Reading mode: Light Dark

Cemera lens Vs. Telescope...

Go to last post
N

nameIess

Leading Member
Messages
702
Reaction score
0
Location
UK
hey guys,
i'm kinda newbie so parden my silliness...

this picture was captured through a 400mm telescope



now lets forget for a little bit that the picture is of the sun, but look at how big it looks.

why cant i get that close when shooting the moon?
i have a 20D, so thats 1.6x200mmx2

yet i'm still too far from the moon.

can anyone explain?
and how can i get huge pictures of the moon or stars?

and whats the difference between attaching a telescope to a camera and getting a longer lens?

thanks :)
 
I know you said telescope but shooting directly into the sun with your digital camera can ruin its sensor.
 
dude, i said forget about the sun. i don't care about the sun i'm talking about magnification. i want to shoot the moon :\
 
400mm on a telescope means something different then 200mm on a camera lens

the 400mm stands (probably) for the diameter of the telescope, not the focal length/zooming capabilities.

Im not yet sure exactly how astrophotography works (I will find out), but I think you need to put an Eyepiece on the telescope, which also affects its depth of field.

...Im not sure if I should say more, I might be completely wrong, just look at wikipedia or other sites about astrophotography ...

--
  • 153957 Photography -
http://arne.delaat.net/
 
that pic of a 400mm telescope with a 60mm diameter and f6. something

i'm googling for more info btw. but i thought we have some expoerts here so i figured its easier to just ask :p
 
... what camera was used with the telescope, and maybe other factors more experienced people in this regard will appreciate.

Your formula 1.6x20mmx2 doesn't mean much. If the telescope pic was taken with a point and shoot then its probably much higher pixel density will get you closer, if it was taken with a film camera, then it depends on the resolution it was scanned.

But generally speaking and disregarding the sun picture, 200mm is not enough for big moon shots. Maybe you could get by with a lens like the 400/5.6 and even better if you put a TC on it. There are some experts in long focal lengths here. I have read of more than 2000mm shots and seen them (with TCs stacked) from some people. Maybe they will be of more help.
Jaimo said:
don't forget to invite alice along for the ride
Click to expand...
 
how can you take a picture of the sun with only the corona?

About your question, it seems strange to me.. the sun and the moon apparent sizes should be approx. the same, if I'm not wrong..

kind regards
perbo

--
...still finding thousands of ways NOT to take a good photo :)

http://www.perbo.it

 
perbo said:
how can you take a picture of the sun with only the corona?
Click to expand...
Specialized solar filters often have an opaque center disk to completely block the body of the sun.
 
.... all resized full frames on a 1.6 CF body, using a conventional SLR lens + TCs. On the 20D, I reckon you need 1600-1700 mm to make a full moon fill the frame, and considerably longer if the moon is half-visible or smaller.

1600 mm
http://www.pbase.com/liquidstone/image/42058598/original

2263 mm
http://www.pbase.com/liquidstone/image/54510394/original

4525 mm
http://www.pbase.com/liquidstone/image/42093141/original

Romy

--



http://www.pbase.com/liquidstone
(Over 200 species captured, and counting)
 
This was took w/ a sigma 50-500mm and a 350D. (@500mm)

You can crop this to make a "full frame" photo.



--
- - - - - - - - - - - -

If you cant DODGE it... RAM it!!!
Take pictures till it blows up!
'Nothing shoots like a CANON!'
 
A very fast crop job done in photoshop.



--
- - - - - - - - - - - -

If you cant DODGE it... RAM it!!!
Take pictures till it blows up!
'Nothing shoots like a CANON!'
 
I'm an amateur astronomer and I have built a couple of telescopes, so here's what I think...

When you say 400mm, it refers to the diameter of the mirror ( could also be a lens, but a lens that size would be really, really costly...likely in 5 figures). So the larger the diametre of the mirror, more light you gather. So you can magnify the image much more (twice more than a 200mm for the same amount of light). It's like with lens, for an analogy consider the dia of the telescope as the size of the front element of a lens. The longer your lens, the larger the front element has to be to gather "enough" light. The actual foacl lengths of these telescopes vary. Normally it is around the 1000mm-3000m at this diametre, but also remember that your eyepiece also adds some magnification.

So all in all a 400mm telescope (that's 16 inch) is a fairly big one. To give you an idea the 16" telescopes from Celestron or other good brands cost close to $15,000!
Hope that was not too jumbled up.
 
I used a $150 USD 90mm spotting scope (Celestron C90 Mak) without an eyepiece (prime focus) attached to 300D to get these moon pictures:
http://www.flickr.com/photos/lucina/tags/moon/

It acts like a 1200mm (x1.6) f/13.3 fixed aperture lens, and the moon occupies most of the frame (80-90%). I still have room for improvement with my technique.
--
-Lucina
 
lpm said:
I used a $150 USD 90mm spotting scope (Celestron C90 Mak) without
an eyepiece (prime focus) attached to 300D to get these moon
pictures:
http://www.flickr.com/photos/lucina/tags/moon/
It acts like a 1200mm (x1.6) f/13.3 fixed aperture lens, and the
moon occupies most of the frame (80-90%). I still have room for
improvement with my technique.
--
-Lucina
Click to expand...
how do you attach it ??
and focus ??
 
It could be an eclipse of the Sun.The moon covers the Sun but it leaves the surrounding.There was an 100% eclipse of the Sun this year.
 
nodoubt said:
how do you attach it ??
and focus ??
Click to expand...
To attach it, I use:

-Celestron SLR (35mm OR Digital) Camera Adapter for C90 Spotting Scope Mfr# 93635A ($27USD)
-Celestron T-Mount Adapter for Canon EOS Cameras Mfr# 93419 ($16USD)

To focus it, I use the scope's focusing knob. Going from near (20ft.) to furthest focus takes around 20 turns. It really makes you appreciate autofocus!

Here's the setup:
http://www.flickr.com/photos/lucina/149076095/
--
-Lucina
 
If you look at the home page from whence that shot of the sun came, you'll see that the author's telescopes are a Televue Pronto 70mm [diameter] f/6.9 refractor (480mm focal length), and a Meade LX-200 - 8" diameter f/10 Ritchey-Chrétien reflector with focal length of 2000mm.

With a camera attached, telescope focal length is the same as camera lens focal length. The referenced photo is probably a crop from the entire frame captured from either the 480mm or 2000mm scope.
nameIess said:
hey guys,
i'm kinda newbie so parden my silliness...

this picture was captured through a 400mm telescope



now lets forget for a little bit that the picture is of the sun,
but look at how big it looks.

why cant i get that close when shooting the moon?
i have a 20D, so thats 1.6x200mmx2

yet i'm still too far from the moon.

can anyone explain?
and how can i get huge pictures of the moon or stars?
and whats the difference between attaching a telescope to a camera
and getting a longer lens?

thanks :)
Click to expand...
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top