First shot from a dark location, 50D

[jmx]

Got my 50D only a month or two ago along with a telescope and I have to say, I'm hooked. I had no idea you could photograph galaxies from earth...for some reason I'd assumed all the shots I see in books and TV came from satellites. Boy was I wrong. :oops:

Anyway, I've got a few to share that I'm happy with, being a beginner and all.

Andromeda:
http://jmx.ls1howto.com/pics/thumbs/m31.jpg
Fullsize:
http://jmx.ls1howto.com/pics/m31.jpg



Shot with 7 galaxies:
http://jmx.ls1howto.com/pics/thumbs/m51_widefield.jpg
Fullsize (and I labelled them since they are hard to see):
http://jmx.ls1howto.com/pics/m51_widefield_labeled.jpg

There's more on my site, along with the full specs of focal length and whatnot. These are all 5-15 minute capture lengths, I never spent any significant time on one subject since I was just excited to be seeing anything at all. :)

The equipment was:
Unmodified 50D
Celestron C6N (basically equivalent to a 750mm lens)
CG5 equatorial mount

Jon
http://jmx.ls1howto.com

[Celestron]

You did very good Jon ! Question on the CN6 . Is it a SN ?? Meaning SchmidtNewton ?

[jmx]

It is just a plain old Newtonian. The coma on the edges gets to be pretty annoying.

[bht-kevin]

So cool. You are going to make me buy a telescope/equatorial mount.

[troypiggo]

Very nice! Really like them both. I'm very keen to attempt M31 when the time of year is right for us down under. Think Sept-Dec best.

[Nighthound]

Outstanding images Jon. Maybe the best "beginner" deep sky shots I've seen.

These are stacks of five 15-minute exposures? How are you guiding these long exposures?

You might consider the Alpine Asto MPCC(multi-purpose coma corrector). I use one with my 8" Newt and it works extremely well. I'm not sure if there would be one available for your 6" model, but worth a look.

Great work.

[HaroldC3]

John, did you guide those with something?

I have the exact same scope with an EQ mount but have no way to guide it at the moment.

Curious how you got some long exposures.

Thanks!

[ebann]

I had the same CN6 on an Orion Astroview mount. I sold the CN6 and kept the mount for my TeleVue Ranger. The CN6 was a pretty decent tube.

[jmx]

These shots are totally unguided, and thus the result of shorter exposure shots stacked together.

The andromeda shot is 7 x 30 second exposures, or 3.5min total @ ISO1600 f/5 750mm

The m51 shot is 13x60sec, or 780 sec total @ ISO1600 f/5 750mm.

As you notice, I stacked strange numbers like "7" and "13"...that is because only 7 of 10 andromeda shots were worth while due to periodic error and i suppose lack of guiding (I honestly don't know if guiding helps fix the periodic error or not, I just know I get lots of ruined shots), and only 13 or 20 m51 shots were usable due to the same problem.

I used one of those canon timer devices to take all my shots, and I also used the in-camera dark frame subtraction, so every single shot has a dark frame taken right after it and subtracted out automatically. While this doubled my exposure times, I felt it was one less thing i could screw up...plus the temperatures were dropping fast at night and I assumed noise would be changing every hour.

[jmx]

You might consider the Alpine Asto MPCC(multi-purpose coma corrector). I use one with my 8" Newt and it works extremely well. I'm not sure if there would be one available for your 6" model, but worth a look.


It seems as if there are no correctors at all available to me, so I must either step up to an 8" newtonian, or modify mine to have a 2" focuser. This telescope setup really is about as cheap as it gets, so I suppose I should be happy with the results I have for now. On the m51 shot I did end up cropping out the outer 20% of the shot because it was simply too distorted....and this is on a 1.6x crop sensor!

[Nighthound]

That's too bad but definitely not worth sweating those details now. You've got fantastic results here, I'm looking forward to seeing your progress.

Guiding will not cure periodic error. In fact it can make the guiding software struggle if it's really bad. Many of the mid range mounts have periodic error correction built into their guiding systems. It allows you to train the guide system to adjust the tracking rate when the imperfections in the gears cycle by. Unfortunately running these recorded corrections or training sessions while autoguiding can work against the guider and cause accuracy issues of its own.

In my case I upgraded my worm gears and lubrication and that helped a lot. With some trial and error I was able to adjust my gears to operate pretty well. I use a Losmandy G-11. It's not the best or the worst mount for the job but it required quite a bit of tinkering to get it where it is today. Now I just need a break with the weather so I can dust it off and use it.

Aside from all the mechanical aspect, balance and polar alignment fine tuning(drift alignment) were my greatest leaps forward in long exposure work. I still do a quick drift align when autoguiding just to help the software work a bit less.

[RBChallenger]

It seems as if there are no correctors at all available to me, so I must either step up to an 8" newtonian, or modify mine to have a 2" focuser. This telescope setup really is about as cheap as it gets, so I suppose I should be happy with the results I have for now. On the m51 shot I did end up cropping out the outer 20% of the shot because it was simply too distorted....and this is on a 1.6x crop sensor!

would you mind sending me the links to where I could buy the setup you have and have it work with my 500d. I'd be ever so grateful as I know nada about this but am trying to learn more. Thanks!

[jmx]

Guiding will not cure periodic error.

darn, I was thinking that was the main point of it. I only slightly drift in my photos, but I suppose that too limits me to about 60 second exposures, and also keeps me from doing nice shots with my 2.5x powermate.

Aside from all the mechanical aspect, balance and polar alignment fine tuning(drift alignment) were my greatest leaps forward in long exposure work. I still do a quick drift align when autoguiding just to help the software work a bit less.

I suppose I should learn to do a drift alignment, however at home it is impossible due to the fact that I can only see about 10% of the night sky between the trees and the buildings (I'm on the bottom floor of a condo building, and my porch has a roof). I am surprised to hear about balance being an issue...I've been balancing my setup when I first start during the night and I balance it with an eyepiece in the focuser. Later after looking at things for a while, I load on my 50D and i do NOT rebalance. I guess the extra 1-2lbs hanging off the focuser will make a pretty big difference in tracking?

[jmx]

would you mind sending me the links to where I could buy the setup you have and have it work with my 500d. I'd be ever so grateful as I know nada about this but am trying to learn more. Thanks!

Yeah, it's confusing at first with all the options. The gist of it is, you need a telescope of course, an equatorial mount, and some way to hook your camera up to the telescopes focuser tube.

So, what I got was this:
http://www.celestron.com/c3/product.php?CatID=11&ProdID=55

It's a 6" newtonian reflector telescope, on a tracking equatorial mount. The 8" one is about $200 more, and might be what I'd recommend just because it has a bigger focuser on it (2" instead of 1.25"), which will allow you to use more accessories later on down the line.

Now, you need the way to use the telescope as a fake camera lens, and you do that by using a T-ring.
http://www.optcorp.com/product.aspx?pid=802&kw=canon%20ring&st=2

The t-ring connects right to the front of your camera exactly like a lens does, and the other side of the ring is threaded and you can screw it right into the focuser of the C6N telescope I linked above (NOTE: most telescopes don't let you do that, and require a "t-adapter" which is cheap).

You also need a little power supply thingy that all the telescope stores sell for about $50...its a big battery with a cigarette lighter port on it so you can power your telescope.

That is the minimum to be able to take the photos you see on my site. I also made something called a bahtinov mask out of a thick sheet of black plastic and a razor blade which helps me focus perfectly on targets, but you can make one of those once you actually get a scope and figure out why you need it ;)

[jmx]

Btw, here's a moon shot with the same setup...

http://jmx.ls1howto.com/pics/thumbs/moon02.jpg
Fullsize: http://jmx.ls1howto.com/pics/moon02.jpg

[RBChallenger]

Thanks, I really appreciate the help with the jumping in point!

Out of curiousity, will the 8" one track objects automagically for you?

[jmx]

Anything on a "goto" mount will find stuff in the sky for you by pushing some buttons on the hand held computer and it will track it. The "equatorial" mounts have the added side effect of keeping the stars from rotating in your photos, which is what you want for photography.

[Adrena1in]

Blimey, those don't look like beginner's shots to me! Very well done, especially M51, which is quite a tricky target. I also look forward to seeing your progress.

[Nighthound]

darn, I was thinking that was the main point of it. I only slightly drift in my photos, but I suppose that too limits me to about 60 second exposures, and also keeps me from doing nice shots with my 2.5x powermate.



I suppose I should learn to do a drift alignment, however at home it is impossible due to the fact that I can only see about 10% of the night sky between the trees and the buildings (I'm on the bottom floor of a condo building, and my porch has a roof). I am surprised to hear about balance being an issue...I've been balancing my setup when I first start during the night and I balance it with an eyepiece in the focuser. Later after looking at things for a while, I load on my 50D and i do NOT rebalance. I guess the extra 1-2lbs hanging off the focuser will make a pretty big difference in tracking?

Balance is critical for deep-sky imaging. You should balance with all your gear just as it will be during exposures. You should also balance with a tiny bit of bias toward the east. In other words balance with your counterweight on the east side and allow it to be just a touch off perfect balance toward the east side. What this does is apply a very slight amount of resistance where the gears mesh. If you are perfect balanced the gears will not have this slight resistance and the tolerance gap between the gears will become a teetering (back and forth) point while the mount is tracking which can look like periodic error when in fact it is just the gears loosing some contact as they are turning. The less precision made the gears, the more this becomes an issue. I mount my scopes on a side by side plate and perfect balance. I add bias on the counterweight shaft using a small ankle weight. The principle is the same as I described but it allows me to slightly adjust the amount of bias weight as the scope moves into different positions while tracking.

As I stated this is a critical part of set up. There are many check points in this imaging process that have to be addressed to help get the most out of your shoot time and the gear you use. Equipment can be limiting, especially at lower price points but set up and technique is vital to get good results regardless of the gear we choose.

[Bill Boehme]

Great images and lots of useful information in this thread. Does anyone know if Bahtinov mask would be useful in focusing with a telephoto lens?

[Nighthound]

Great images and lots of useful information in this thread. Does anyone know if Bahtinov mask would be useful in focusing with a telephoto lens?

That's an interesting question Bill. I haven't tried one with my Sky 90 which has a FL of 407mm with the reducer. That would be near your 400L. I would think as long as you focus on a bright enough star and can enlarge it enough to evaluate the mask diffraction spikes it should work as it should with a refractor. Speculation at this point, I hope others who have tried will chime in.

[jmx]

Thanks for the info NightHound. I'll pay more attention to the balance next time.

Great images and lots of useful information in this thread. Does anyone know if Bahtinov mask would be useful in focusing with a telephoto lens?

Uh, I didn't realize bahtinov masks were useful for anything else! I focus my camera/telescope setup with one every single time...it simply seems impossible to get perfect focus any other way for these shots. Again I'm a beginner so maybe there's some other trick to it, but I was consistently blurry until I made a mask for my scope.

[Bill Boehme]

I have been using my 400/5.6L with both of my teleconveters stacked together (1.4X and 2X) to get 1120 mm FL and it works well when I get the focus right, but it sure is difficult without live view. I do need to get a right angle adapter for my camera which would also help a bit with neck strain and image size.

[Nighthound]

You're welcome Jon, always glad to help. Your Moon shot is fantastic.


I have been using my 400/4L with both of my teleconveters stacked together (1.4X and 2X) to get 1120 mm FL and it works well when I get the focus right, but it sure is difficult without live view. I do need to get a right angle adapter for my camera which would also help a bit with neck strain and image size.

That's great that you can stack them and get good results Bill, I haven't tried that yet with the 500. I have an Anglefinder C and it does help with focus on brighter objects like the Moon, it can be a bit of a challenge on dimmer things since the added glass diminishes light some. You'll enjoy the ease of view with one for sure, I like how it can rotate to any angle you might need. With my long tube refractor I used to lay on the ground at times to focus and frame objects, a pain in multiple places.

[Bill Boehme]

I just found the answer on Cloudy Nights while looking for a template for a Bahtinov mask -- it works just as well with a camera lens as it does with a telescope.

[jmx]

Oh, I thought I answered your question above. <shrug>

I made mine out of a $1.99 black placemat from IKEA. Best $1.99 I've ever spent.

[Bill Boehme]

I suppose that I did not interpret your response correctly -- I assumed that your reference to "camera/telescope setup" meant a camera coupled to a telescope as opposed to a telephoto lens.

[Jon Foster]

Interesting thread...

Jon.

[VIGER]

Hi

I am late but just to say that you are on a roll man ....
Cheers

[ejicon]

You website is primo nico... I like how you give a nice little story behind all your photos and trips... keep it up. What kind of telescope are you using? I'd like to get into this as well... one day.

[jmx]

ejicon, thanks. I've only just started the code for the website, so its still evolving. The code/design was done a week ago or so, and I've not written all the stories yet. :) I have months of photos to upload as well. So much to do!

Anyway, I suppose I should update this thread with some other images taken with the same "cheap" telescope setup. The next month after the original photos in this thread, I took these guys:
http://jmx.ls1howto.com/pics/thumbs/m8.jpg
Fullsize: http://jmx.ls1howto.com/pics/m8.jpg

And this was with the 100mm macro f/2.8 lens (the fullsize is the only one worth looking at, but here's a thumbnail anyway):
http://jmx.ls1howto.com/pics/thumbs240/antares.jpg
Fullsize: http://jmx.ls1howto.com/pics/antares.jpg

And the month after I took this one (retake of andromeda):
http://jmx.ls1howto.com/pics/thumbs240/m31_072009.jpg
Fullsize: http://jmx.ls1howto.com/pics/m31_072009.jpg


So those are the "gems" from my first 3 months of learning astrophotography. I've just in the last week got a new mount and a new scope, so hopefully I can address some of the issues I've been having. I'll post some new stuff very soon with the new setup. (PS, the old setup is for sale if you're in SoCal)