Minimum exposure needed to capture horsehead Nebula

[Peco4321]

This target really excites me and I want to see what I can get with my limited set up. So I was just wondering what you think the minimum exposure time I would need and how many lights etc to end up with any kind of basic image using 150p on eq3-2, canon 1100d. I will have tracking soon. 

[PeterCPC]

The main problem will be the camera as it's not modded. I couldn't get it until I used a modded Canon. Then I got it with 300sec exposures.

Peter

[newbie alert]

First thing with deep sky objects is you need a mount that will track..otherwise your limiting your exposure to seconds rather than mins..i get better results with a iso of 800 than any higher..

[ronin]

You will need tracking first, otherwise the target moves and alignment in packages like DSS will fail.

After that comes the polar alignment, the better that is then the longer you can theoretically go for. I would go back to suggesting that you do not try for the longest you can comprehend. I think you would be better off setting an intervalometer up for a 40 second exposure, a 20 second wait and say 30 exposures with an ISO of 800. Whatever you do expect to add in aat least 50% for sensor cooling (wait time) and as 40+20 = 60 = a minute per exposure. Nice sort of round amount.

Bring the camera back and change the number of exposures to 12 or 15 - keeping the rest the same. As mentioned elsewhere put cover on camera, put it all in the fridge and just as you close the door press the go button on the intervalometer. Go make a coffee.

Then 15 minutes later you have 30 exposures and 12-15 darks. Save the images from the memory card and put them through DSS and see what comes out. Might be good, might be bad. DSS wil stack jpegs and the idea is simply to try things out and see how it goes. If all goes remarkably well and smoothly try say 40 or 60 exposures and stack those, then think about RAW files. I just suspect that leaping in trying RAW and 120 second exposures will lead to much ripping out of hair, and searching for a convenient (or inconvenient) cat to kick.

The above idea means 3 clear nights so that is 3 months just to get those.

If you get 30 exposures then the 150P and the EQ3-2 may mean the loss of a number so expect DSS to discard some, say 5 (maybe/perhaps).

 

[xtreemchaos]

ive had some fair images with a unmodded camera, I shot it widefield at iso 1600 40x45 sec exp, but mate the biggist factor is conditions, I shot it only when theres no moon with great seeing. goodluck and remember nothing is impossible.  charl.

heres my last go .

 

ps I don't let the camera cool inbetween shots, with our weather ever second counts.

 

Edited December 3, 2016 by xtreemchaos
added pic

[Peco4321]

Thanks everyone loads of great advice as ever. I don't have an intervelometer just a cable that I can lock to keep taking shots but no gaps between them. Will just see how it goes like that for now. 

[Nigel G]

I got a fair image of the HorseHead and flame nebula with 60 x 30 second exposures at ISO 1600 unmodded 1300D. 15 flat frames, 50 bias frames, no dark frames.

Also Orion and HH with 135mm lense and unmodded camera. 120x 30 seconds. All on Alt-AZ mount, no guiding.

Give it a go  

Nige.

[Knight of Clear Skies]

It's not an easy target with an unmodded camera but a member managed it the other day despite heavy light pollution. Here's my 2 minute effort on the Belt & Sword from a dark site:

This is a single 2 minute sub with a quick process, 135mm lens at f3.5, modded Canon 1100D and taken on an EQ3-2 mount. The 150P is f5, so that would roughly double the exposure time, and the unmodded camera will let through about 1/3 of the Ha signal. As a ballpark figure you might be looking at perhaps 12-15 minutes to gather a similar amount of light. The signal-to-noise ratio would likely be lower though, as each exposure introduces a certain amount of read noise. the longer you can get the less noisy the final image will be.

2 hours ago, ronin said:

After that comes the polar alignment, the better that is then the longer you can theoretically go for. I would go back to suggesting that you do not try for the longest you can comprehend. I think you would be better off setting an intervalometer up for a 40 second exposure, a 20 second wait and say 30 exposures with an ISO of 800. Whatever you do expect to add in aat least 50% for sensor cooling (wait time) and as 40+20 = 60 = a minute per exposure. Nice sort of round amount.

There is no need to wait 20 seconds between exposures to cool the camera, that just wastes valuable imaging time. When stacking in DSS I'd recommend selecting the Kappa-Sigma clip option, this does a great job of removing DSLR noise patterns when used with dithering. I rarely bother with darks myself, if the temperature profile doesn't match the lights they can introduce more noise, but I do take dark bias and flats.

Hope that's some helps and good luck, there are some brighter targets you could try first. Also, if you have a lens you can put on the camera that might be an easier place to start, polar alignment and tracking are much more forgiving at short focal lengths.

[happy-kat]

With a 85mm camera lens on a 1100d I caught it just like I knew I had it but really it was the faintest of blobs and that was 15 seconds on a manual barn door 23 images stacked. I think being realistic it could be out of reach for now but until you try you won't know.

Edited December 3, 2016 by happy-kat

[The Admiral]

Well I managed to capture it with just 64 x 15s subs using my 102 refractor and an unmodified Fuji X-T1 (though its red response seems pretty good), but it was very marginal.  You do need a motorized mount that tracks really.

https://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/?do=findComment&comment=2872568

And then I did one using 250 x 10s subs, here, which is rather better   https://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/?do=findComment&comment=2889900

This year I plan to do it justice though, and spend some time on it.

Ian

Edited December 3, 2016 by The Admiral

[Peco4321]

I had a great session last night the sky was so clear. I tried a few methods with varying results;

Camera only on tripod wide field shots of 30 sec ISO 1600. I just can't seem to get a really sharp focus. Will check tonight and process to see what's there. 

Prime focus 8 sec ISO 6400 twisting the slo mo controls, very crude I know, but I am sure there is some faint red nebulosity there. Again I will check later. 

[Peco4321]

Done a bit of processing now, stacked just 4 images of 10 secs, 4 darks and 10 bias, with the crude twisting I have got a reasonable image and I am very pleased.  Not Horshead but I think its the Flame Nebula, please put me right, or wrong, not bothered, just would like to know, thanks.

 

Bit more processing. 

Edited December 5, 2016 by Peco4321

[happy-kat]

Yep a bit more of a fiddle in levels moving the mid point slightly and it's there quite clearly.

Very steady mount control I would imagine to manage that. Excellent.

[Davey-T]

Yes, that's the Flame, HH is down to the right a bit.

Dave

[laser_jock99]

I had a look through my old images to see what sort of exposures I had used to capture the Horsehead. You basically don't need that long an exposure to see it.

 

Using a 12" F4 Newtonian scope and unmodded DSLR @ ISO3200 I got this in 300 seconds

 

Using a smaller 6" but optically faster F2.8 Newtonian scope and modded DSLR, i captured the area in 142 seconds.

[Peco4321]

Thanks laser_jock99.  They're great images of a wonderful target. Can't wait to get the motors fitted to my mount after xmas for longer exposures on this. 

[Peco4321]

Got my motors fitted now and had a brief go the other night and this is a 30 or 45 sec single exposure ISO 400. Next time I'm going to have a go at getting more and do some stacking. Apologies for the circle, I have this facebook thing going with all my friends were I dedicate a picture of something in the universe that reminds me of them, this is for my niece who is on an Equine course at university, so I needed to show where the HH is. 

Other objects I have dedicated so far for friends:

Kanes crater on the moon for a colleague called Kane

Carolines cluster near Caseopiea for a friend called Caroline!

The running man Nebula for a friend into cross country fell running 

The fishes Mouth of Orion Nebula for 2 friends into fishing 

The Alpine region of the moon for my brother who runs his own ski holiday business 

The Ring Nebula for a friend who forgot the wedding rings at his own wedding  

Capella for family who live near Rotterdam in a place called Capella a/d Ijssel  

I find this facebook thing of mine a good way of getting some info out to people who otherwise would never know what's up there.  Maybe it's a bit self indulgent of me, but friends seem to like it ?  

 

[SkyGuy69]

You do not need a modded camera to shoot the Horse Head or any nebula. If you have a Canon DSLR camera the only real issues are related to noise or light pollution itself. All you need to do is buy a UHC EOS Clip Filter that snaps inside the camera over the glass or mirror.

 

Here are two links to where you can buy them from:

 

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p6652_Astronomik-UHC-Clip-Filter-for-Canon-EOS-cameras-with-APS-C-sensor.html

 

https://optcorp.com/products/astronomik-eos-clip-uhc

 

 

 

[Demonperformer]

There was a thread on here a few years back of someone who had captured HH with just 2 second exposures, but IIRC he took many hundreds of them. But this is probably not the easiest way to do it! 

[Gerry Casa Christiana]

On 01/01/2017 at 17:25, Peco4321 said:

Got my motors fitted now and had a brief go the other night and this is a 30 or 45 sec single exposure ISO 400. Next time I'm going to have a go at getting more and do some stacking. Apologies for the circle, I have this facebook thing going with all my friends were I dedicate a picture of something in the universe that reminds me of them, this is for my niece who is on an Equine course at university, so I needed to show where the HH is. 

Other objects I have dedicated so far for friends:

Kanes crater on the moon for a colleague called Kane

Carolines cluster near Caseopiea for a friend called Caroline!

The running man Nebula for a friend into cross country fell running 

The fishes Mouth of Orion Nebula for 2 friends into fishing 

The Alpine region of the moon for my brother who runs his own ski holiday business 

The Ring Nebula for a friend who forgot the wedding rings at his own wedding  

Capella for family who live near Rotterdam in a place called Capella a/d Ijssel  

I find this facebook thing of mine a good way of getting some info out to people who otherwise would never know what's up there.  Maybe it's a bit self indulgent of me, but friends seem to like it ?  

 

As your doing shorter exposures. I would bump up the ISO to at least 1600 you could even try 3200 a lot of my pictures in the beginning on a non modified camera were like that. Yes you get more noise but with processing you can sort it out. 

[Gerry Casa Christiana]

http://www.sensorgen.info/CanonEOS-1100D.html

in fact if you look at the read noise for your camera you can get away with bumping up the ISO. Try it you will be suprised by the results. Yes I know about losing dynamic range but in the beginning I got pictures like this with no guiding and no modification. 

[Stub Mandrel]

2 minute unguided subs on a 130P-DS

 

[Peco4321]

I've improved a bit on this target. As you can see, light pollution is the problem. 

[Stub Mandrel]

49 minutes ago, Peco4321 said:

I've improved a bit on this target. As you can see, light pollution is the problem. 

I'd say that was vignetting. Are you using flats? Very careful use of gradient exterminator should help you get an even better result from that data.

[adder001]

I would love to get the horsehead even close to that. My biggest problem is to my south are 3 football pitches with lights as well as usual LP. I have been trying to get this target from my back garden since last year, but nothing as good as that. This is my latest attempt and thats with a star adventurer with 200mm lens, 30 second subs x 60. I definitely need to goto a dark site but I cant find anywhere suitable or anywhere that I would be happy/safe with my astro gear out.