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Old 23-09-2018, 05:18 PM
RyanJones
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Tarantula nebula

Tried to pick something far enough away from the moon.

Not overly happy with the result to be honest. The core is so bright, I think this is going to one of those targets I need multiple ISOs on. The overall image was good out of DSS but it was really hard to balance the processing and I've ruined the sharpness a little.

461 x 22 sec
Canon 5d
Celestron C5
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Old 23-09-2018, 05:43 PM
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Hi Ryan
Dont be to critical of your efforts you are doing really very well.
Do you have a focuser mask yet as I think your focus could be sharper may be.
Also with your long fl maybe you need even more subs.
Anyways given your long fl you are doing great.
Grab another five hundred☺
Alex
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Old 23-09-2018, 05:56 PM
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Quote:
Originally Posted by xelasnave View Post
Hi Ryan
Dont be to critical of your efforts you are doing really very well.
Do you have a focuser mask yet as I think your focus could be sharper may be.
Also with your long fl maybe you need even more subs.
Anyways given your long fl you are doing great.
Grab another five hundred☺
Alex
Thank you Alex.
I have had a focus mask most of the way along. With this particular shot, the fuzzyness is coming from my processing. With an extra 500 shots though, I won't need to do what I did to it so I agree that will help 2 fold. I used to think taking more than 100 shots was a lot, now I don't even go outside if I can't see myself getting more than 500 lol. I'm having fun though.

I have saved a focus shot, I'll send it to myself and post it just in case I'm doing it wrong, as it often gets questioned
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Old 24-09-2018, 11:17 PM
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This is a sample of my focus shots.

Am I doing right?
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Old 24-09-2018, 11:55 PM
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Almost nearly the same but I think the angles are not perfectly equal☺.try sharp cap focuser assist and it may say similar.
Alex
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Old 25-09-2018, 12:15 AM
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Almost nearly the same but I think the angles are not perfectly equal☺.try sharp cap focuser assist and it may say similar.
Alex
I’ve seen sharp cap mentioned on here a bit. I was under the impression it was part of a laptop based image capture program... ???
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Old 25-09-2018, 12:18 AM
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Yes but it has a focuser assist but I dont know if it would manage your camera...not saying it wont I just dont know.
Alex
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Old 25-09-2018, 12:30 AM
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Yes but it has a focuser assist but I dont know if it would manage your camera...not saying it wont I just dont know.
Alex
I don't use anything connected to my camera or mount when I'm photographing. I'm trying o keep everything simple. Maybe that's a bit of a down fall for me though. Thanks for the advice though Alex
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Old 25-09-2018, 12:08 PM
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Sharpcap has several ways to help sort out focus (with/without bahtinov mask), but doesn't work with DSLRs. You'd need to use something else - I use AstroPhotographyTool. There are others.

To me (and I might well be wrong) it looks like you need a longer exposure and maybe zoom-in if you are going to see if those diffraction patterns are even. And maybe do it on a nearby brighter star, especially if you are doing this in live-view with the dslr? Or it might be easier on a computer with some sort of imaging thingery (eg the backyard eos, or I used Canon EOS Utilities which is free)
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Old 25-09-2018, 06:54 PM
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Sharpcap has several ways to help sort out focus (with/without bahtinov mask), but doesn't work with DSLRs. You'd need to use something else - I use AstroPhotographyTool. There are others.

To me (and I might well be wrong) it looks like you need a longer exposure and maybe zoom-in if you are going to see if those diffraction patterns are even. And maybe do it on a nearby brighter star, especially if you are doing this in live-view with the dslr? Or it might be easier on a computer with some sort of imaging thingery (eg the backyard eos, or I used Canon EOS Utilities which is free)
Hi Chris.

Thank you for your input. I'm really trying to avoid going down the PC connection path ( much to my detriment ). I'm with you on the more exposure though. The focus shot I posed wasn't from that particular session but it was an example of what I am doing so maybe sometimes I'm getting it closer than others. I'll spend more time trying to get it right in the next session and see how I go. Thank you again for your advice
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Old 25-09-2018, 07:02 PM
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Chris is spot on, for 2070 with your slow scope 22 secs is not even in the ball park. You need at least 60 secs, and preferably a nice dark site that will allow even longer. It doesn't matter how many subs you use, you can't bring out detail that wasn't there in the first place.
raymo.

Last edited by raymo; 25-09-2018 at 07:05 PM. Reason: more text
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Old 25-09-2018, 07:16 PM
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Chris is spot on, for 2070 with your slow scope 22 secs is not even in the ball park. You need at least 60 secs, and preferably a nice dark site that will allow even longer. It doesn't matter how many subs you use, you can't bring out detail that wasn't there in the first place.
raymo.
Thank you Raymo. Your words about the inabilities of slow scopes, unguided, DSLRs on anything other than EQ mounts and perfectly dark sky's is what inpires me
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Old 25-09-2018, 09:45 PM
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Hi Ryan, I wasn't trying to discourage you; I was imaging with a 60mm f/15
scope 65 years ago. I was just pointing out that whilst the more subs the
better is true for image quality, 500 subs won't show any more features
or nebulosity than 50 will. You probably haven't seen any of my stuff that I have posted here over the years, but all were unguided with no separate
darks or flats etc, and I have had several published in S&T, so keep at it.
raymo
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Old 25-09-2018, 10:41 PM
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Hi Raymo,

As I said, I'm not discouraged in the slightest, quite the opposite. If Astrophotography was easy I wouldn't be doing it. When I'm told that something is going to be very difficult / impossible, that's when I sink my teeth in.

I am limited by my equipment and I am well aware of that. There are things that I can change ( focus accuracy, alignment, processing techniques ) and there are things that I can't ( Sky glow, the focal ratio of my scope, tracking smoothness ). I certainly don't post anything for the sake of affirmation, I do it for education. I posted my focus shot so I could be told where I was going wrong and I was, it's not accurate enough. By learning these things now, I can apply them to better equipment later down the track. You don't learn to drive in a formula 1 car but a formula 1 driver can help you learn how to take the corners in your ford focus.

I have seen your work and I think it's great. My equipment will not allow me to do what yours can but I am happy to learn the techniques to get the best out of what I have.
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Old 25-09-2018, 11:39 PM
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Have you thought about using your gear for what it does best, such as
lunar close ups, and the brighter planetary nebulae such as NGC3918 which I have attached? Not meaning that you should give up on your present targets.
raymo

P.S. 3918 needs to be viewed at about 25% screen.
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Last edited by raymo; 25-09-2018 at 11:43 PM. Reason: more text
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Old 25-09-2018, 11:51 PM
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I can't seem to get myself overly interested in anything in the solar system. Visually I might have a look every now and again to make sure they're still there but that's about it lol.

Re: planetary nebulae. I'd be interested in giving them a go. Do you have any other suggestions as well as NGC 3918 ? Keeping in mind that the sky glow here limits me to around magnitude 8-8.5 .
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Old 26-09-2018, 12:26 AM
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I'm away from home at the moment, and have no star charts or reference material with me, but if you google "bright planetary nebulae" you should get a list showing images and magnitudes.3918 is very small, but bright, and easy to locate. M57 [The Ring Nebula] and
M27 are reasonably bright.
raymo

Last edited by raymo; 26-09-2018 at 12:29 AM. Reason: more text
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Old 26-09-2018, 09:41 AM
kencas (Ken)
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Hi Ryan,

If you are using a DSLR, what I did with my Canon 200D/SL2 was purchase an inexpensive 10" IPS LED HD Display screen with HDMI from eBay. This connects to the HDMI out on the camera and gives me a larger screen to see how my focus is. It works really well!

But as an alternative I then went on to buy an X5 mini PC that runs Windows 10 that mounts on the back of the screen, and I will use that to connect to the DSLR directly (but I have yet to connect it up yet). All up cost for the screen and mini PC was under $275.

Ken.
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Old 26-09-2018, 12:16 PM
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Are you using full live view zoom on the brightest star with the bahtinov mask? Pretty hard otherwise. Most DSLR cameras can do that now.

Then focus CCW and hope the temperature does not drop.

I also made a Duncan mask which in theory works on a bright star if the magnification is 200x.


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This is a sample of my focus shots.

Am I doing right?
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Old 26-09-2018, 06:51 PM
RyanJones
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Hi Kencas,

That rounds like a really innovative idea and well within budget thank you for the suggestion. I'll look in to it

Hi Ray,

My 5D is a mark 1 which doesn't have live view so it's a case of take a shot, review it, adjust and take another. I am however using probably not the brightest star but certainly one of the brighter ones, generally nearest my target. I'm not 100% sure but it's likely that shot was Anteres.
Thank you for your input
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