Some basic imaging. What do I need?

[Nigele2]

Morning all.  Had a great session last night which having seen the forecast came literally out of the blue.  I started by looking at moonie in daylight and Jupiter in half day/night.  We have to grab what we can at the moment I think all UKites will agree    Towards the end as the clouds moved in I was looking for clusters in Auriga (last bit of clear sky).  Think I found M36.  Then thought although sophisticated imaging is not a current desire wouldn't it be good to take a snap to check with the charts when the session is over.  (I normally draw a quick sketch but my hurried drawing in the dark of this cluster could have been any one of half a dozen clusters   ).

OK I have the scopes and I have a Canon SLR EOS (with just a basic 18-55 tourist zoom).  

Am I right in thinking I just need a T-ring. And a snap of say 1.25 seconds will give me an image?  Possibly with a 2.5 Barlow?  ok not what you guys call an image but good enough to see that it was indeed M36.

Or do I also need a tele extender to accomodate EPs?

Or is it more complex than that?

Sorry keep reading and just getting confused.  And don't want to splash the cash and find I'm missing something.  

Cheers for any help and here's hoping for clear skies 

[jgs001]

If you're using a refractor, on a tracking mount (based on your sig), you ought to be able to achieve something... You'll need a T ring, and almost certainly an extension tube to enable you to get focus with the camera. You'll need to see how long an exposure you can get, but I'd expect you to probably need more than 1.25s to get enough detail in the image. I tried a 1s exposure with an f/2.8 camera lens wide open, and I could tell it was the Hyades in the shot, but it was lacking. Do not use a barlow, as this will make you're exposure times way too long. A 2x barlow, requires you to get 4x the exposure time. 

[Langy]

One thing I have found is that I have to use a barlows or my focusing point is too far away where I will need to either shorten or lengthen it to focus, so I can only focus when through the barlows. This is OK for now as I'm new to it all and the moon is an ideal subject for this situation with exposure times of around 1/200 second.

I did create a post a few days ago on exposure times as below. To capture any stars you will need some lengthy times but the longer focal length you get the less time you can expose for unless you have a very good tracking system. Experimenting will be the key. 

http://stargazerslounge.com/topic/207597-partial-tracking-exposure-calculation/

If you haven't a good system to take long exposures I'd recommend just taking longer exposures with your 18-55 on a tripod. I've not had much success with the wider aspect of this but sticking on my 75-300mm lens at the 300mm setting with lots of 1.3 second exposures and stacking as in the example video below has got me some reasonable results.

http://www.youtube.com/watch?v=e0JSTF8SGi4&list=WLpWIx6AVA0qogAX0syRenFPf3pGFWEB6K

The image below is of the Seven Sisters which doesn't justify the actual view through the EP, this was 300mm lens on a tripod.

If you do take images there is a group in Flickr that you can post them to where you get lots of details back about what is in the image.

[jgs001]

Sorry, I forgot to mention you may need a ep push fit tube to attach to the Tring... but that'll depend on the tubes and fittings you have available.

[Nigele2]

Tx John for the reply.  I don't normally use tracking as that relates to my reflector.  The refractor is a bit heavy for the motorised mount. But the refractor is soooo good I doubt I'll ever spend much time with the reflector - in fact EBay beckons.  But presumably even a bit of very basic stacking without tracking might give me something?

............................................ and almost certainly an extension tube to enable you to get focus with the camera. 

So the extension tube is not the same as a tele extender which accomodates EPs?  Or does a tele extender act as an extension as well?

Thanks for the tip about the Barlow.  Of course now you mention it it seems logical.  More glass between camera and in this case cluster.

Cheers Nigel

[Nigele2]

Langy tx for that.  Th problem is which tubes to buy.  But from the sounds of it just jumping in with a Canon kit on EBay and see what I get is the way to go.  A pain to get it set up and discover I can't focus and need to buy more tubes but c'est la vie.

For sure your image of The Pleiades would be good enough for my purposes.  Yes M36 is smaller and not as bright but key stars are of magnitude 9.  

Luckily don't need a tripod as camera can sit on top off my refractor.  So I'll give that a go but I feel the image will be too small.  But interesting cost free test.

Cheers Nigel

[ronin]

You should be doing what is called "prime focus".

Basically you use the body only of the camera and add a T-ring to the body and attach this now weird looking lot to the focuser.

Then you adjust the focuser to get an image on the camera sensor.

Keep it simple and forget eyepieces and barlows.

You will need live view to see what you are pointed at and to get a reasonable focused image.

Set the camera to MANUAL, everything manual.

Forget the f/number/aperture, it is fixed by the scope.

Set an exposure of say 20-30 seconds.

Set the ISO to 1600, 3200 or 6400, basically as high as you can get.

Then press the take picture button.

Much better if the scope is on an equitorially aligned motor driven mount. You could increase the exposure to 40-60 seconds. 30 seconds on a fixed mount will just start to show trailing, but you might need that length of time to get anything useful.

There are things calle Remote Timers from Amazon made by Shoot that will enable long exposures and then no shake from you pressing anything, about £25.

Check the camera instructions for getting the camera to take a noise "suppression" image. The camera will take a normal exposure and a "dark" it then removes the drak from the normal to remove noise. This doubles the exposure duration.

First attemts will be trial and error.

[Langy]

Langy tx for that.  Th problem is which tubes to buy.  But from the sounds of it just jumping in with a Canon kit on EBay and see what I get is the way to go.  A pain to get it set up and discover I can't focus and need to buy more tubes but c'est la vie.

For sure your image of The Pleiades would be good enough for my purposes.  Yes M36 is smaller and not as bright but key stars are of magnitude 9.  

Luckily don't need a tripod as camera can sit on top off my refractor.  So I'll give that a go but I feel the image will be too small.  But interesting cost free test.

Cheers Nigel

The Pleiadies image was a stacked image where something like 60 1.3 second exposures were used, so it will not be a quick thing.

As suggested a remote is ideal if not essential, I bought one off eBay a year or so ago before I got into Astronomy something similar to the link below. I paid about £15 for mine which the key thing was to take time lapse images. With these you can set the camera to Bulb and set all the time settings on the control in whole seconds though. So you can program it to take 100 shots at 1 second exposures and take one every few seconds to allow the data to be saved to the card. This is great as you can kick it off and walk away from the camera and let it do its own thing. However if I'm near the camera I tend to set the time on the camera and set it to continuous shoot mode and just hold down the button to take several images, wait a few seconds for them to be saved and go again.

http://www.ebay.co.uk/itm/Timer-Remote-Cord-For-Canon-EOS-Rebel-GII-EOS-Rebel-X-/390388231389?pt=UK_Photography_DigitalCamAccess_RL&hash=item5ae4f3acdd

Personally unless you have some good tracking prime focus will not be very good, piggy back with a longer lens would be better but lots of images will be required to stack in DSS. Have a go with you 18-55 at 55 see how long of an exposure you can get, using the 600 rule you should get around 6 seconds per exposure without trailing stars and no tracking on the mount.

Your other option, as you mentioned charts. Why not print and laminate charts, you can then mark on them while you are there with a washable pen.

[Nigele2]

Your other option, as you mentioned charts. Why not print and laminate charts, you can then mark on them while you are there with a washable pen.

Paul wish I rated my navigational skills as highly as you do 

But tx all that has got me going with some way forward and pushed up the enthusiasm level.  Odd the way just talking about this stuff stimulates the juices and gets you staring out the window and opening weather forecasts.  Sadly both indicate little hope beyond a little window of opportunity this evening.  Where's that camera? 

[jgs001]

Are you talking about using the Bresser ?? That's f/5 which is pretty fast, but at 1s, which might be pushing the exposure limits, you're really not going to get a lot of light into the system for the camera to view. Even f/2.8 which lets in nearly 4x as much light, really is a bit slow at 1s. If you can, and I don't know if they're available, but a motor drive for that EXOS-1 mount would be a good idea. Or you could try and use the slow mo controls and track it by hand, but that's going to be a lot harder

[Nigele2]

Set the camera to MANUAL, everything manual.

Forget the f/number/aperture, it is fixed by the scope.

Set an exposure of say 20-30 seconds.

Set the ISO to 1600, 3200 or 6400, basically as high as you can get.

Then press the take picture button.

Ronin tried that in daylight and looking good.  Will return with results soon.  Tx 

Are you talking about using the Bresser ?? That's f/5 which is pretty fast, but at 1s, which might be pushing the exposure limits, you're really not going to get a lot of light into the system for the camera to view. Even f/2.8 which lets in nearly 4x as much light, really is a bit slow at 1s. If you can, and I don't know if they're available, but a motor drive for that EXOS-1 mount would be a good idea. Or you could try and use the slow mo controls and track it by hand, but that's going to be a lot harder

John it will be the Bresser.  Just all round so superior in quality of viewing and a total pleasure to use compared to my reflector (even with its GOTO and motors).   It would have to be a very big reflector to get it away from me.  So image limitations or not it is what I will work with    Buying it a tracker is a future option but I don't really want to go back to that if I can avoid it.

Stacking is not an issue as not knowing what I'm looking at at the time doesn't diminish the pleasure so that might be the way to go.  I saw a video of a guy without tracking taking an image of andromeda and the result was spectacular.  

But I'll be back with something soon so fingers crossed 

[russ]

Nigel,  what setup was the guy using who took the Andromeda image?  I can't imagine a DSLR recording anything of M31 in 1 second, even with the ISO maxxed out.

I have the same mount by the way. Came with an N130 newt but i have a loaned ED80 on it now. Its a good solid mount on a solid tripod. Definitely a good basis for your imaging.

Do you mind me asking why you are against the RA drive?

[Langy]

Nigel,  what setup was the guy using who took the Andromeda image?  I can't imagine a DSLR recording anything of M31 in 1 second, even with the ISO maxxed out.

It's in the YouTube link I posted at the top of this post. Normal DSLR something like 300 or 400mm lens.

[Nigele2]

Nigel,  what setup was the guy using who took the Andromeda image?  I can't imagine a DSLR recording anything of M31 in 1 second, even with the ISO maxxed out.

   A 280mm lens on his camera.  So not a telescope but a nice video from a down to earth guy.

I have the same mount by the way. Came with an N130 newt but i have a loaned ED80 on it now. Its a good solid mount on a solid tripod. Definitely a good basis for your imaging.

Do you mind me asking why you are against the RA drive?

Russ each to his own of course but I started with motorised GOTO and now I have a fully manual set up.  Yup I'm weird    For me I just want to be wandering in space.  The simpler the process the more real it is.  I don't need noise (well unnatural noise - the odd owl is always welcome).  And I don't want to rush down a messier list ticking boxes (did my train spotting as a kid).  And I want the pleasure of hunting down things like M36 (I'm fairly sure that is what it was - I'm not going to own up as to whether that was what I was looking for  ).  If the clouds hadn't arrived I would have mapped out the area and found his friends and I'd have found that much more rewarding than jumping around with a GOTO.  But that's what gives me a buzz.  As I said 'weird but true 

[russ]

It's in the YouTube link I posted at the top of this post. Normal DSLR something like 300 or 400mm lens.

Nice tutorial. I wonder what the limiting magnitude of his skies are?

[Nigele2]

Sorry guys and mods.  Didn't expect the video to pop up here      Just wanted the link for anyone interested.

[russ]

Russ each to his own of course but I started with motorised GOTO and now I have a fully manual set up.  Yup I'm weird    For me I just want to be wandering in space.  The simpler the process the more real it is.  I don't need noise (well unnatural noise - the odd owl is always welcome).  And I don't want to rush down a messier list ticking boxes (did my train spotting as a kid).  And I want the pleasure of hunting down things like M36 (I'm fairly sure that is what it was - I'm not going to own up as to whether that was what I was looking for  ).  If the clouds hadn't arrived I would have mapped out the area and found his friends and I'd have found that much more rewarding than jumping around with a GOTO.  But that's what gives me a buzz.  As I said 'weird but true 

Nigel, i think you may have the wrong impression of what the RA tracking motor does for the EXOS-1. It won't find anything for you, it won't get in the way of your simple astro life  And it doesn't make a noise, not even a hint of noise. It merely moves the RA axis at the same speed as the spinning Earth. You can still use the mount as you do now but as soon as you lock the RA axis it will immediately start tracking the stars. Totally unobtrusive. And like chalk and cheese compared to your Goto mount.

The only added complication is the need to roughly polar align the mount, which you should be doing now anyway to get the most from it (even without motors).

By the way the RA motor is £83 from Telescope House.

[Nigele2]

Nigel, i think you may have the wrong impression of what the RA tracking motor does for the EXOS-1. It won't find anything for you, it won't get in the way of your simple astro life  And it doesn't make a noise, not even a hint of noise. It merely moves the RA axis at the same speed as the spinning Earth. You can still use the mount as you do now but as soon as you lock the RA axis it will immediately start tracking the stars. Totally unobtrusive. And like chalk and cheese compared to your Goto mount.

The only added complication is the need to roughly polar align the mount, which you should be doing now anyway to get the most from it (even without motors).

By the way the RA motor is £83 from Telescope House.

Now Russ that sounds like even technology I could allow to creep into my world.  You're right I had no idea a simple RA existed.  It could answer my problem perfectly.  Now how much is it???  Get the plastic ready.  I may have to put the Delos on hold    Tx Russ

[russ]

Now Russ that sounds like even technology I could allow to creep into my world.  You're right I had no idea a simple RA existed.  It could answer my problem perfectly.  Now how much is it???  Get the plastic ready.  I may have to put the Delos on hold    Tx Russ

I had a feeling that was the case.  Its only a simple drive but it should allow you to capture much longer exposures. Not sure how long, that will be down to experimentation. But in the past i have used EQ3-2 and EQ5 mounts with simple drives to capture upto 2min exposures through various short focal length scopes. And if you mounted the camera directly to mount or to the top of the scope and shot through the camera lens, then that exposure time should be considerably more. Especially widefield with the 18-55 kit lens. The problem then would be light pollution (i'm in Eastleigh, so our LP can be poor if the railway switch on their lights).

[Langy]

I had a feeling that was the case.  Its only a simple drive but it should allow you to capture much longer exposures. Not sure how long, that will be down to experimentation. But in the past i have used EQ3-2 and EQ5 mounts with simple drives to capture upto 2min exposures through various short focal length scopes. And if you mounted the camera directly to mount or to the top of the scope and shot through the camera lens, then that exposure time should be considerably more. Especially widefield with the 18-55 kit lens. The problem then would be light pollution (i'm in Eastleigh, so our LP can be poor if the railway switch on their lights).

That's what my other link http://stargazerslounge.com/topic/207597-partial-tracking-exposure-calculation/ was all about the calculations of using a simple RA motor which I now have.

Last night I could keep the moon and Jupiter (at different times when I viewed each) in frame on the webcam. I had to do some adjustment as I was viewing it to speed up and slow down and manually alter the Dec as not fully polar aligned, but that way I would be able to get longer exposures compared to no MD.

[jgs001]

That's the drive I meant... a simple thing that just turns the mount head ... It'll extend your exposures from 1 sec to something usable for what you want... even 30 seconds should be sufficient I'd think for your plan. Even just the one shot may be sufficient.

Just one warning... It's a slippery road from here... downhill to wanting a full imaging setup ...

[Langy]

That's the drive I meant... a simple thing that just turns the mount head ... It'll extend your exposures from 1 sec to something usable for what you want... even 30 seconds should be sufficient I'd think for your plan. Even just the one shot may be sufficient.

Just one warning... It's a slippery road from here... downhill to wanting a full imaging setup ...

Well the pockets are fairly shallow, but I've always worked with equipment that doesn't match the majority and will always try to get the best I can from it.

[russ]

I must admit i had to double take when i saw the price of £83. It's been a while since i bought a new RA drive, the last time i looked (probably a good 5 years ago) they were only £50. But it will still be money well spent to vastly improve the capabilities of the mount. Both for visual and imaging. Be able to centre an object and have it stay there while you take in the details is a big help. So definitely worth the investment.  

[Langy]

Yes mine was only £33 which was actually cheaper than buying it with the scope as new.

Got to admit it's a real dream just having to tweak the speed button as you view, but not having the slow motion cable is a loss for centering the image to start with, especially if when tightening the clutch it goes out of center.

[Nigele2]

Just progress update:

Telescope House confirmed the RA motor was good and offered some general advice in an email.  RA is now in situ (£83).  Haven't tried it yet as no batteries (not AA as my GOTO  ) but looks simple enough (as you said Russ  ).

Now have 2 TRings and two extenders (different lengths and one adjustable) - don't ask   .  At first I attached the camera in daylight but couldn't get focus on very distant objects.  Used a Barlow*2 and that helped.  Nice shot of a lamppost and a chimney.  Night came so tried without Barlow but not enough inward travel to get moonie in focus.  Had the extenders not both been for EPs, just a basic short ones I'm sure it would have been ok.  Anyways dropped in a 17mm EP (so glad didn't get rid of stock EPs as these fit) and there was moonie rather big but in good focus.  Took some shots using various settings and some reasonable stuff and some blobs.  I should say by now moonie was very high in the sky, it was storm force 8 and clouds were continuously blocking the view but you know what it is like with new stuff   Tried Jupiter but no luck- just darkness but had no right to expect anything but.

Onwards and upwards as soon as the weather permits.  Cheers Nigel