Reprocessed Corona Australis

[avandonk]

Here is the picture, if you want details ask.
Canon 5DH, Canon 300mm F2.8L at F2.8. Hutech LPR filter, 14X360sec ISO 400, processed with ImagesPlus, RegiStar and GradientXterminator. Combined odd and even frames as median in Registar. 2x(7X360) then summed these two frames. This is then the equivalent of 7x720 sec.
2.6MB
http://members.optusnet.com.au/~avandonk1/COR_AUST.jpg

Bert

[ballaratdragons]

Geez Bert! Fantastic!!!!!!

You keep pulling them out of the hat. :thumbsup:

The High Res version is a mind blower!!!!

[iceman]

Beautiful! Sharp!

Very purpley/maroney.. that's my only unpositive comment :)

[sheeny]

There's no doubt about where the nebula is! Superb work Bert!:thumbsup:

Al.

[h0ughy]

that depends if you look at it through a empty red wine glass;) :lol:

Lovely, awesome, truly amazing:eyepop: :whistle: colour aside there is so much detail within that shot it is so hard to describe - unfathomable:thumbsup: :D

[jase]

Very nice Bert.

May I ask F/L and exp. time.

[glenc]

Bert
Vey sharp, lots of stars and the size of the nebula is amazing too.

[Garyh]

Beautiful shot Bert!!!! love that 300mm lense,
Only little niggle is the dark neb seems a bit on the red side?
Other than that, a awesome image Bert..
Cheers Gary

[tornado33]

Another fantastic image Bert.
Scott

[ving]

sweet stuff bert! :D

[Ric]

Great shot Bert, the Nebula really jumps out and grabs you.

very nice

[CometGuy]

Lovely image Bert, great detail, nice sharp stars. As others said you problably need a bit more green in the image.

Anyway, would you be able to upload a single cr2 raw file from that image to your website?

Terry

[Striker]

I missed this one...

Color looks a bit off but its a great image and sharp as.

Nice one Bert.

[avandonk]

Terry I am limited to 10MB max and a 5DH RAW file is typically 12 to 13 MB for these images. Maybe upload it to IIS?

Bert

[iceman]

Feel free to upload it to IIS (http://www.iceinspace.com.au/?iisftp), contact me for the password.

[CometGuy]

Bert,

Is that OK? Thanks Mike, thanks Bert.

Terry

[iceman]

I've given Bert the password, i'm sure he'll upload it today.

[avandonk]

Terry file uploaded here
12.7MB
http://www.iceinspace.com.au/uploads/Image_2609.CR2

Bert

[CometGuy]

Many thanks Bert got the file. I was wanting to see an unprocessed image to see just how fine the non-IS 300 2.8 lens is, no wonder they are still attracting 3-4 K Aus secondhand.

Terry

[avandonk]

Did you convert the raw to tiff or fits without any sharpening etc? By the way the 300mm F2.8 Fluorite that tornado33 has got is the earlier version of the 300mm F2.8L. The only difference is the later version has two ED elements as well as the Fluorite as ED glass was not around then. Optically the earlier lens has got slightly more off axis astigmatism wide open. It would not be as good for full frame but still nothing else would come close. The real advantage of the the earlier lens is it can easily be used with an Astro CCD as it is fully manual.

Keep an eye out for the arriflex version (very rare) as it can be easily converted to fit an EOS mount with focus at infinity. The FD mount version may be converted to fit an Astro CCD but not an EOS mount without an extra glass element to get focus at infinity which ruins the quality.

Bert

[CometGuy]

Bert,

I have seen some of the images Scott has producing with that lens and it seems to have a similiar problem with bright stars that the Sigma 300 2.8 lens has (witness his M42 image). At the same time I think the Sigma has a bit more coma on one side but at the same time has less CA. I am not sure I would gain anything apart from going to the 300 EF non-IS.

Your EF lens is a cut above, even taking into account the larger pixel size of the 5DH. The level of aberations are very well controlled for f2.8.

The latest IS version seems to be a step back (its not just Jerry Lodriguss saying this either). I would be pretty upset shelling out $6-7 K only having to use the lens at f4 for astrophotography!

For the sort of work I do (comet searching) its important to have reasonably sharp images edge to edge whilst maintaining maximum possible aperture.

Terry

[avandonk]

I always had a gut feeling that IS will only produce aberrations compared to non IS, even when turned off. Unless the 'park' position is perfectly aligned and this is highly unlikely.
You are correct the only lenses for astro that start to approach pefection at F2.8 is the Canon Super Telephoto series with NON IS. The sweet spot bang for buck is the Canon 300mm F2.8L.

I have not seen any astro images with the new Nikon F2 200mm (?) but this costs even more than a Canon.

Bert