Any (novice) guys into astrophotography?

[Intervention302]

Hey guys,

Just signed up and loving the site. Been doing a lot of reading and trying to learn my new camera Nikon D60

Anyway, my main field of interest is with automotive photography. However, I've always been interested using my telescope to look at planets and different DSO (deep sky objects)

I have a z8 (8" dobsonian) telescope. Now I know its possible to hook the D60 to a telescope. I think its called a T-Ring. I'll do more reading after my shift, just was wondering if anybody has attempted it and the overall difficulty

Also, I'd love to try to snap some photos of a super dark and clear starry night way up north with no pollution lighting. Anybody attempt that either?

Thanks for any help

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[Overread]

Not tried it myself; but read a little on the subject here and there. A lot of the exposures you'll need to make will need long exposures and a high ISO; as such do some reading around:

1) Photo stacking - this is where you combine a series of exposures into a single exposure; the idea is that you can take a long exposure of the sky by breaking it into little parts instead of all at once. This helps cut down on noise as when the camera sensor heats up (as exposures start to take minutes if not 30 mins or longer) it generates more noise.

2) Long exposure noise reduction - check camera manual for details on this

3) Tripod mounts. If you want to do a long exposure you need a tripod that will track the motion of the earth otherwise what will happen is you'll get stars causing star trails over the photo.


Also note a telephoto lens can do a lot as well and might give better performance since its corrected for producing a photograph (whilst a telescope is not).

 

[Intervention302]

Thanks for the quick reply.

Did some quick reading and it seems slightly more complicated than first thought

I know you need a Nikon T-Ring and then a T-Adapter.

But the problem arises when you try to get the objects into focus. You need to get the camera the exact distance away from the focuser and I can't find solid info on what length I'd need

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[jsecordphoto]

I recently got into landscape astrophotography, there are a few other guys around NH who are seriously talented. I realize you were talking more about true astrophotography with a telescope though.

 

[Edsport]

For taking photos through a telescope you're gonna need a tracking device to counteract earth's rotational movement...

 

[JerryLove]

Don't know if you've already taken this into account: but does your telescope auto-track? Even with relatively modest telescopes (the kind where you can check out Saturn's rings), the rotation of the Earth causes visible movement across the field of view within the timeframes that a long ISO would take up.

 

[Propsguy]

Using a barlow may get your image into focus if you can't get the t-mounted camera close enough with your existing focus rack. The best way to check if you can mount your body with the t-ring and achieve focus is to buy it and try it.... There are a couple of kits out there that include adapter hardware that you can try in various combinations. If no combinations work, try the barlow (which creates some problems as it increases magnification), but it will get your sensor in the right spot.

 

[astroNikon]

First of all there's a nice write up on TPF on astrophotography.
http://www.thephotoforum.com/forum/articles-interest/136541-astrophotography-how-guide-part-i.html

http://www.thephotoforum.com/forum/articles-interest/136544-astrophotography-how-guide-part-ii.html

http://www.thephotoforum.com/forum/articles-interest/136545-astrophotography-how-guide-part-iii.html

http://www.thephotoforum.com/forum/articles-interest/136546-astrophotography-how-guide-part-iv.html

 

[astroNikon]

But the Dobson, at least the one I nearly bought a few months ago, isn't the greatest platform for astrophotography but it still works fine. You just have to learn some things .. 2 posts down.

I nearly bought a 10 inch meade dobson a few months ago for more deep space viewing. Such as this
Meade 10 Inch LightBridge Truss-Tube Dobsonian Telescope

The main issue, is that is it totally manual /muscle adjustment. Meaning you use your physical self to adjust things. And there are two main issues with that. Yes the newer ones are manually gear driven vs older ones I looked at.
1 - you don't want the camera falling off because all that holds it normally is one set screw
2 - dobsons are designed for portability and high light gathering and normally don't have tracking systems.

and considering I was already invested in a Meade 125 telescope I skipped the Dobson.

But the pieces you need are:

a T-adapter is two things. a "ring" for your camera mount called a
#1 T-adapter, such as
Amazon.com: Adorama T-Mount Adapter for Nikon AI & Autofocus: Electronics

# 2 and either a "tube" T-mount for rear prime focus (which Dobsons normally DO NOT have)
Meade #64 T-Adapter for ETX-90/105/125 Telescopes - Camera Attachment - Telescope Accessories at Telescopes

OR (preferred)
# 2 or for the Dobson an eyepiece camera adapter
(A) such as this simple model
Meade 1.25in Basic Camera Adapter FREE S&H 7356. Meade Telescope Accessories.

(B) or a more complex model that allows you to adjust focus
Meade Variable Projection Camera Adapter (1.25") 07361 FREE S&H 07361. Meade Telescope Accessories.

On the A & B you can add an eyepiece into the device for magnification.
OR
you can unscrew the top part and use it as a prime focus adapter (the part that can accommodate and eyepiece can be screwed off)

There are also more complex and expensive eyepiece solutions such as using a ClickStop Zoom eyepiece
http://www.astrophotography-tonight.com/wp-content/uploads/2011/10/dslr-reflex.jpg

But, as mentioned with the Dobson I was afraid of readjustments would knock the camere off of the eyepiece location. As the eyepiece location is designed for ease of viewing and not a heavy camera mounted to it. Keeping it as low as possible without all the extenders is key for the Dobson, if you ask me.

I opted against a dobson but I was thinking of taking at most 30 second exposures and stacking each one. I have yet to get into stacking though.

 

[astroNikon]

Now Visually

NOTE: these are 1.25inch pieces. The Dobson's i've looked at are 2inch, but you can get 1.25 inch adapters (which I what I was looking at wince I already owned everything needed at 1.25").

1 - (left) Prism, Someone mentions a prism above but I would stay away from it for Dobson use as it take the camera further away from the body and with a Dobson I'd be worried that it would swivel and fall out.
2 - (middle back) T-mount which can unscrew into a couple pieces for different telescopes with rear mount capabilities which the Dobson I was looking at did not have,
3 - adjustable eyepiece adapter (right)
4 - T- adapter (middle bottom).


The eyepiece adapter (left) with the prime focus part unscrewed from it (middle) and the T adapter (right)


The prime focus of the eyepiece adapter with the T adapter screwed onto it


The eyepiece section of a telescope - Meade 125 etx - the adapter is next to the telescope's eye piece hole.


T adapter and prime focus part into the telescope



A Nikon and the Tmount/eyepiece adapter


The Camera with the T-Mount and the prime focus of the eyepiece adapter. make sure you turn off AF on the camera. This adapter can bend the pin dependent upon your camera.


The camera, on the adapter on top of a Meade 125etx which uses the telescopes's Mirror (same as eyepieces) to direct the image to the camera


NOTE: even with the one set screw on tight (and not too tight to strip) the camera can still swivel when the scope point far up.
Also the weight may affect tracking capabilities especially when it is off the back of my scope. Then you get into counter weights, etc etc etc
With tracking motors you want to make sure they have metal gears (not plastic) so they don't get stripped from extra weight.

 

[astroNikon]

Now, Dobson's are perfectly fine actually. You just have to learn how to use them differently.

in this thread the writer uses a Dobson for moon photos.
Many times I take photos without my tracking system turned on. You just have to learn how.

Astrophotography on a Budget | AstroPhotography Tonight

As mentioned earlier, the main item I had with the dobson is the height of the camera and worrying about it falling out if I adjust it around. Plus it's still a 2000mm just with more light gathering as my current telescope. I'm leaning now on an older LX10 scope or LX90s now.

 

[KmH]

Compared to the planets and deep space objects the Moon is very close, very big, and very bright, and because short exposure times can be used does not require more than just resting the camera on a bean bag or other solid support to shoot.

As mentioned to get planet details and use the long exposures needed for shooting diffuse deep sky objects the camera/telescope has to move to counter act Earths's rotation on it's axis.

Dobsonian telescopes generally are on a simple to make alt-azimuth mount which has to be driven in both the altitude and azimuth axis to counter act Earth's rotation. Controlling the movement of 2 axis accurately at the same time requires computer controls.
There are dobsonian telescope mounts that are motor driven in both axis. No doubt they cost more than hand driven alt-azimuth mounts.

Most other reflecting and refracting telescopes are mounted on a equatorial mount that has had one axis lined up with Earths rotational axis so the mount only has to be driven in 1 axis to counter act Earths's rotation.
Because of the way an equatorial mount works a counter balance is usually need to balance the weight of the telescope that by necessity cannot be on the axis aligned with the Earths rotational axis.
In other words equatorial mounts tend to be more complex and more expensive than alt-azimuth mounts.

As a point of reference, back in the day when I did astrophotography on film using an 8 inch Schmidt camera, an exposure of M31 (the Andromeda galaxy) took about 45 minutes. Being about 4.4 million light years away M31 is pretty faint, thought it's core can be seen by the unaided human eye unless there is a fair amount of light pollution.
M31 is quite big and if it were bright enough we could see all of it with out eye, it is a bit more than 6 Moon diameters wide in the sky.

Schmidt camera - Wikipedia, the free encyclopedia