Omega Cent.and A in one field with EasyHDR

[avandonk]

The colour balance is not quite right but all the detail in both objects are there without blowing out any bright areas. If you look carefully there are quite a few dim galaxies peppered in the background.
I still have a lot of learning to do with this method as it produces as many problems as it solves. It is an unwritten law of the Universe that you don't get anything for nothing.

Thought it was worth this large image 2.7MB
http://members.optusnet.com.au/~cheekyfish/OC&CA_HDR.jpg

Details
Canon 5DH, Canon 300mm F2.8L at f/2.8, 20x1 min, 8x4 min, 4x16 min, at an ISO of 500, ambient temperature 8 deg C at start 6 deg C at finish. Fridge temperature -11 deg C. No sign of condensation yet.
Used Images Plus and RegiStar to produce three stacked images at each exposure level and used EasyHDR to produce an LDR TIFF.

Bert

[h0ughy]

Fantastic, WOW factor in that shot. not sure but is there a comet in that shot too? i am checking now?

[duncan]

Nice shot and quite a few faint fuzzies in there too.:thumbsup:

[Astroman]

where you looking Houghy, if you are reffering to the one above 5128 and a bit to the right with a funny looking tail on it thaen its actually NGC 5090 and ngc 5091

[Ingo]

Beautiful, but putting it in photoshop and doing auto levels, contrast, and color can most of the time help.

[JohnH]

Bert,

These images are really interesting, great results, you have inspired me to give it a go.

Just one minor point, there is quite a lot of coma with the lens wide open - I imagine there would be much better performance with it closed down one stop...assuming your tracking is up to it, perhaps you could go up to iso800 to compensate without too much noise (I am gusssing the dynamic range loss would not be an issue with this technique), it is all a compromise I suppose...

[Dr Nick]

fantastic image! ;)

[Ric]

A great image Bert, everything is so sharp and clear.

A top effort

[Satchmo]

Not in this case. Omega Centauri looks far more `burnt out ' in your version. ;)

[acropolite]

Beautifully captured Bert. :thumbsup:

[avandonk]

It is slight astigmatism johnH. I defy you to find a better widefield. When you understand what aberrations are I will help you until then please at least know what you are talking about.
As for tracking you have to be joking!

Bert

[rat156]

That's a bit harsh.

OK, better widefield lens, Nikon (Nikkor) 28mm f1.4. Has to be the best widefield lens made. If you can affor the $3k US for it!

Cheers
Stuart

[Ingo]

I don't think so, I just think it's because of the low quality this forum allows to upload it in.

[RB]

That's a lovely capture Bert, Omega Cent's core is well resolved, there's great detail captured in Cent A and noise levels very well controlled using the cooled 5D at ISO 500.

That lens performs beautifully even wide open and tracking is spot on.
HDR is a very exciting area of photography to explore and offers a lot of potential.

As a side note I've included the MTF charts for both the lenses mentioned here for comparison, even though they are very different F.L which affects their characteristics.
The first is the Nikon (Nikkor) 28mm f1.4 and the second is the Canon 300mm f2.8.

Also I don't think the file limit is the issue here Ingo, there's much more to colour correction than just using auto levels, contrast, and color in PS.

:)

[2020BC]

A very interesting and useful widefield. Puts stuff into context for us. I like it. :thumbsup: One day I'd like to try this and I hope it comes out this good.

Bert, you've been doing some great stuff with that cooled DSLR. Can you get by without using dark frames at -11 C, or is there still a bit of noise around at that temperature? :confuse3: Also, do you have a pic of that fridge setup?

[JohnH]

No need to be rude mate.

I observed trumpet shaped stars in the full frame, the effect lessens as you aproach the centre of the image but does not disappear completely, so yes I agree there is astigmatism present and lateral chromatic aberration and, for that matter, even a diffraction effect can be seen, which is curious since the aperture diaphragm was not stopped down.

I am very well aware of the quality (and cost) of the Canon L series lenses thank you, I dream one day I might own one or two ...but even they can benefit from being stopped down no? I did say this was a minor quibble - sheesh...but there IS coma present as far as I can tell, perhaps it in not the major abberation in this image but the trumpet effect is worse the further off axis you go, as I understand it astigmatism would not account for that on its own...

[Ingo]

Nikons super telephoto's are used in space by NASA with Kodak-Nikon hybrid bodies.

Canon is not on their photography equipment list at all for anything.

That should tell you something about Nikon's lenses.

[avandonk]

Yes it does. NASA is on a budget!

Next trip it is P&S cameras only.

They also left a Hasselblad on the Moon. Seems a long way to dump junk.

I do not want to get into any sort of slanging match.

Put up some pictures of equal quality taken with any lens of your choice. I don't really care what sort of aberration it is as long as it is almost imperceptible!

To get really serious and all jokes aside I am only here to share my long journey in astrophotography with others.

Quibbling over trivialities is a waste of time.

I personally don't give a damn what other people think or hold dear.

JUST SHOW ME YOUR IMAGE!

Jase has just put up the best image I have seen of M8 and M20. Shame it was not at a higher resolution so we could really see what was there! Maybe his FSQ.. something or other has ADHD!

Bert

[Octane]

Bert,

Do you mean to say that you're not here for (constructive) criticism of any kind, whatsoever?

No honest or helpful advice which may be written to perhaps try and assist (note: not detract) in your quest and journey? So long as its praise and ego-stroking; as long as you think your images are the greatest ever taken of whatever object posted, that's all that matters?

Being and having critical imagers (and I've noticed that even the more novice imagers, myself included) on this forum, can't help it if the first thing we do is view the image at its full size and look at the corners before we look at the focal point. It just goes with the territory. It isn't meant to detract or take away from the effort put into your work.

Regards,
Humayun

[avandonk]

It is very simple Humayan I don't like half baked assertions and or glib statements. It tends to make me over react. I am sorry if I have offended any one.
You are one of the few that puts up images at high resolution. They are all very good.
Rational critique is always welcome. I know for a fact that to get pin point stars on a full frame sensor is difficult. I have modified all my optics to address this problem apart from the Canon 300mm F2.8L. If I want pinpoint stars with no nebulosity I will get myself an f/20 optic. It is about balance and compromises.

I am not defending my position just asking for any one who makes a comment to at least know what they are talking about. It is just as valid for me to doubt their opinion.
When I say I don't care, it is only the ignorant glib and facile statements I am refering to.

In this case the 'aberrations' and who cares what the label is in this image are only visible when the image is viewed with a lateral dimension of over a meter! That is a magnification factor of about thirty!

It would be a sad day if we all agreed all the time.

Bert

[JohnH]

Hmm, I guess that is aimed at me then, half baked, ignorant glib and facile...nice Bert, thanks!

While you are at the keyboard mate I STILL do not have a clue at to why you shot this wide open as opposed to down one stop...given the difficulty in getting such a wide shot in the first place and given you say tracking is not an issue etc....good as it was would this shot not have been even better taken at f4?

[avandonk]

No JohnH it is not aimed at any one. I am trying to get the faint nebulosity of Centauras A. Losing half my speed for nebulosity is not even a consideration to get tight stars that any lesser aperture can give me. I suppose I could collect star data and do some photoshop magic.

Sorry but this is the end of the matter as far as I am concerned.

Bert

[rat156]

Hi Bert,



So then you go on to make some...



No kidding.



Now I see what you were on about, you wanted to get the nebulosity, in which case f ratio is the governing factor, the minor flaws in the image from optics were secondary.



Agreed, no I meant disagree, I'll come in again...

Cheers
Stuart

[circumpolar]

Thats a great shot. I'm going to see how many fuzzies I can find and compare in Uranometria.

[jjjnettie]

I like it. Lots.
It sets a standard to aim for.

[skeltz]

OH bert did you ever get your twin stereo hubble???
my name is earl!![ thats karma mate}:poke: :einstein:

[skeltz]

looks to me like your focus is not spot on to start with i am no expert or maybe it is your lense?maybe you need that twin hubble you were talking about???

[avandonk]

Sad Sad Sad

Bert