nikon D3100 imaging

[bigbox]

Hi guys, ive been using my d3100 for imaging recently with some fairly good images. Now what i want to know is, the D3100 has vidro capture capability, would i be able to use this to capture avi images of DSO's ETC ETC?

Cheers Ady

[Cornelius Varley]

I think the answer will be no. DSO images require long exposures measured in tens of seconds of minutes, video images are short exposures measured in tenths of seconds.

Peter

[bigbox]

Cheers Peter for that...

if thats the case would it be ok to use just foe planetary instead?

Regards Ady

[Gina]

A webcam is better.

[squeaky]

Hi Ady,

I've just got a D3100 and am struggling to find any instructions/help on using it with my scope (300P Skywatcher).

I talked to the shop I bought the camera from (and the scope, as it happens) and they're saying use "Prime Focus" *** to test, and for DSO's use a 2x Barlow with a short focal length AND an optic with a focal length of 15mm or less.

It's doubtful that I can test this any time soon - I'm getting rained on and will be for the next five days according to forecasts; but if you've got any tips I'd be really grateful. This is my first ever SLR and my first ever try at astro imaging so simple step by step (really REALLY simple) would be good

*** The technique for Prime Focus is to separate the "nose end" of the adaptor from the black tube that holds the optic, and then screw that nose end into the camera adaptor ring. Then fit these to the camera and, obviously, plug it into the scope eyepiece. Use the scope's own focussing while watching "live view" on the camera.

According to one source - the magnification formula is:-

10x mag per 300mm of Focal Length

For my scope that would be 10 X 1500FL / 300 = 50

While another source says I would get 30

[Tinker1947]

You could if its affordable buy a Hyperion 68 Degree EP, these with the T43 Adapter ring (brought separately) allow a DSLR to be attached and therefore take imagines with i assume the magnification of the lens adding to the magnification of the OTA, there are some drawbacks i think doing this sort of image makes for focusing very hard, error in any part of the viewing train will be magnified, there will probably be a need for a Coma Corrector, with the lack of to many stars DSS won't stack a load of subs so only one image might be forth coming so this will require a really long guided exposure, there may be stuff i have typed that's not relevant, there will be stuff i have missed, but to be sure it won't be easy taking this route and it won't be cheap, i personally intent to follow this route as my budget allows and more information comes to light...

[squeaky]

You could if its affordable buy a Hyperion 68 Degree EP, these with the T43 Adapter ring (brought separately) allow a DSLR to be attached and therefore take imagines with i assume the magnification of the lens adding to the magnification of the OTA, there are some drawbacks i think doing this sort of image makes for focusing very hard, error in any part of the viewing train will be magnified, there will probably be a need for a Coma Corrector, with the lack of to many stars DSS won't stack a load of subs so only one image might be forth coming so this will require a really long guided exposure, there may be stuff i have typed that's not relevant, there will be stuff i have missed, but to be sure it won't be easy taking this route and it won't be cheap, i personally intent to follow this route as my budget allows and more information comes to light...

The camera was recommended by the shop as suitable for using with the telescope that they sold me.

I'm still getting rained on, so I can't test... BUT...

The Prime Focus option gives me a possible mag of 50 (though it might only be 30 - and that is below the stated minimum operational mag of 40; so would be useless).

The LOWEST mag with an optic in the train (recommended as a focal length of 15mm or less) would mean, for me, using a 13mm which is a calculated mag of 115. Given that I have to use a x2 Barlow - that's 230.

So I might be able to get mag 50 - but after that my minimum will be 230.

The camera, as a DSLR is great, I'm impressed by it. But as an astro-photography camera it seems to be very limited.

I've already had to pay out for the adaptors and am reluctant to buy any more kit to get this thing to work.

What does the highlighted bit of your post mean, please?

[Mr TamiyaCowboy]

really really simple.

set up scope outside. place T2 mount adapter onto camera body. screw T2 nosecone into camera adapter (prime focus )

put camera and nosepiece into focuser tighten all up, turn on camera. adjust focus onto subject ( if you cannot focus on subject try adding a barlow, this tends to help). using live view zoom into picture and adjust telescope focus very softly.

once in focus activate shutter and take picture.

settings : a high'ish ISO say around 400+ and a longish exposure say around 30/40 seconds. check pictures and adjust settings as needed. the best object to hone skills on is the moon , the moon requires a faster shutter speed so we go from 30/40 seconds to 1/500 - 2000 ( later with full moon).

settings like aperture will not work when hooked to a telescope, so you have to use exposure length and ISO with a little pre test shots. after things are set up you can fire away to hearts content.

[squeaky]

Thanks

It turns out that for my telescope (Skywatcher 300P) a Barlow is a must. The shop I bought my kit from put me on to a guy from Telescope House and I trialled in daylight in between showers late on Thursday. I can get a focus now - though tbh I still can't get a crisp focus. Yet.

I've put together a quick and dirty web page yesterday, with photos, showing the mechanics of setting up each of the two ways of using the Nikon with a telescope...

www.squeaky.org.uk/d3100/

There's no special fancy code on the page so it should translate easily into bulletin board code if you guys think it's worth dotting it into a thread for a specific "Hints and Tips on the D3100"...? I didn't want to push my luck as a newbie by plastering "stuff" all over the place.

Would it be OK if I edited your settings advice into this page? Attributed, of course, and a link back to your full post here.

Edit: Hmm... I need to borrow a Nikon D3100 to take photos of my Nikon...

[Dave]

Hi, I just thought I would add my thoughts here.

I have used Nikons for a while and have had great success (See my Web site below for some examples).

My most recent acquisition was a D5100 and I am really pleased with the results of my latest astro images using it.

To note your original question, I successfully managed to capture an ISS transit across the Moon in December using the video mode.

See the result here: http://stargazerslounge.com/imaging-widefield-special-events-comets/166966-yet-another-iss-lunar-transit.html

Anyway, moving on.

I used to use an inch and a quarter adapter in the way you have shown on your Web page when I first started out, but it produces two problems:

1. The camera is too far out to reach focus (as you have found). A Barlow will help you reach focus but it reduces the field of view so you are looking at a small portion of sky.

2. Severe Vignetting of the images.

On many telescopes you can unscrew the inch and a quarter adapter from the focusser and attach your camera using a T-ring directly on that.

You will then be able to reach prime focus directly.

When taking images with a camera you don't really measure the magnification but the field of view that is captured with that telescope / camera combination.

Use CCDCalc The New CCD Astronomy Home Page a free utility to show you how some objects will be framed using your set up.

You can add your telescope and camera and see what field of view you can get and what effect Barlows etc, have on that field.

But just remember, the smaller the field of view with your set-up, the fainter the objects will appear. As a consequence, you will need longer exposures to reveal your objects, the tracking will need to be much more accurate, so you will be making problems for yourself right from the beginning if you jump straight into using a Barlow which gives you a smaller field of view.

So if you can find a way to attach your camera directly to reach prime focus, it will make things much easier for you.

Hope this helps?

Dave

[squeaky]

Wow, thank you!

Yes, I can remove the 1.25 inch adaptor, so I'll try the fit. Then, if it ever stops raining down here in Sunny Suffolk I'll try some test shots. If it works I'll add a photo set to the web page. Actually I'll do that even if it doesn't since it may help others with different telescopes.

Yes, I understand that FOV is all... but approximate magnification is more or less universal across equipment and allows readers to then calculate what field of view they will get on their own scopes. Ish

Thanks for the calculation link - I'll add that into the page too.

I guess it would be a good idea to add that formula into the page, along with your helpful comments there.

Equally, in case it isn't blindingly obvious, I should add in a note (EARLY) to say that this is my very first SLR and my very first attempt at astro photography AND this is a new scope!. So I've got a great deal to learn and the page will evolve as my own knowledge and experience does.

Finally, I found that in my daylight tests I still couldn't get a crisp focus so I'm hoping that setting up as you suggest might give me better results there.

The thing is that I'm a bit limited physically and the 300P is right at the limit of my ability to move around and set up. It takes me an hour to get everything out and ready to view, by which time I'm pretty shattered; so after some time viewing/testing(mostly testing) it then takes me more than an hour to break it down and get it packed away back inside the house. So in showery weather such as we are getting here I can't risk "popping out for a quick test" unless I'm SURE of a three hour window of opportunity. Since my scope arrived in early April I've had just two one hour night viewing sessions (both at home near a large town with light pollution) and my camera arrived a couple of weeks later and I've had exactly zero night opportunities for testing - and only two daylight test sessions. The first of which I couldn't get any sort of focus in, and the second to test the suggestions you've seen on my page. According to the weather forecast I *may* get a chance for a daylight test this Sunday afternoon.

Tracking I haven't tried yet - but I'm pretty sure I can get inside 10 arc secs of the celestial north pole and maybe, with practise, inside 2 arc secs. How accurate do you need to be to get a stable photo on a thirty second exposure?

Last thing... I see that you're a moderator so you're the best person to tell me... I'm happy to translate the web page into BB Code and start a Tips thread with it... that way it should be easy to maintain with updates from tip posts by members along with links to the actual posts for any further information in them and... such a thread here is more likely to show up on Google than my single lonely page which I'd then be happy to scrap. Your thoughts?

Richard

[mario11]

Some DSO with my Nikon D3100

Ciubarec Astro Page: Photos

[squeaky]

Brilliant!

PLEASE tell me/us/everybody just how you got those. As in physical fitting of the camera to your scope AND the settings you used on the camera.

OH, and post photo editing tips!

Pretend I'm an idiot. (I'm not really an idiot - but I'm VERY new to all this and I know nowt.)

Back story... a long time ago, in a galaxy far away... I was a keen amateur as a young lad, but when I joined the Navy I sold off all my stuff. Telescopes don't work very well on ships. Once I'd done my time life kinda kept in the way of getting back into it though I watched all TV progs on anything to do with space, astronomy, cosmology...

Nowadays, though unwell, I have the time and, more importantly I guess, was able to commute an old scrag end of a pension which got me enough to buy the nice new shiny kit that I now have,

All I've got to do is learn how to use it

[squeaky]

Phew! After reading so much, and having my poor old brain turn into grey flupp I decided to try the moon this evening at dusk... around 20:15...

So here's my first ever astro photo...

Click to see full size.

I'm sure that my post production could be better - so if you'd like to show me how it's really done, the original .NEF raw file is here... DSC_0087.NEF

That's taken on my 12" Skywatcher 300P Flex Auto using the Prime Focus with a 2x Barlow. Nominal magnification is 80x and roughly FOV is 30'

I've got a complete mosaic set at this mag ready to stitch together, another complete set using my 3x Barlow, and a couple of test shots using my 5x powermate. Yet to try using optics. Boy but they fill up my 1GB card quickly!

I'm shattered - but if I can stay awake long enough I'll try for Mars and Saturn too tonight.

to everyone who has given me pointers here.

And I say again...

Woo Hoo !!

[bigbox]

Thats a cracking first pic, well done.

[squeaky]

Thank you kind sir.

I have to admit, given that this is my very first... with practice I might get the odd REALLY good shot.

I was using point and shoot, so to speak, with the telescope - didn't even set up the goto, much less the tracking. Too many clouds around this evening.

So... need to drive about 20 miles on a good night to find a darker sky than mine is, and then set up tracking and try my hand at the planets. Point and shoot didn't really work for Mars and Venus.

Now I've got to get all my kit back indoors. To coin a phrase... "I may be gone some time"

[squeaky]

Couldn't sleep. Same photo, but tweaked with the NX2 software supplied with the camera... and then polished with Paint Shop Pro 10.

Hmm...

[Dave]

Nice one Richard,

You've now started down that long slippery slope of imaging.

Welcome aboard.

Dave

[squeaky]

It's not a slippery slope at all... it's a chuffin' bottomless precipice! (oh, and thanks )

The NX2 software seems a bit limited in what it can do - but seems to do it well.

Until you then stick the results into Paint Shop Pro and play some more.

I've seen so many different "versions" of this image while trying different settings that I've completely forgotten what the moon actually looked like yesterday. <sigh>

Query - does anybody know if there's a way to set the live view in the D3100 to only show a small part of the image? It's really hard to tell how well it is really focussed when viewing the entire 4600x3000 (ish) picture on that screen. If the screen could be set to show a fifth or a tenth of the image I'm sure I could get a crisper focus and so need a whole lot less processing.

Query 2 - a number of people when listing their cameras say... (unmodded). Erm... you can do mods???

[Dave]

Hi Richard,

In live view you should be able to press the + magnifying glass to zoom in to help focus a bit better. Get or make yourself a Bahtinov Mask. Focus on a bright star using the mask and then go back to the Moon to image that. (Don't forget to take the mask off again before imaging).

Also try taking multiple images of the same subject and average them together. It gets rid of a lot of noise and smoothes out the image nicely.

Dave

[squeaky]

Hi Richard,

In live view you should be able to press the + magnifying glass to zoom in to help focus a bit better.

Blimey, how the heck did I manage to miss THAT?! Sheesh!

Get or make yourself a Bahtinov Mask. Focus on a bright star using the mask and then go back to the Moon to image that. (Don't forget to take the mask off again before imaging).

Hmm... yes, forgot the tip on focussing on a star before shifting to a planet (or the moon) <sigh> I've been so hung up on trying to learn how to use the camera just to shoot that these "obvious" things just passed me by. OK... so who's got an "in" with the weather gods?

The Bahtinov Mask looks neat. Must do more reading on that.

Also try taking multiple images of the same subject and average them together. It gets rid of a lot of noise and smoothes out the image nicely.

Dave

I don't think any of the imaging software I have does image merging. Any good freeware for this? PSP might do it... I don't think I've ever used more than a tenth of its capabilities. MORE reading...

But I must admit I'm dead chuffed with my first attempt. In fact...

...

...

..wait for it...

...

I'm over the moon!

[Dave]

...

I'm over the moon!

And so you should be too.

[squeaky]

Darn it - it looks like we're going to have a clear and cloud free night here tonight - and there's no way I can take advantage of it. Having put the kit out twice yesterday I'm really paying for it today. I need an astronomy buddy methinks; someone who an do all the setting up in return for viewing time.

[squeaky]

Light full overcast has moved in. I'd have hated to miss a good viewing night.

Anyway I found this... astrojargon - Bahtinov Focusing Mask Generator: Version 0.4

Had to resize it to fit my scope and, in fact, print it in quarters. If anyone else with a twelve inch scope wants one I can hand them the files.

I cheated... printed them on transparencies and then laminated them and stuck them all together. Saves having to cut holes. Just need to find out if the light from stars will get through OK or whether it reeally has to be holes.

[squeaky]

On many telescopes you can unscrew the inch and a quarter adapter from the focusser and attach your camera using a T-ring directly on that.

You will then be able to reach prime focus directly.

Forgot to say... (sorry)... that I tried this on Sunday but couldn't get a focus. Nonetheless I've added the option to the web page in case it is of help to others.

Thanks