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View Full Version here: : Wide field pics at 85mm


avandonk
20-12-2005, 07:59 AM
Decided to try the 48mm nebula filter mounted on the front of a Canon 85mm F1.8 with a reducer ring.
All pictures six exposures stacked with Registar.Each exposure 3min at ISO1600
at F2.0, in camera (20D) noise reduction on. Raw to Tiff, stacked, levels adjusted in Photoshop coverted to JPG, then filtered with Noiseware.

I am amazed to see part of Barnard's Loop.

http://users.bigpond.net.au/avandonk/Orion002_filtered.jpg

http://users.bigpond.net.au/avandonk/LMC001_filtered.jpg

http://users.bigpond.net.au/avandonk/Car001_filtered.jpg

Bert

iceman
20-12-2005, 09:02 AM
Stunning shots Bert, I love the LMC one the most.

So much red in those images! Just lovely.

h0ughy
20-12-2005, 09:49 AM
What a pleasure, simply stunning. I love the eta carina area shot the most

avandonk
20-12-2005, 09:57 AM
When I tried this with a 58mm Hutech LPR filter there was hardly any red. I think the nebula filter compensates quite well for the lack of H alpha sensitivity of the 20D.

Bert

atalas
20-12-2005, 11:31 AM
Nice shots Bert !

beren
20-12-2005, 12:22 PM
Top stuff :) where do you get those reducer rings from ?

Striker
20-12-2005, 01:28 PM
Very nice Burt...I like your ETA carina shot the best.


I also like your widfield of the Orion and Horsehead but I think the red balance is to high. the runningman should be more blue being a reflective emission nebula....but never the less I love it anyway.

Well done Bert

avandonk
20-12-2005, 01:45 PM
Most camera shops have them but 48mm almost never.
try here http://www.centre.net.au/Step_Down_Rings_0007LP.html
and http://www.centre.net.au/Step_Up_Rings_0007LN.html

Generally need two rings to get from 58mm to 48mm.

Bert

xelasnave
20-12-2005, 02:00 PM
Thats unbelievable Bert.
I could not resist seeing what was hiding in the loop. Thats a rather good Horse Head lurking in your wide field image of Orion. I cropped a section and marginally adjusted in photoshop.
Great shooting congratulations.
alex

avandonk
20-12-2005, 02:16 PM
Yes, where I am in suburban Eltham it is almost impossible to get decent seeing due to light pollution and heat pollution from neighbouring roofs except close to the zenith. But at low magnification with lenses can get by for imaging with appropriate filters.
When I get everything working well and I have got up to speed myself will try some serious imaging from a dark sky site. I am still learning.

The Canon 85mm F1.8 for its price is almost as good as an 'L'. All pics shot at F2.0 if I had closed down to F2.8 there would be no CA around the bright stars.

You are right Striker but all I wanted was to see how much red (H alpha) I could get out of F2.0, even at 85mm.

I hope the next time it is with the Hutech modded 5D and just the LPR filter as reflection blue is almost all lost in the nebula filter as it really only passes OIII and H beta.

Bert

ballaratdragons
20-12-2005, 03:52 PM
Fantastic as usual Bert!!! The new gear is really giving great results.

RAJAH235
21-12-2005, 01:16 AM
Bert, thanks for a simply lovely shot of my favourite object, Eta Carina. :thumbsup:
Others ain't too bad either....:P :D L.

TidaLpHasE
21-12-2005, 12:48 PM
:)Awsome Bert, great images.

What would you think the 50mm f/1,8 would be like for theses wide fields?

ving
21-12-2005, 12:56 PM
very nice horsehead bert :D
no m78 in that?

avandonk
21-12-2005, 03:29 PM
The 50mm F1.8 is every bit as good as the 85mm F1.8 and putting a LPR filter on the front is still OK. If you try to put an interference type filter on a smaller focal length the outer part of the image is wavelength shifted.

Bert

avandonk
21-12-2005, 03:38 PM
The nebula filter doesn't pass much reflection blue mainly O III and H beta. So the reflection blue in M78 is almost not there. If I use the LPR filter get hardly any H alpha as the 20D sensitivity is only about 30 to 40 % due to the IR filter on the sensor.The modded 5D should solve this, and with a LPR should get the reflection blue as well as the H alpha. The 85 mm lens with the 5D should then also have the same field as the 20D with a 50mm lens.

Bert

ving
21-12-2005, 03:39 PM
thats what i thought, thanks :)