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2020BC
26-05-2007, 04:31 PM
Subject: The Coal Sack near the Southern Cross
Lens: 50 mm Canon EF-II f1.8 @ f5 (No filters)
Exposure: ISO1600 Noise reduc off (4x2Mins) + (8x1Mins) [16 mins total] 10 darks
Camera: Canon 350D unmod
Mount: LXD-75 unguided
Process: Photoshop
Date: 20May07 p.m.

Click here to view (http://www.zodiaclight.com/images/CoalSackLens50mmf1.8Atf5nofilter16M insMerged1600ISOUnguided20May07Web1 280Poster.jpg) (Size 1.1 MBytes)

[1ponders]
26-05-2007, 05:37 PM
Nice shot Bill.:thumbsup:

glasseyes
26-05-2007, 05:56 PM
What a great image Bill, that little Canon 50mm f/1.8 is a winner !
What produced the diffraction spike around (what I think is) Acrux?

2020BC
26-05-2007, 06:30 PM
:D

Thanks, guys. The diffraction spikes occur via the edges of the blades in the lens' iris. In a way similar to what happens with a telescope's spider the spikes will manifest mostly for the brighter stars.

For someone on a budget (like me) the Canon EF 50mm f1.8 II lens is a "must have" at $139.00. I can't recommend it enough in terms of "value for money".

Experimenting wide open at f1.8 it is very fast and is still pretty sharp in the centre (at f1.8 it has plenty of 'coma' surrounding the centre), but when stopped down a little bit (say to f2.8) it really gets a lot sharper. At f2.8 it is much, much better than the f4 kit lenses that come standard with a new 350/400D. Stopped down to f5 you can see how sharp it is. A very versatile lens - for $139...

Ric
27-05-2007, 11:09 AM
A wonderful image Bill.

Cheers

tornado33
27-05-2007, 10:54 PM
Yes great image there. I have that same lens, it is excellent value for money, and stopped down to F5 like this performs excellent.
Scott

Dr Nick
01-06-2007, 05:10 PM
Well done! ;)