M33 - 290 minutes of DSLR Data with 130P-DS

[Stub Mandrel]

I need some framing practice, as when I try to add up pictures from several nights, the useful area gets smaller and smaller. An example is this picture of M33, but as the impact on noise and detail of using nearly five hours of data is so huge and the actual long thin image framing looks so nice, despite losing a bit of the galaxy, I am happy to go with this.

The icing on the cake was getting about two hours last night which, although the moon was up and the background was a bit noisy, benefited from the streetlights being off. When added to the earlier data, the noise magically dropped away to a much finer scale, that said there is still a noisy background and I'm sure this would benefit from more subs on darker nights.

[StargeezerTim]

Nice one Neil... I've had difficulty getting a decent image of this one in the past... must try again! You are getting a lot of noise... perhaps you could try stretching a little less. What iso did you use? Some thing I tried a few days ago was too firstly reduce the output levels in PS on the autosave file before doing any more processing. I moved the slider from the right and reduced it from 256 points to about 130. I then processed as normal and it ended with less noise. Don't ask me why it worked! 

 

[Pompey Monkey]

Neil, assuming that you have dual-axis drives on your EQ3-2, you could try using plate-solving to get bang on target over multiple sessions.

It requires a bit of a learning curve, but a relatively small one in AP terms.

I heartily recommend Astrophotography Tool (APT) combined with All Sky Plate Solver (ASPS), both of which are free, although you can later purchase more functionality in APT for the price of a pub-lunch

The first time you see it working, you'll think it's witchcraft!

[John78]

As commented - plate solving is your friend, AstroToritilla or the APT inbuilt tools.  I have basically the same kit as you except I've got a guided EQ5 and non-astromoded camera - ashamedly I haven't got anything as half as good as this yet.

 

How long were your subs?

[Stub Mandrel]

I've had a go at a bit of noise bashing - less stretched but blended in some of the contrast enhanced core of the galaxy.

The first session was IS01600, but the later ones and most of the data are ISO800, which is supposed to be much less noisy.

No plate solving yet - I am trying to avoid having a PC as part of the setup. That may change if I go to autoguiding.

I also need to try Backyard EOS.

 

[Kropster]

I also have the 130P-DS and EQ3/2 setup.

This is very encouraging!

Looks like you were guiding. Is that right?

[Stub Mandrel]

16 minutes ago, Kropster said:

I also have the 130P-DS and EQ3/2 setup.

This is very encouraging!

Looks like you were guiding. Is that right?

No, I just kept the subs to a minute, but I suspect I could get away with two minute exposures.

The EQ3/2 is a badly misrepresented mount. Put it on a solid tripod and it is better than people think.

[StargeezerTim]

The second process is much nicer! Brilliant to get such a result with 60 sec subs. Did you use a LP filter or anything?

[Stub Mandrel]

Yes, just an inexpensive LP filter.

[Tommohawk]

Hi Neil

Thats a great image for such short exposures and the framing is attractive as you say. Interested in your views on the EQ3. I've been considering getting one as a travel mount - was that image with the 130PDS? Have you used it with the 150?

[Tommohawk]

Doh! Should have read the title! 130PDS it is then!

Still curious to know if youve put the 150 on the EQ3 though?

[Stub Mandrel]

I started using the 150PL on the EQ3 for a year. This is the sort of thing I got using it:

 

 

Should add that I use an EQ5 tripod with both scopes and the EQ34 mount

[Xplode]

You seem to got your mount, scope and editiing handled very nicely, but you struggle with noise.

Are you capturing with RAW and using calibration frames?

 

Which camera are you using?

[Stub Mandrel]

14 hours ago, Xplode said:

You seem to got your mount, scope and editing handled very nicely, but you struggle with noise.

Are you capturing with RAW and using calibration frames?

 

Which camera are you using?

A 450D. I am in a fairly light-polluted location.

I will try the Olly P. no-darks approach and see what happens.

[Tommohawk]

Not sure if you process the stars and the DSO separately? 

So the data is stretched for the DSO, and less or not at all for the stars. Similarly you can apply noise reduction to the background only if you wish. Looking at the 2 images you sent form the 150 it looks like you may do this already?

 

[Stub Mandrel]

The second one has a second LUM layer sharpened in Astra but masked to only be the DSO at about 50% opacity. I may have over cooked it.

[Tommohawk]

3 minutes ago, Stub Mandrel said:

The second one has a second LUM layer sharpened in Astra but masked to only be the DSO at about 50% opacity. I may have over cooked it.

Maybe overcooked a bit - but if you're unguided with shortish subs you'll be stretching a lot. Sounds like you're on the case with processing, just that if you're unguided you dont have long subs. 

[Stub Mandrel]

7 hours ago, Tommohawk said:

Maybe overcooked a bit - but if you're unguided with shortish subs you'll be stretching a lot. Sounds like you're on the case with processing, just that if you're unguided you dont have long subs. 

If these street lights are out permanently I can experiment with longer subs :-)

[Stub Mandrel]

Here's a comparison, a gentler reprocessing of the original data, then a reprocessing using no darks at all, both done with the aim of minimising noise rather than getting detail. I haven't compared them side by side yet so this will be interesting for me!

This one is less dramatic, but the blue halo appeared magically when I combined LUM and RGB:

This this the one with no darks, I've been much gentler on the colour too:

 

[Tommohawk]

Maybe something between the two? Taken the liberty of having a fiddle myself, but not sure if you'll approve! So much of this is personal preference.

I reduced the noise a bit but less so on the DSO itself; probably would work better on original tiff:

 

[Stub Mandrel]

Feel free to fiddle!

It's a great way for me to learn.

[Kropster]

I am surprised at the good results without Darks.

I always imagined they were essential.

Is that just propaganda?

[Stub Mandrel]

1 hour ago, Kropster said:

I am surprised at the good results without Darks.

I always imagined they were essential.

Is that just propaganda?

Olly says it is, for DSLRs with plenty of subs anyway.

 

[Kropster]

15 minutes ago, Stub Mandrel said:

Olly says it is, for DSLRs with plenty of subs anyway.

 

Good to know. One thing less to worry about.

[DanWebster]

I couldn't see what it is you're using to process your images, but I did a fairly aggressive noise reduction in paint.net, which has cleaned it up quite nicely I think.