TELESCOPE W/ T MOUNT ASTROPHOTOGRAPY question???

patrick in memphis

Senior Member
hello. i received a new toy for Christmas in the form of a telescope for my photography"hobby" lol. i got the tele generally set up and took some shots of the moon however i cant get the moon all in one shot.is there a way to zoom out since i am only using the t mount.also what is the best shooting mode m/a/s/p in manual mode i cant pick aperture since no lens but i compensate with shutter speed for brightness. also any other tips would be appreciated since the whole telescope concept is new to me.
 

Marcel

Happily retired
Staff member
Super Mod
I don't think you can zoom out from a fixed focal lenght lens (telescope). For exposure, since the telescope does not have aperture blades, you'll probably have to use manual mode (m) and with trial and error find the right shutter time and iso value to give you the exposure you want for your picture.

Enjoy!
 

Pierro

Senior Member
More info required - are you using prime focus astro pohotography, or are you using eyepieces ?

If prime, ( no glass, eg lens or eyepiece, between camera ) then you cannot zoom. Scopes dont zoom, unless you use eyepieces, and even then you would need a zoom eyepiece.

You must have a fairly big astro lens to be filling the viewfinder so much you need to rack out. My previous 600mm scopes would easily see the whole moon and then some.

What exactly are you using Patrick ?

By the way, assuming its a refractor, you can stop down but its far from technical and very easy to do
 

patrick in memphis

Senior Member
CELESTRON 114AZ REFLECTOR TELESCOPE W/TMOUNT its about a 4 ft long barrel roughly 5 in diameter i did not use eyepieces just tmount to barlow to tele supposedly capable of 675x im sure thats with the eyepiecs installed
 
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Pierro

Senior Member
Ah, if its the Celestron in your siggy, then obviously its not a refractor, but a mirror scope.

Now then, it appears to be a 900mm scope, but that on its own would not make the moon fill the VF ( i think ) It appears that the Celestron comes with eyepieces and 3x barlow. With any of those eyepieces attached, it will increase the 900mm reach a helluva lot. With the Barlow, it will triple them, because its the scope equivalent of a Teleconverter.

Try the largest eyepiece, the 25mm as its the lowest power ( all the EP's that come in the kit are fixed, so you still wont be able to zoom out ) and do not use the Barlow and see what happens
 

Pierro

Senior Member
The bigger the eyepiece mm, the smaller the magnification. The 7.5mm will have huge magnification...but they still dont zoom. None of you eyepieces zoom in or out. They are fixed lengths. The barlow will just triple the magnification of any eyepiece you mount

Can you mount the camera with T Mount directly to the scope ? In other words, no EP's no Barlow .

I only have experience of using Refractors for prime focus photography

If you want to use the EP's, you will need to attach a lens to your camera and a way of connecting the filter thread of the lens to the thread of the eyepiece, using an adapter ... assuming the EP has a thread. If not, adapters are available. But this is not the best way for connecting camera to scope
 
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Pierro

Senior Member
You certainly can Patrick. The Barlow is just a Teleconverter to increase the magnification of any eyepiece you mount. Its a 3x Barlow so it will increase the mag by 3 times. No wonder you cant see all of the moon
 

SteveH

Senior Member
Hi All,
I used to have a Celestron scope a few years back, and I always found it diffcult to capture the moon using a astro-webcam. The reason being, that the webcam actually had a 12mm magnification factor.
After a little research, I found I found that not only can you get extenders (Barlow lenses) but also focal reducers - These are similar to the Barlow you have, but will reduce the focal length of the scope and eye pieces (Or in this case, your camera). Have a look at buying one of these as I believe it is the only way to get the whole of the moon with your current scope.
 
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