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Lomitus
2004-Feb-22, 06:47 AM
Howdy Folks!

Again (and again and again...), thanks to everyone who's been so helpful here getting me started with everything!

Well, we're supposed to have a mostly clear night tomorrow night so I'm getting everything ready! I've been goin thru the stuff on the new scope...I think I got all the basics for the Autostar figured out (fingers crossed), etc.. I've been readin up on stuff and am even starting to plan my next bunch of purchases...a plossl lens (or two), a moon filter, and eventually a t-tod connector for the 35mm...which brings me to my question(s)...

After my first views of Jupiter and of Saturn's rings this last week, again I'm hooked! I just gotta get some of this stuff down on film (or .jpg). I dug out my cameras today...a rather old Canon FTb and my Polaroid PDC700 digital. Now, I fiddled and fussed with the digital today, and I am going to give it a try tomorrow night, but I'm not counting on any kind of success with it as its a -very- limited camera...even as far as digitals go. What I'm counting on here is the ol' Canon. She's an oldie, but a sweetie and over all is in very good shape. I have used this camera quite a bit over the years and have always gotten good pic's with her. I had put her away a few years ago...while shooting pics of my wifes college grad, it was an indoor cerimony, very hot and humid and the shutter had started sticking. About the same time, I had gotten this Polaroid digital, so...the Canon got stowed for a while. I broke her out this afternoon, took everything apart and cleaned it all (not to mention refamiliarized myself with everthing!) and she's ready to go...more or less...here's the questions...

Now I realize that there is no hard answer to this and that its all dependent on my sky conditions, etc... I also know that I"m gonna have to go out and get a shutter release cable for anything serious as well as a t-adaptor when I got to mount it on the scope. With all that said, the camera has a f/28~80mm zoom lense (I know zoom ain't recommended, but its all I have and it is a high quality lens) and I have an aperature that goes down to 3.5. My first question is; will I actually be able to get anything with this setup without the shutter cable and if so, what speed film should I use? Also, any recommendations on film brand would be helpful...I know I've seen one of the Fuji types recommended somewhere.

Question #2...
Once I get that shutter release cable, again what film speeds are recommended and how long I should I leave the sutter released for some basic constillation shots? Again, I don't have the camera mounted to the scope yet...either on top or t-adapter...basic tripod setup. And again, I realize there is no hard/fast answer to this due to light conditions...just looking for some general guidlines and a good starting point.

I am planning on going to a local astronomy club meeting week after next and will be asking -tons- of questions about scopes, astronomy and astrophotography there, but call me an oportunist...I'm tryin to get a jump on things here :-).

Question #3...
Ok, this may be better aimed at the Meade forum I found, but gonna ask it here too as you good folks ain't steered me wrong yet! Again, this camera is an older Canon SLR with a rather sizeable lense and I'd have to estimate the total weight on this sucker as at least 3 or 4 lbs...its pretty heavy. When I do go to strap this thing to my new scope (again a Meade DS 2114), is this extra weight going to cause a problem for the motors...both short term tracking and long term pre-mature wear? Seems like a legit concern.

Question #4
I know I'm getting -way- ahead of myself here...if ya'll haven't guessed by now, its my nature :-) When I get the T-adapter to plug the camera right into the scope, again I'm worried about the weight issue. It doesn't seem practical to have the camera mounted to my tripod and connected to a moving (albiet slowly moving when its tracking) telescope. I'm -assuming- that when I get the t-adapter to plug the camera into the scope, that I should be getting some kind of mounting strap or something to support the camera?


I know after I've been to a couple of these local astronomy meetings I'll have a better understanding of all this stuff and afterwards, ya'll will probably never have to listen to me buggin ya with stupid questions again! (LOL!!!) On the other hand, even though I've only used this scope twice so far (and I honestly do love it!), I'm already planning to build one of my own sometime later this year! While a nice Dob would certainly be the easiest, I'm a rather ambitious person and I keep drooling over those 12" and 14" Schmidt-Cassegrain's I keep seeing in the books, mags and on the web...I already have a few ideas about building one :-)

Anyways, thats if for the moment...my eyes are tryin to force themselves shut, so I best get some sleep. Thanks again everyone!

Bright Blessings & Gentle Breezes,
Jim

Lomitus
2004-Feb-22, 10:16 PM
Okies...I got the camera ready to go (I hope). I got some 800 speed Fuji Superia Extra film. What I need to know is aproximate exposure times. Again the Camera is a Canon FTb and the lens is a f28~80mm and it will be tripod mounted tonight. I know to go with the widest aperature (or close at least to avoid aberations on the sides of the image). I'm sure the focus will probably be set to infinity. Whats a good time range to start with for keeping the shutter open? 10 sec's? 30 sec's? a minute? 5 minutes? Again at the moment, I'm gonna be just looking to shoot some stars/constillations...nothing serious at this point...just "gettin my feet wet" so to speak :-).

Thanks to anyone that can help!

BB's,
Jim

Kaptain K
2004-Feb-23, 07:04 AM
One minute exposures should give you nice pictures of constellations. Longer (15 minutes to 2-3 hours) will give you nice star trails, especially if your camera is pointed north.

I hate to be the bearer of bad news, but you will not be able to get long exposures using your telescope. Even though it follows the stars, since it is an alt-azimuth mount (instead of equatorial), the star in the center of the field will be sharp, but the field will rotate as the scope moves. The stars that are not centered will be short arcs.

JohnW
2004-Feb-23, 05:11 PM
A couple more suggestions:

1. Your tripod is going to vibrate when you open the shutter. To reduce the effects of this, put something dark and opaque in front of the lens for a few seconds after opening the shutter, and put it back just before it closes.

2. If you're not doing your own developing, tell the developer that you've been photographing stars. Otherwise, they might just see black, think it's an unexposed roll, and junk it.

Lomitus
2004-Feb-23, 06:27 PM
Thanks Guys,
I'll probably be heading up to the photo store tomorrow to get a shutter release cable and I'll check on getting a lens cap for the tripod vibration thing (they have a large box of misc lens caps...something should fit). I'm plannin on going thru a local place for the photo development, supposedly they have experience with astrophotography developing. I also know about asking them to -not- cut the negatives :-) I've done a -little- research and plan to do even more before tomorrow evening.

I didn't get a chance to shoot anything last night...mother nature just didn't cooperate...Tuesday is thus far looking hopeful, so we'll see how it goes!

I'll probably try a couple of different exposure times (making sure I keep notes on which is which) starting with one minute and working my way up from there.

Now, thru you guys and thru another forum, its become pretty clear that other then pics of the moon, I shouldn't expect too much by using a t-connector from the camera to the scope as it appears the motor just won't be strong enough, I do however have a couple of related questions...

For shooting stuff like constillations without star trails (cool effect, but going to be trying to get some "straight" shots too), a well balanced "piggy-back" setup seems like it should be less stress on the scopes motors (I will also take a look at some used lenses tomorrow to see if I can lighten the weight a little...I understand that a f/50mm should be a good place to start). Does this sound logical? Obviously using the T-adaptor is going to put all the weight of the camera right up on the front of the scope (again a Meade DS 2114 4.5 reflector", but a balanced piggy-back seems like it might do ok.

Now the other question is I have is in regards to the alt-azi mount versus the eq mounts. I understand the "technical" differences...sort of. I know that the alt-azi is a 2 pivot point mount versus the eq which is a 3 pivot point mount. Now, with that said, if the motor is tracking the stars (assuming that the motor on mine has enough beef with a camera mounted on back to track accurately)...if its tracking the stars, why would the alt-azi still create star trails? Not sure I understand this. If nothing else, this is something I'm gonna want to keep in mind later this year when I start working on telescope #2 :-) Which leads me to my next question...

Ok, this is sort of a very preliminary thing here. Yes, I've only used my new scope twice so far, and I -do- love it and will get a tremendous amount of use out of it, but again, I'm starting to (mentally at least) work out the plans in my head for building a scope later this year. I've looked at a few books and a couple of videos and it looks like the most popular design for the diy'er is the Dobson's. Quick note...one of the videos I have...educational stuff from JPL taped in 1993...has a quick interview John Dobson showin a couple of his home made scopes. He seems like a very kindly old man :-) Not sure if he's still around or not as the vid is over 10 years old and he seemed rather up there in the years in the vid, but he still was impressive to me. Anyways, I guess my question is, how much harder is a Schmidt-Cassagrain design to build as apposed to a Dob? Dobson had his 18" reflector in the video and the thing was just -massive-...you'd really need a trailer and two rather strong friends to help move that kind of beast and I can see where a 12" or 14" Dob wouldn't be that much better. A 12" or 14" Schmidt-Cass on the other hand, while still being sizable, would at least fit in the back of my minivan! Not taking tripods/mounts into consideration for the moment, how much harder (and/or more expensive) is a Schmidt-Cass going to be to build as apposed to a Dob? Again, this is just a preliminary curiousity thing :-).

Okies...I think thats all for now! Found out our local astronomy group has a small/modest observitory in our Metroparks system and the wife and I are heading out there today to make sure we both know where it is and how to get there...not to mention take our dogs out the park and let them run for a while :-).

As always, thanks for your collective wisdom...I'm truly grateful!
Bright Blessings,
Jim

JohnW
2004-Feb-23, 07:22 PM
I'll probably be heading up to the photo store tomorrow to get a shutter release cable and I'll check on getting a lens cap for the tripod vibration thing (they have a large box of misc lens caps...something should fit).

No, not a lens cap. You need something to put in front of the lens without touching it. If you remove a lens cap, that will make things vibrate.

A cable release will help a lot. If you're images are coming out blurry, remember that unless your mount/tripod is very heavy, the shutter itself will cause some vibration. You might still need to cover the lens for a few seconds.

JohnW
2004-Feb-23, 07:29 PM
Now the other question is I have is in regards to the alt-azi mount versus the eq mounts. I understand the "technical" differences...sort of. I know that the alt-azi is a 2 pivot point mount versus the eq which is a 3 pivot point mount. Now, with that said, if the motor is tracking the stars (assuming that the motor on mine has enough beef with a camera mounted on back to track accurately)...if its tracking the stars, why would the alt-azi still create star trails? Not sure I understand this. If nothing else, this is something I'm gonna want to keep in mind later this year when I start working on telescope #2 :-)

They're both 2-pivot designs. The difference is that an equatorial mount has one axisaligned to the celestial pole, so you only need to move on the second axis to track objects across the sky. With an alt-azimuth, you need to move on both axes. This causes star trails off the central axis, because the orientation of the scope changes silightly - objects near the edge of the field will shift position.

Equatorial mounts on prtable tripods do have a third axis, but this is used to align with the celestial pole. Once this is done, that axis is locked and not used while observing.

Kaptain K
2004-Feb-24, 10:46 AM
No, not a lens cap. You need something to put in front of the lens without touching it. If you remove a lens cap, that will make things vibrate.
Some of us "old timers" call this the "hat trick". Put your hat* in front of the scope, open shutter, remove hat,... wait..., put hat in front of scope, close shutter.

* Black cardboard works well.

tngolfplayer
2004-Feb-24, 07:06 PM
As far as your question about the weight of the camera goes, I had problems with a pentax and a meade etx 90 ec. The camera weighed just enough to throw off the tracking motor.