Hubble deep field

[SteveBz]

Hi People,

Has anyone tried to image the Hubble Deep Field in UMa with amateur equipment? It's 2.5' and that's planetary size, so with a Barlow, a bit of drizzle,  a DSLR and some patience it should be possible to get something.

I'd like to see if anyone has tried.

Regards

Steve.

[carastro]

I know some-one who tried (not on this forum), and I think Pete Lawrence did a challenge on this a couple of years ago, not sure if they are posted up anywhere.

Is Pete a member on this site?  If so maybe he will reply. 

Carole 

 

[Ouroboros]

HYep. I amongst several others on her have tried it.  Here is my effort, but others did far better as you'll see if you search the thread. It was obtained on 19 April 2015. 14x150s + 10x300s canon 450D attached to SW 200p Newtonian, no Barlow. There's more than one Hubble Deep Field isn't there. This was the one near Ursa Major as I recall.  Good luck! 

PS I forgot to add. The grey square is my effort next to Hubble's for comparison. And the lines and little rectangle show the expanded area of the frame it came from. 

 

[Macavity]

I think there *were* posts here... Pete... The BBC... Something
motivated me to try anyway! And I was pleasantly surprised. 

Just as random encouragement (There are far better images):



For what it's worth, I was using an 8" f/4 Newt with a Watec integrating
video camera. Reaching approx Magnitude +19 with a 40 min exposure?
The difficulty is that it is (obviously) in a region of few stars... But even 
with my "dodgy" HEQ5 and Stellarium Maps, I was able to "Star Hop".

[SteveBz]

Good efforts guys. What sort of skies did you have?  Did you use light pollution filters? If so what sort?

If we ever have clear skies again, would be quite fun to try.

[Rodd]

I think you'd need a dark sky and a lot of  LONG exposures with a very long focal length to really be able to do it.  Probably just Lum--Talk about a challenge!

Rodd

[Macavity]

I think one can take encouragement from the following
(albeit miniscule version) graph. Basically it says that if
you have SOME sort of dark sky you might reach limits
of magnitude you may not have dared to envisage...

[Ouroboros]

The Sky at Night website still has the page describing the Hubble deep field challenge with star charts to show where the region is. Link here to Hubble Deep Field  challenge. 

[Freddie]

It's here. As you can see, various scopes and cams used, including mine, so should give you some ideas.

 

[SteveBz]

1 hour ago, Macavity said:

I think one can take encouragement from the following
(albeit miniscule version) graph. Basically it says that if
you have SOME sort of dark sky you might reach limits
of magnitude you may not have dared to envisage...

Hmm. I don't know how to measure sky brightness.

My attempts last year with a D5000 Nikon and an 8in Newtonian were getting 14th magnitude stars quite nicely.  The HDF has objects from 18-22 and greater.

Now I've upgraded to guiding and a 2in light pollution filter they should do better, but I haven't been out yet this season.

[Macavity]

2 hours ago, SteveBz said:

Hmm. I don't know how to measure sky brightness.

If you have Mag +5 skies the sky background is +19.5 etc. 
And there is always the commercial "Sky Quality Meter"...

I can estimate the visual limit of my skies. I am less sure of
this bit: But (background) "sky brightness" is *random*, so 
so stacking might be able to boost the signal above this?  

[Ouroboros]

7 hours ago, SteveBz said:

Good efforts guys. What sort of skies did you have?  Did you use light pollution filters? If so what sort?

If we ever have clear skies again, would be quite fun to try.

The sky brightness was 21.6 mag/arc-second according to my sky quality meter. I have quite dark skies in Cornwall, at least at the zenith and towards the north, which the target was of course. 

I forgot to mention I used an ISO of 1600, whereas normally I'd be down at 400, but I was just going for maximum signal and not caring too much about image quality. 

I think it's fun to have a go at this sort of thing regardless of the skies you have. 

[Rodd]

The visual limits are very much different than the imaging limits.  In a 20 min or 20 min exposure, a 4" scope can pull in stars way, way to dim to be seen visually with the same scope--even in a dark sky site. 

Rodd

[SteveBz]

8 hours ago, Rodd said:

The visual limits are very much different than the imaging limits.  In a 20 min or 20 min exposure, a 4" scope can pull in stars way, way to dim to be seen visually with the same scope--even in a dark sky site. 

Rodd

Hi Rodd, the problems I have are light pollution. I live near Gatwick airport. I took a 30 sec photo of m57 last night with a Skywatcher Light filter and it was ok, but still the sky was not black. I'm thinking of upgrading my light filter but obviously narrow band filtering would not work for deep field stuff because the large red shift would move the h-alpha line, plus most of those galaxies are old, red stars rather than the white stars we have here in the Milky Way.

When the nights get longer I will have a go.

[Rodd]

44 minutes ago, SteveBz said:

Hi Rodd, the problems I have are light pollution. I live near Gatwick airport. I took a 30 sec photo of m57 last night with a Skywatcher Light filter and it was ok, but still the sky was not black. I'm thinking of upgrading my light filter but obviously narrow band filtering would not work for deep field stuff because the large red shift would move the h-alpha line, plus most of those galaxies are old, red stars rather than the white stars we have here in the Milky Way.

When the nights get longer I will have a go.

A serious challenge for sure.  LP makes everything harder--and that is when the target signal is stronger than the LP.  In this case, the targets are probably well below the LP limit.  I guess dark sky sites are coveted for a reason!

Rodd