable surprise that I read one of my regular bloggers in the US this week, who wrote about travelling to Amboy Crater in the Mojave National Preserve to take some images of Comet C/2019 Y4 (ATLAS). Even more surprising was that he met an unspecified number of campers there.

I’m not criticising the blogger or the campers, just expressing my surprise that such activities appear to be allowed in the US during a pandemic, especially as it is affecting America much more than Australia at the moment.

By the way, the images this blogger took of the above-mentioned comet are superb! Well worth a look on his Orion Bear Astronomy WordPress site.

Telescope Details
SkyWatcher Esprit 120 mm apochromatic 3-element refractor
(TEMP. GUIDESCOPE).
840 mm focal length @ f/7 with field flattener
(TEMP. GUIDESCOPE).
SkyWatcher EQ6-R Pro mount.
Camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx)
(ON EOS DSLR LENS).
Tamron 70-200mm f/2.8 DSLR EOS lens
(ON ASI071 CAMERA).
ZWO ASI120 guide camera, using PHD2 software
(ON TEMP GUIDE SCOPE).
2018-03-10 Telescope & Roger
Images © Roger Powell
I’m one of the founding members of Macarthur Astronomical Society,
Australia. 🙃

16 Comments

  1. Interesting rig . . . and the results are not all that bad to my eyes, but then I don’t do this for a hobby (and people tell me all the time they like some of the photos I think are just so-so).

    As for travel and congregation . . . it’s very difficult keeping Americans from assuming they are special and excluded from rules and common sense. And I say that with affection, and it’s a trait probably found in people from all over.

    Everyone always rationalizes their needs as “essential”.

    Take care.

    Liked by 2 people

    1. I wonder if that “trait” might not be the best idea in the current circumstances but thanks for your comment. I was curious about folks over there who are still going out while others are in lock down. It just seems to me either the US guidelines are not as strict as ours are at the moment or a lot of people are not taking those rules as seriously as they might.

      I’m old, I’m vulnerable and I’m staying at home until this is over. Plus I don’t want a $1000 fine!

      Best regards,

      Roger

      Like

    2. Guidelines here are dictated by each state and enforced locally . . . meaning, a patchwork of regulations. I don’t know of a good way to force everyone to do anything, even when for their own good.

      Liked by 1 person

  2. Hi,
    Lucky Australians! You get Eta Carinae! How is the visual appearance compared to what you got with the camera’s longer exposure time?
    Cool use of your setup in ways the makers might not have dreamed of. Way above my abilities with a Canon XS and an 200mm dob. But I’m really happy with being able to plop down my 43 pound dob, quick align and observe.
    Here just north of New York City, there are so many cars out it would be impossible to check all the drivers to see if there trips are essential. But rush hour traffic is way down, showing how most people aren’t going anywhere.
    As far as observing, I’ve been staying in my street-light lit front yard. We’re getting a great show from Venus and the (low) morning planets.
    I don’t think people are having a problem with observing in our county parks. I’ll have to check. If people keep a good distance and don’t share views, I think it should be ok. (I’m thinking 4 meters or more separation, for long periods of time in the same observing lot. ) I’ll check with our club members.

    Liked by 1 person

    1. Thanks for your comment.

      It’s difficult to answer your question because it has been so long since I used an eyepiece!

      The Eta Carina Nebula covers a much larger area than M42 and is more even in brightness. So with M42 you will always be able to see the condensed brightness around the Trapezium.
      Eta Carina is a bit brighter around the Homunculus region but not quite so much. But a small telescope would reveal a lot.

      I observe in my street-light lit front yard too. It’s a nuisance but when you only have one option…..

      Liked by 1 person

  3. Thank you for your comments regarding social distancing violations. It is beyond my comprehension that anyone would consider themselves immune to coronovirus. It is arrogance beyond belief !!! I guess some folks just have to learn the hard way.
    I am so lucky because I live in a tiny apartment on the 2nd floor with a huge deck 16 ft.x 30 ft.
    ( light pollution not withstanding) I appreciate your photos and comments more than ever.
    Fran

    Liked by 1 person

    1. Thanks, Fran. I don’t know what the rules are in the US or how strictly they are being enforced. So the instance I read about made me curious. Our rules are to stay at home unless it it is essential to go out for groceries, health, education or exercise and they are being enforced and mostly obeyed.

      How nice to have a large deck to enjoy some fresh air. Whatever your view is like, I think it’s vital to keep an outward looking aspect at a time like this.

      Like

  4. Thanks for sharing your efforts with the different setup. Good of you for trying.

    As for the US COVID behaviors, the ‘leadership’ is a shambles. DT is a spotlight whore who should get out of the way and let people who know be in charge. His example and behavior is harmful and only gains him support among his base of supporters. The more bizarre he behaves, the more they like it.

    Our state is one of only 6 I think that hasn’t set strong restrictions on movement and gatherings. She is pandering to the party officials who are members of the DT band. The county where I live is a liberal/progressive enclave. We are doing things right as far as I can tell. The population is smart and knows better than to risk exposure. The more rural counties are beginning to see the virus make inroads to nursing homes, prisons, and a bad one in a meat processing plant.

    I am now off my stump. Keep the nice images coming. I had a nice view this morning of the Moon, Mars, Saturn, and Jupiter in alignment.

    Liked by 1 person

    1. What happened here is that our Prime Minister (Federal) and Premiers (six states, two territories) meet – amicably – by video conference every few days to share information and develop joint health and economic strategies to manage. They are not all in the same political party but have worked harmoniously, not only together but also with health, border and law enforcement authorities. Opposition Leaders have also mostly dropped the politics and supported the actions taken.

      I never thought it could happen.

      The objectives and restriction rules have been clearly communicated to the public right across Australia and we all know exactly what we must do to beat this pandemic. There are very few calls of dissent. Apart from the daily gaggle of media conferences in front of the flags, grandstanding has been minimised and I think we have been told the truth, with some exceptions.

      I don’t want to say too much about what other governments are doing but it is patently clear to objective observers anywhere in the world that the White House is a complete mess. Poor decision making and the blame game has sadly threatened the well-being of US citizens, whom we regard highly in Australia as our friends. I find that distressing.

      I like your picture of Venus, clearly indicating the phase. I am due to make a similar attempt soon.

      Liked by 1 person

      1. A mess indeed. Thank you for your concern. I wish we would move past the politicking and work together. It would be such a breath of fresh air.

        I look forward to your Venus images through better optics than mine.

        Liked by 1 person

  5. Thanks for the mention and linking to my site!

    To clarify why I went out,
    The Observatory opened up paid astrophotography opportunities and had been asking for more images of C/2019 Y4. I picked the only night available to go in between rain storms.

    I was surprised to see that many people visiting Amboy Crater, but I went there thinking nobody would be around – had the entire place to myself the previous visit. Those I did talk to were pretty much saying “we needed a night out during the craziness and we thought this was away enough from everything.”

    As for restrictions, you gotta realize that California alone has millions of more people than all of Australia. Griffith Observatory, and pretty much all of Los Angeles is on shutdown, but there is no way they can stop everyone from getting on the highways and going where they want/need to go – at least not the way the restrictions are now. I don’t speak for the defiant arrogant people in California, as other than my trips for astrophotography work, I’ve been staying home and following the rules.

    Like

    1. Thanks, Anthony. I would have asked you about this directly but the comments on that particular page seemed to be unavailable to me when I tried. It peeked my interest but of course each country devises its own methods of dealing with the crisis.

      I thought your comet images were worth sharing.

      When I see the daily updates and look at the US figures for infections and deaths I feel like weeping.

      Here in Oz, we have been told to stay at home except for essential work, medical reasons and groceries – and mostly the people are complying. There are some exceptions.

      I hope you stay safe and keep taking those wonderful images.

      Liked by 1 person

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