Weasner's Astrophotography Tips Page

ASTROPHOTOGRAPHY - TIPS

Last updated: 31 December 2005

This page documents astrophotography comments, tips, and photos. Contributions welcome. Be certain to see the other articles on the main Astrophotography page.

Subject:	Meade DSI
Sent:	Saturday, December 31, 2005 09:41:50
From:	Ed Williams (hotstrings1@knology.net)
I am still learning a lot from you site it has been very helpful.

My question is __ I have a cannon rebel  and a T connector to go through
the scope from the back.

If I want to take deep sky photos would I be better of with -- ! a
camera holder using it with say astro stack or ---2 buying a Meade DSI
imager? Which would be the easiest to use also?

Thanks in advance,

Ed Williams

Mike here: You didn't say what telescope you have but using the DSI, while there is a learning curve, will get you better images faster of most DSOs. On the other hand, with some work you can get images of many DSOs with just about any digital camera that supports long duration exposures and/or has a removable lens.

And:

I.m sorry about that. I have a etx 90m and  a etx125ec.
I hope that helps.
Ed

Mike here: The only problems with mounting a camera on the rear port of the ETX models is the weight throwing the system out of balance and the movement interference in some orientations from the base and fork arms.

Subject:	Astrophotography using astrostack?
Sent:	Thursday, December 29, 2005 16:49:15
From:	david smoyer (david_smoyer@yahoo.com)
I've been surfing through your various
websites for a few months now, and I wanted to say thanks for doing such
a great job on giving ametuer astro buffs cool things to look at and
read.

So, I've got a Meade ETX 90, and I'm trying to get into some entry level
astrophotography.  I download Astrostack, and tried running thru the
sample/tutorial.  It just plain doesn't seem to load the sample images
(a series of Jupiter shots, it looks like).  I'm following all the notes
for the tutorial, but no luck.  Is there something I'm missing?  Is
there any advice or helpful hints you can spare to assist a newbie on
this?  I'd appreciate anything.

Thanks much!

Cheers,
Dave

Mike here: I don't use Astrostack so can't answer directly. (I use Lynkeos for Mac OS X.) You might try Registax; there is a tutorial on it on the Helpful Information: Astrophotography page.

Subject:	recent gift ETX-70AT
Sent:	Monday, December 26, 2005 13:19:58
From:	barrett johnson (cbjohnson81@hotmail.com)
I had recently received the 70AT, and i have my doubts on its
performace.  I have never attemped astrophotography, but i am a
professional photographer in normal conditions.

Please advise as to whether i should keep this unit or upgrade.  I am
looking to get as much clarity and magnification as possible with a very
large Nikon SLR.

I havent been able to find a buyers guide on your website.  Thanks for
your help.

Barrett Johnson
www.cbarrettjohnson.com

Mike here: What you have with the ETX-70 is a 350mm telephoto lens. I doubt that will meet your expectations. You likely want a much larger telescope (both aperture and mount). If you are really going to get into astrophotography, get as much aperture and mount as you can afford. As to what the ETX-70 and other ETX models can do, see the various astrophotography pages on my ETX Site. For what some larger aperture telescopes can do, see my LXD55 site (www.weasner.com/lxd).

Subject:	To make a piggyback adapter
Sent:	Monday, December 12, 2005 06:07:25
From:	Mauricio Lpez (mlopez@constructorabolivar.com)
In order to do a piggyback adapter, what is the external diameter of the
ETX90AT?, and how much wait can the drive of the telescope handle
without problems, my camera is a Nikon n8oo8s, and may be it is heavy,
the motor of the telescope can move it without problems?
Thank you for your answer.
Mauricio Lpez

Mike here: There is no set weight limit but I can tell you from experience that an ETX-90 OTA piggybacked on an ETX-90 is too much weight. But I have piggybacked a Pentax Spotmatic as well as a PST on my ETX-90RA (which has a different drive mechanism than the ETX-90AT). As to the diameter, depending upon how you plan to make the adapter, it is more accurate to measure it yourself.

Subject: ETX images Sent: Friday, December 9, 2005 12:49:15 From: Clive Norton (norton_clive@hotmail.com) I was looking at your great site (as I am considering buying an ETX) I am not a telescopist, but do have an image analysis background. I was looking at one of your pictures of a comet, and wondered how much I could improve it with a Laplace Transform, so tried putting it through a demo version of Neat Image. http://www.neatimage.com/download.html The attachments are the results of a few seconds' work. I hope you like them... Clive

Subject:	re: Weight question
Sent:	Friday, December 9, 2005 11:59:35
From:	Ronald Sigourney (rwsig@ca.astound.net)
Does a ETX 70,80,or90mm scope/mount have the strength to handle a
webcam/camera lens piggyback., and still goto with reasonable accuracy? 
And, while I have your ear, do they support autoguiding?

Many thanks for your time.

Happy Holidays to you and your family
 Ron Sigourney

Mike here: Won't be a problem with cameras/imagers. You may or may not need to add a counterweight. See the Helpful Information: Astrophotography page for LOTS of info on astrophotography with the ETX telescopes. As to autoguiding, maybe. The Meade Autostar Suite will autoguide with the LPI and DSI.

Subject:	Meade ETX70 - Astrophotography
Sent:	Thursday, December 8, 2005 05:56:30
From:	Neill McKeown (neillmckeown@hotmail.co.uk)
I am from Ireland and am going to Turkey for the eclipse in March 06 and
I am thinking about getting an ETX70 to take with me. I read recently on
a forum about the ETX70 limitations regarding photography - see below

	"You will need a camera adaptor of the type that replaces the eyepiece
	for the eclipse. Although the ETX-70 has a rear port for direct SLR
	photography, it only works for objects up to about 40 deg from the
	horizon - otherwise the base and the camera attempt to occupy the same
	space! The Sun will be rather higher than that in Turkey."

Does the same limitation apply to the use of  the Meade LPI and/or
Toucam Pro II Webcam.
Thanks 

Neill

Mike here: Typically those are mounted in the eyepiece hole so no interference from the base.

Subject:	Digi-T System
Sent:	Monday, November 21, 2005 12:01:16
From:	Diane Rainey (diane.rainey@ncmail.net)
First just want to say I enjoy your site and the service you offer.

I have a ETX 70 and Fuji s7000 camera and a digi-t system.  Not sure how
to use it though.  I have the moon with scope in perfect view but when I
mount the camera with digi-t system I no longer can focus.  Could you
please tell me what setting I should be using on camera or what I am
doing wrong.

Thanks for any input...
Diane

Mike here: Typically when doing "afocal photography", which is what you are doing with a Digi-T, you focus the eyepiece you are using to your eye. Then you attach the camera and focus its lens to infinity. If the camera has a zoom (optical, not digital) or macro capability, you should zoom or use the macro mode to make the image fill as much of the camera's field of view as possible. You may need to adjust the eyepiece focus slightly. Note: if the camera has autofocusing, you need to disable that.

Subject:	DSI Pro Focusing
Sent:	Sunday, November 6, 2005 19:32:16
From:	Robert Zaballa (robert_zaballa@yahoo.com)
In order to focus the DSI Pro in my ETX 80, I had to use the barlow lens
so now the magnification is doubled.

I have been wanting to obtain wider fields of view. Can one use an f/3.3
focal reducer on an ETX to reduce the magnification?

Also, there is another place on the ETX that is a threaded hole. I found
that focus is possible there with the DSI Pro if the metal tube on the
front of the camera is taken off, but the camera does not thread onto
this part of the ETX because they differ in diameter. Is there an
adapter available which allows you to screw the DSI Pro onto this other
part of the ETX?

Thanks

Mike here: There are a couple of solutions to reducing the magnification: Scopetronix has a focal reducer for the ETX or you can get a wide-field adapter (see the Accessory Reviews: Showcase Products page). As to mounting the DSI on the rear port, the Shutan Visual Back should do the job and you won't have to move the tube. Again, see the Showcase Products page.

And:

Thanks for all your help. Here's a quick question. In order to get a
focused image on my ETX 80 with the DSI Pro, I have to use the built in
Barlow lens on the scope. Basically, due to the filter slider that is on
the front of the DSI Pro, the image chip is further away from the image
plane, in the case of no Barlow lens, and cannot be brought any closer
unless you could take the telescope apart, which would be dangerous.

Besides being doubly magnified, do you see any other problems with using
the Barlow lens for deep sky imaging?

I am getting this adjustable focal reducer that threads onto 1.25"
mounts; I am hoping that it, along with the ETX and DSI Pro will allow
for a focused image without need for the Barlow lens.

Thanks.

Mike here: Well, it does spread out the light reaching the imager so longer exposures will be required. Also, since it doubles the image scale, it will also double any tracking errors.

Subject:	photo
Sent:	Saturday, November 5, 2005 13:59:29
From:	HBReit@aol.com (HBReit@aol.com)
can you do digital photography and if so which cameras are available for
the meade etx90ec telescope

Mike here: Yes, you can. There are many examples on my ETX Site in the Astrophotography Galleries and on the Helpful Information: Astrophotography page. You will also find lots of info there on many digital cameras and other imagers.

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