Comparison of canon 300mm F2.8L to Orion 100ED

[avandonk]

I had images from both ofthe same region so I thought I would try and compare them.

Canon 300mm F2.8L, field of view 6.86x4.58 degrees.

Orion 100ED with Astro Physics FR/FF has a focal length of 675mm and an aperture of f/6.7. Its FOV is 3.0x2.0 degrees.

300mm image 3.8MB
http://avandonkbl.bigblog.com.au/dat...0409133359.jpg

!00ED image 1.6MB
http://members.optusnet.com.au/~trlee8/100ED_7.jpg


An animated GIF of the same sky area from each 300k
http://avandonkbl.bigblog.com.au/dat...0411103821.gif



Bert

[Terry B]

Interesting. But what is the price difference?
I assume the canon lens is much more expensive.

[Peter Ward]

Which is which in the animated gif?

The bloated star image looks out of focus rather than lacking resolution.

[tornado33]

Most interesting.
Where the 300mm will shine is narrowband work with its much faster f ratio
Scott

[Bassnut (Fred)]

Thats a tease, very interesting. Fess up, which is which . 300mm F2.8?, sheesh, that sounds like a monster (and price)

[dugnsuz (Doug)]

On inspection of the high res pics, it looks like the bloated stars in the gif come from the 300mm lens. But it looks to be more of a focus issue rather than dodgy optics.

Do I win!!!???

RRP on the 300mm f2.8 is $8299!!!!!!!!!

[avandonk]

Here is an animated gif showing the same sensor area. It should be obvious which is which. What is interesting the stars are about the same size on the sensor. Which is what you would expect for two 'high' quality optics with essentially the same aperture.

The only difference is the image scale.

Animated GIF
http://members.optusnet.com.au/~fmlee/sensorarea.gif


Bert