Weasner's Nikon DSLR Astrophotography Discussion Page

ASTROPHOTOGRAPHY WITH THE NIKON DIGITAL SLRs

Last updated: 13 April 2008

This page documents Nikon D70 and other Nikon DSLR camera comments, tips, and photos. Search the site for "nikon dslr" for other items about the Nikon DSLR cameras. Contributions welcome.

Subject:	Piggybacking the D70 
Sent:	Saturday, April 12, 2008 13:01:49
From:	User721401@aol.com (User721401@aol.com)
Congrats on the retirement and move...

 I am slowly settling into my new place and had a thought.  I have an
 older ETX125 and the newer PE model.  If I wanted to piggy back my D70
 to the older model, do I need to do an alignment on it?  All I am
 trying to do is take some long exposures with a 200mm lens of the Orion
 Nebula. I am thinking about polar mounting the older ETX and just using
 it to track while the D70 is mounted to it and taking several
 exposures.

 The other question; What is the best way to figure out how much counter
 weight is needed for the above setup?

 Thank you for your amazing site and sharing your knowledge with all.

Dan
Arlington Heights, IL

Mike here: You don't need to precisely align the camera to the telescope optics. In fact, you can point the camera in one direction and the telescope in another, within reason. I've done long duration exposures with my ETX-90RA (polar mounted) with the D70 piggybacked; you can see more on this on the "My Nikon D70 DSLR" on the Helpful Information: Astrophotography page. As to counterweight, the best way is trial and error.

And:

Thanks for the info...
 
Dan

End of today's update

Subject:	Do you use the autofocus for piggyback Astrophotography?
Sent:	Thursday, January 24, 2008 14:28:53
From:	Sweitzer, Eric (esweitzer@seifert.com)
Hi Mike, sorry to hear about the theft, I am looking to get into
Astrophotography, I have an LXD-75 8"SC and I am looking to get a Nikon
D-40 digital camera to use with it. I am very interested in piggyback
astrophotography and the camera includes a 18-55mm lenses by Nikon. I
am looking to purchase a longer telephoto Lenses with it, but according
to the manufacturer only the Nikon lenses work with auto focus on this
camera and I was looking at an aftermarket 70-300mm Lenses.

So I guess my question is in piggyback Astrophotography do you
autofocus or manual focus?

Thank you for all your work in this field

Eric S Sweitzer

Mike here: The Nikon (and perhaps other cameras as well) use a "sharpness" determination to figure out the infocus setting for its autofocus lens. However, faint points of light like stars do not provide sufficient data for the camera's computer to accurately determine infocus. So the lens focus motor either runs back and forth or just won't run at all. The solution is to focus manually, which is what I do. I pick a bright star and turn the focus ring until the image in the viewfinder is at its smallest and brightness. The "Stiletto Focuser" (which I reviewed on my LXD Site) can be used with a camera lens to determine proper focus.

End of 26 January update

Subject:	ETX-125 EC > Replacement parts. Flood Damage
Sent:	Wednesday, January 9, 2008 04:24:02
From:	Wgc007@aol.com (Wgc007@aol.com)
Let me give you a quick rundown of the issue. I am a 67 year old
disable handicap that was caught up in the Katrina flood in Mobile,
AL. I lost all the accessories for my ETX-125 EC except 45 erecting
prism, one 7-20 mm eyepiece and the scope. (Even lost a brand new
color CCD too +  LapTop) Scope, elec focus and EC unit still works.
I am trying to slowly get back to where I can do some observing.

I need some information: I want to mount a Nikon D80 DSLR to the
1.25" 45 erecting prism, due to having a rigid neck and back I
cannot get into position to view otherwise. This camera body has a
fair weight to it (about 16.5 oz.) so I thought all the mounts
should be screw together. I need some of your expertise on this.
Make, part #'s supplier,  the like. Prime focus to start with I
guess. I was given the following part # by Meade but have no idea
what it looks like. Part # 17356. I know their "T Mount" number is
07378 for it, but a "T-mount is a T-mount. Do you have any other
suggestions for what I'm trying to do.  You're the genius at this
not me. ALL HELP WILL BE APPRECIATED.

Also, I want to use a 12V Gel-Cell battery to drive the scope but
cannot find out what the 12VDC plug size is that fits the scope. OR
whether the center pin is + or - ..

I hate to have to pay $25-30 just to get a cord with a plug on it
and then cut off 20 feet of cord when RadioShack has every plug
known to man for $6ea. Just ordered a new AutoStar 497 to replace
the "wet" one. Money a little tight and We still have to eat first.
LOL

Mike, I'm sorry to hear about your theft. I know it made you sick
when you found out about it. Things like this really make you feel
violated. I will certainly be on the lookout here. Doubt any of it
got to the SouthEast though.

Bill

Mike here: Check out my Nikon D70 page on the Helpful Information: Astrophotography page for all the info you need for connecting and using the D80 with your ETX. See the Power Supplies section on the Helpful Information: Telescope Tech Tips page for info on connecting external power sources.

Go to the October-November 2007 Nikon DSLR Discussion page.

Go to the February-September 2007 Nikon DSLR Discussion page.

Go to the 2006 Nikon D70 Discussion page.

Go to the 2005 Nikon D70 Discussion page.

Go to my Nikon D70 Astrophotography page.

Go back to the Astrophotography Page.

Go back to my ETX Home Page.