# Celestial Lens for Canon



## PackingMyBags (Mar 3, 2010)

So ive been looking at getting into celestial photography. I want to be able to take shots of not only the moon, but planets in our solar system, and possibly some nebula. 

My problem is that i really dont know what lenses to look for in this area. I dont want to spend a whole lot, so a couple $100 wouldnt be bad. I was looking on Amazon and found these mirror lenses:

[ame="http://www.amazon.com/Opteka-Telephoto-Mirror-Digital-Cameras/dp/B0022VFDRK/ref=sr_1_1?ie=UTF8&s=electronics&qid=1267637113&sr=8-1"]Amazon.com: Opteka 500mm f/6.3 Telephoto Mirror Lens for Canon EOS Digital SLR Cameras: Electronics[/ame]

[ame="http://www.amazon.com/Rokinon-1000mm-Mirror-Canon-Mount/dp/B001V97ISG/ref=sr_1_15?ie=UTF8&s=electronics&qid=1267637113&sr=8-15"]Amazon.com: Rokinon 500/1000mm F6.3 Mirror Lens for Canon EOS Mount: Electronics[/ame]

So are any of these a viable option, or do i need to look elsewhere? I want nice images, so if these are crap then ill just be on my way. What do you guys use, or recommend?


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## icassell (Mar 3, 2010)

You should pm Astrostu who is an astronomy grad student and does some beautiful astrophotography, but I would think you would be happier with a small reflecting telescope and an adapter for your camera than with one of those Mirror lenses.


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## PackingMyBags (Mar 3, 2010)

icassell said:


> You should pm Astrostu who is an astronomy grad student and does some beautiful astrophotography, but I would think you would be happier with a small reflecting telescope and an adapter for your camera than with one of those Mirror lenses.



Just sent it thanks! What telescopes do you recommend and which adapters? This is news to me.


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## icassell (Mar 3, 2010)

I don't have the experience -- been many many years since I tried this on a cheapie scope.  He is the guru


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## Tiberius47 (Mar 3, 2010)

On my Deviant Art account, one of my most popular pics is a shot of the stars I got with a 50mm f1.8 lens.

You don't need expensive gear.  Just set up a tripod on a dark night and play around with long exposures.


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## PackingMyBags (Mar 3, 2010)

Tiberius47 said:


> On my Deviant Art account, one of my most popular pics is a shot of the stars I got with a 50mm f1.8 lens.
> 
> You don't need expensive gear.  Just set up a tripod on a dark night and play around with long exposures.



Yea, ive done that, but I kind of want to dig deeper into space to find smaller detail. I mean ive got plenty of shots taken on a tripod with various lenses.

Milkey way with my 17-50mm 2.8






Jupiter 70-300mm






Meteor and moon





Any more advise?


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## Sachphotography (Mar 4, 2010)

I shot astrophotography for a a few years and what your looking for is going to require you to buy some sort of a mount. You need to be able to shoot LOOOOOONNNNNGGGG exposures. Some shots I had nearly 3-4hrs of stacked exposures. I know some guys that had over 30hrs of exposure time. The hardest part is accurately aligning your mount and ensuring accurate periodic error control. A good object to start with would be M31 AKA the Andromeda Galaxy. It is huge and can be seen by the naked eye in dark skies however a decent telescope or telescopic lens would show some good detail. My setup consisted of a Meade LX200 10" Schmidt Reflector. Astrophotography is a deep expensive hole to fall into. I have a friend of mine who live in Conn and has over 100K invested in his equipment. It gets expensive fast!!

I would also research the messier catalog. Some good stuff to photograph that is not hard to find.


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## KmH (Mar 4, 2010)

Sachphotography said:


> ......A good object to start with would be M31 AKA the Andromeda Galaxy. It is huge and can be seen by the naked eye in dark skies.....


 Well, a part of it, the core of the galaxy, is just barely visible to the naked eye as a faint smudge of light. But it _is_ quite a bit bigger, about 5 Moon diameters wide.

When I was doing astrophotography on film with an 8" Schmitt camera years ago M31 a single took at least a 45 minute exposure.

Todays astrophotographers capturing nebula images use specialised cameras that have a cooling system for the image sensor. Cooling the image sensor limits thermal noise in the images that are made. Pro astronomers been using liquid helium to cool their image sensors for a long time. Cameras for Astrophotography | Orion Telescopes

So, for making images of nebulas you need a bunch of aperture. Many recommend at least 12 inches. You also need a motor driven mount eqitorial mount to counteract Earths rotation, and as mentioned the mount needs provision to correct for periodic tracking error in the motor drive for the mount.

Here's a good 11" w/an equitorial mount: Celestron CGEM-1100 Computerized 11in. Cassegrain | Telescope.com

Another popular brand is Meade.


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## icassell (Mar 4, 2010)

Here's the link to Stu's site.  He has a technical section

Stuart's Photography & Astrophotography


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## PackingMyBags (Mar 4, 2010)

Sachphotography said:


> I shot astrophotography for a a few years and what your looking for is going to require you to buy some sort of a mount. You need to be able to shoot LOOOOOONNNNNGGGG exposures. Some shots I had nearly 3-4hrs of stacked exposures. I know some guys that had over 30hrs of exposure time. The hardest part is accurately aligning your mount and ensuring accurate periodic error control. A good object to start with would be M31 AKA the Andromeda Galaxy. It is huge and can be seen by the naked eye in dark skies however a decent telescope or telescopic lens would show some good detail. My setup consisted of a Meade LX200 10&quot; Schmidt Reflector. Astrophotography is a deep expensive hole to fall into. I have a friend of mine who live in Conn and has over 100K invested in his equipment. It gets expensive fast!!
> 
> I would also research the messier catalog. Some good stuff to photograph that is not hard to find.



Thanks for the post. Yea, trying to stay away from a tracking mount and all the 100k price tag. I guess im just wondering what i can attach to my camera for 30 sec exposures with the max zoom availible. I realize that over 30 sec requires a mount that tracks with the stars.  I would love to someday spend that $ on that gear, but for now i just dont have that kind of money. What do you suggest in the meantime?  BTW Messier...


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## Soocom1 (Mar 4, 2010)

Having shot for 30 sec. exposures with my 1Ds and a Manfroto tripod....
Ide opt for a tracking mount of some kind off of a Mead or Bushnell system for around US $250-500. . Granted they are not high end units like the Mead Max tracker (US $23,300) but its better than nothing. Noise is also a problem so shoot low ISO's. Also, if you have rural areas to go to, thats even better.


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## KmH (Mar 4, 2010)

Charles Messier was a comet hunter. (Messy-ya (long a), like French)

As he scanned the skies and came across faint fuzzy things that looked like comets, but weren't, he made a list of where they were and he numbered them. (Messier Numbers: M1, M2, M3, ....)

The Andromeda galaxy, M31, is #31 on his list. The list has 103 objects on it.

Often, a goal for an amateur astronomer is to look at each of the 103 Messier objects in a single night at the telescope.


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## the iconic image (Mar 4, 2010)

Go to my blog somewhere near the top is a shot of the moon a week or so ago. You tell me what lens and settings you THINK I shot it with.

the Iconic Image


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## astrostu (Mar 4, 2010)

I'll respond here rather than to your PM.  I do not think you'll be happy with a longer but cheap mirror-type camera lens.  In order to capture most planets and deep-sky objects, you will need a rather significant telescope that will give you a field of view no larger than around half a degree (somewhere around 2000 mm in focal length).  For something like that, you'll need a rather large diameter so that the aperture isn't something like _f_/64 or bigger.  And then you'd need a mount that rotates with the sky so that you can taken an exposure longer than a second or so with that focal length.

An alternative is a good-quality telephoto lens like something between 200 and 400 mm and possibly with a 2x extender.  You'll still need to have a clockdrive mount to track the sky so that you can take longer exposures unless you take hundreds of photographs at higher ISO and average them together.  Which is actually what you should do with planets - the best photos of planets these days are taken by people using webcamps.


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## PackingMyBags (Mar 4, 2010)

Soocom1 said:


> Having shot for 30 sec. exposures with my 1Ds and a Manfroto tripod....
> Ide opt for a tracking mount of some kind off of a Mead or Bushnell system for around US $250-500. . Granted they are not high end units like the Mead Max tracker (US $23,300) but its better than nothing. Noise is also a problem so shoot low ISO's. Also, if you have rural areas to go to, thats even better.



What are the models of the Mead and Bushnell?

I wonder how the 5dmkII handles deep space shots with its high ISO capabilities. Im sure it can grab more light, but does it also throw off electrons into the sensor creating noise? Anyone know?



the iconic image said:


> Go to my blog somewhere near the top is a shot of the moon a week or so ago. You tell me what lens and settings you THINK I shot it with.
> 
> the Iconic Image


Camera Maker: Canon
Camera Model: Canon EOS 5D Mark II
Image Date: 2010:02:27 23:34:20
Focal Length: 280.0mm
Aperture: f/4.0
Exposure Time: 0.017 s (1/60)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Manual
White Balance: Auto
Flash Fired: No
Copyright: Copyright: mike zukerman


Im going to guess a Canon 75-300 lens, or something similar. BTW how does your camera do with higher iso speeds and deep space photography? Try it out yet?



astrostu said:


> I'll respond here rather than to your PM.  I do not think you'll be happy with a longer but cheap mirror-type camera lens.  In order to capture most planets and deep-sky objects, you will need a rather significant telescope that will give you a field of view no larger than around half a degree (somewhere around 2000 mm in focal length).  For something like that, you'll need a rather large diameter so that the aperture isn't something like _f_/64 or bigger.  And then you'd need a mount that rotates with the sky so that you can taken an exposure longer than a second or so with that focal length.
> 
> An alternative is a good-quality telephoto lens like something between 200 and 400 mm and possibly with a 2x extender.  You'll still need to have a clockdrive mount to track the sky so that you can take longer exposures unless you take hundreds of photographs at higher ISO and average them together.  Which is actually what you should do with planets - the best photos of planets these days are taken by people using webcamps.



Thanks for the post. So the mirror is out? Are Telescopes that allow you to attach your camera out as well? I was actually looking at a Sigma the other day. It was a 150-500 i believe and not too expensive. Sound good?

The mount sounds really good and all, but the price for a good one is just not in my budget. I just wish i could build an observatory in my back yard. :er:


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## astrostu (Mar 5, 2010)

PackingMyBags said:


> astrostu said:
> 
> 
> > I'll respond here rather than to your PM.  I do not think you'll be happy with a longer but cheap mirror-type camera lens.  In order to capture most planets and deep-sky objects, you will need a rather significant telescope that will give you a field of view no larger than around half a degree (somewhere around 2000 mm in focal length).  For something like that, you'll need a rather large diameter so that the aperture isn't something like _f_/64 or bigger.  And then you'd need a mount that rotates with the sky so that you can taken an exposure longer than a second or so with that focal length.
> ...



To be perfectly honest I didn't look at the links to the lenses you were pointing at, but just from some that I've looked at in the past, they seem to be cheap telescope substitutes.  And just from experience, going the cheap way will not make you happy with the results.  I have no experience with the specific lenses that you are looking at, but keep in mind that astrophotography is one of the most demanding forms of photography on your equipment -- even my L-quality lenses show some significant issues that have to be corrected for by other methods (when possible).

Any telescope that you would be looking at would allow you to attach a camera to it.  You would need a T-ring and a T-mount (these things are like $20).  A T-ring is custom to your camera on one end and a universal thread on the other.  The T-mount is custom to your telescope - either 1.25" or 2" diameter usually - and converts to a universal thread on the other.  Thread one to the other and you have your camera on your telescope.

Not getting some type of motorized mount is kinda out of the question for this sort of thing.  Unless you want to be taking dozens to hundreds of images and doing a lot of post-processing, you MUST compensate for Earth's rotation.  These days, almost all telescopes sold come with a motorized mount that should be reasonably accurate.  I haven't seen periodic errors listed for most, which generally isn't a good sign, but otherwise I do not have an informed opinion to make in regards to them.


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## Sachphotography (Mar 5, 2010)

Regardless of the camera used. You are going to have noise. The way you get rid of a lot of in camera noise is by taking a dark frame with the lens cap on and using it to subtract that "fake" star noise. Most astrophotography programs have this as a preset. truthfully you can get a telescope with a trackable mount for not to much. You could use the ETX line of telescope and get a decent mirror telescope "Maksutov Cassegrain" with a fully motorized mount and a goto "autofinder" function built in. for under 1000. It would be good for planets but Deep space object would take a little longer. You can however mount your camera and lens on the top. Just make sure if you use a fork mount, balance it perfectly to not destroy the motors.


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