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New to DSLR Astrophotography

Kelowna_Dave

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Kelowna_Dave

Kelowna_Dave

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Hi everyone. I am not only new to Stargazers Lounge, but am also new to Astrophotography.

I've read a number of helpful hints in the Stargazers lounge, but haven't been able to find the detail I am missing.

I am using a Canon XTi with Nebulosity 3  and am having real trouble focussing. Best I can get are blobs of stars... like paint spots.

I suspect the problem  stems from the fact I can't seem to find the right combination of ISO and F/stop. All I get when I use the Frame and Focus option are pages of multicoloured pixels, no stars.. This is especially so with short durations (ie)<10seconds.  Fine Focus attempts give me a jumble of pixels in the upper left panel, unlike the nice star which is the demo on the Nebulosity web site.. The only time I get stars is when I set a longer duration (ie) >35 sec and use the Preview option. Doesn't help with Fine Focussing though.

Setting used: F/4.0 ISO 1600, 800, 400 and 200.

I'd appreciate any helpful advice.

Thanks

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ronin

ronin

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I assume that we are talking camera on tripod here, with a canon lens attached?

Jsut to cover what I would expect, camera is set to fully manual, and manual focus is set.

If so then you need to focus on something bright enough to give a sharp image. If the moon is floating around try that, otherwise Arcturus, Deneb, Vega come to mind. Then make sure the focus cannot move.

ISO not really any idea but try 400 then 800, 1600 as well - may as well experiment.

F/4 may be a little wide so try f/5.6, the smaller f number should sharpen things up a little.

Exposure 20 sec then 30 sec, after 30 seconds I would expect trailing to occur.

Check the manual and have the camera set to take it's own darks - sorry I forget the name it comes under. It will take the exposure you set, then take another of equal length with the shutter closed, and then subtract one from the other.

You will need a Release Timer to prevent/minimise any shake, and a reasonable tripod.

Cannot think of much else to suggest.

Friends parents are in Kelowna, know anyone called Watmough ? :confused:

Suppose you may not know if Ken Curley is still in Westbank ? :rolleyes:

Smaller world then you think isn't it. :eek: :eek: :eek:

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Kelowna_Dave

Kelowna_Dave

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Thanks for all the replies everyone.

I should have included the rest of the details:

Telescope: 6" Astro-Graph (Ritchie Cretien)  F9

I use a single 2" extension which seems to get me very close and I still have a few cm of room.

I also have two 1" extensions which I add (total is then 4") to focus visually. This only barely works as I have to leave 1/2 the eyepiece barrel outside to focus. I wish I'd bought two 2" and a single 1" extension instead.

Next time out I'll try  extending to 3" using the 2" plus a single 1", but I am quite sure this will be too much. However, it costs nothing but time to try.

Mount: NEQ6

Camera: Canon Rebel XTi (400D)

Shutter Control Adapter: DSUSB from Shoestring Astronomy

Imaging Software : Nebulosity 3 from Stark Labs

Guide Scope: Kwiq Guider from KW Telescope (not used as yet, once I figure out how to focus, then I'll include guiding  using PHD also Stark Labs)

thanks again

david

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JamesF

JamesF

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Welcome to SGL

I'd second the recommendation to give Backyard EOS (BYE) or Astrophotography Tool (APT) a try instead of Nebulosity.  Focusing is tricky.  I'm sure all three applications have a tool that will give you FWHM figures for stars in a frame, so perhaps the way to start is to keep taking images and checking the FWHM figure to get it as low as possible.  The other way to try focusing would be with a Bahtinov mask.  You can buy them or make your own -- there are template generators on the web.  Then you just slew to a bright star (Altair is probably a good candidate at the moment) and adjust the focus until the centre line splits the "X" through the centre.

Because you're using a such a long focal length scope you're probably going to need fairly long exposures to get much in the way of a usable image.  Thirty seconds doesn't sound unreasonable to me.  If you're using a Bahtinov mask on a bright star you won't need anything like as long.

James

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Kelowna_Dave

Kelowna_Dave

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Welcome to SGL

I'd second the recommendation to give Backyard EOS (BYE) or Astrophotography Tool (APT) a try instead of Nebulosity.  Focusing is tricky.  I'm sure all three applications have a tool that will give you FWHM figures for stars in a frame, so perhaps the way to start is to keep taking images and checking the FWHM figure to get it as low as possible.  The other way to try focusing would be with a Bahtinov mask.  You can buy them or make your own -- there are template generators on the web.  Then you just slew to a bright star (Altair is probably a good candidate at the moment) and adjust the focus until the centre line splits the "X" through the centre.

Because you're using a such a long focal length scope you're probably going to need fairly long exposures to get much in the way of a usable image.  Thirty seconds doesn't sound unreasonable to me.  If you're using a Bahtinov mask on a bright star you won't need anything like as long.

James

I had a read on the BYE website and will get a trial license tomorrow morning.  I do really like Nebulosity. I use PaintShopPro X3 which seems to result in very little additional improvement to the Nebulosity produced .tiff or .png. 

I have used a Bahtinov (my wife made one specifically for my RC.) with some success, but now believe I should have used a brighter star. Both Arcturus and Altair are good  right now, so I'll have another go with the Bahtinov.

I made 20 images of 1 minute of M13. The only ones I tossed out were the ones taken while I was stomping around next to the tripod and inadvertently jiggling the carmera. I've now learned to get the imaging process underway and leave the sundeck until the imaging session is complete.

I took 20 images of M57 at 35 seconds and again had to toss out 3 due to my clumsiness. 17/20 isn't probably too bad. Focus wasn't perfect, but not too bad for a rank amateur.

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Russe

Russe

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Welcome!

I've just gone through the same phase... My main problem was at first the Newtonian wouldn't allow focus, then the wrong adapters and and and. So, hang on in there!

I second APT. The way I do it with my 450D is, I align my mount with alignmaster visually and pop the camera in, focus on this 2nd star with 2-5s exposures in small jpg format. Once spot on, I do a 2nd alignmaster run with the camera inside (400D doesn't support liveview - so you need to work again with short small exposures). Then I go to my target, pop the guidecam in, PHD callibration, wait for PHD to settle, and off I go.

For focusing I use a Bahtinov. If it's self-made - could there be an issue with that?

Can you achieve focus with your camera & scope in daylight?

Is your scope collimated?

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Kelowna_Dave

Kelowna_Dave

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Welcome!

I've just gone through the same phase... My main problem was at first the Newtonian wouldn't allow focus, then the wrong adapters and and and. So, hang on in there!

I second APT. The way I do it with my 450D is, I align my mount with alignmaster visually and pop the camera in, focus on this 2nd star with 2-5s exposures in small jpg format. Once spot on, I do a 2nd alignmaster run with the camera inside (400D doesn't support liveview - so you need to work again with short small exposures). Then I go to my target, pop the guidecam in, PHD callibration, wait for PHD to settle, and off I go.

For focusing I use a Bahtinov. If it's self-made - could there be an issue with that?

Can you achieve focus with your camera & scope in daylight?

Is your scope collimated?

Thanks for the suggestions.

I check collimation and adjust as required before any visual or photography session. It;s a good point though. I'm quite pleased with my efforts to polar align my NEQ6 , even with a one star alignment it's quite easy to locate targets. Due to the limitations of my setup location I can't do a 3 star and even a 2 star is a pain.  Once I'm satisfied I have everything uinder control, I'll move off my sundeck and into my backyard where I'll have a much broader sky to use.

It seems everytime I go over the tips/ docs/ videos, I find some detail I missed. Hence the focussing is getting much much better. Patience with good seeing is what I need now. I was out the other night but the seeing was terrible and there was plenty of cirrus ( and occasional altocumulus) drifting around. Pretty close to decent images, but am eager to get out again as soon as possible. I also incorporated guiding with PHD the other night and was amazed at how simple and effective it was. Instead being restricted to 30sec images, I was doing 5 minutes and noted with few exceptions the stars were nice and round rather than a streak. Due to my sundeck setup location, I can expect to toss image #1 due to the camera jiggle as I walk away from the setup. It doesn't take much to ruin an image.

I do have a Bahtinov and I'll see if the comination of Bahtinov coupled with Nebulosity 3 gets quicker results.

david

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Bignev

Bignev

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Hi there and welcome,

                                    Just a quick note to try and cheer you up a bit, I have just started up too and i am having a right old mess of a time to try and sort out the settings

on my 1100D which i got for my pictures, spent many a night there now and i still aint managed to get one good picture of jupiter yet. Nebulea are not bad but planets

are still a bit of a mess with me all i get are white balls, anyways good luck with your pictures, just why do all great things have to be a pain at the start eh.

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Kelowna_Dave

Kelowna_Dave

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Great news! Incidentally, what are your PHD brain settings for what guidecam on which guidescope?

hi Russ

Here's an image of  the advanced setting I use with PHD. Seem to work fine. I have the same guidecam as you. It's the Kwiq guider which is a QHY5 on a 9x50 finder scope. Hope this helps if you're having problems.

dave

post-32170-0-61467200-1381344164_thumb.p

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