M101

[kirkster501]

The more lum you gather (up to a limit) the better the image will be.  It is incontovertible.  However, dimishing returns kicks in after about 30 subs.

Luminance is king.  If you have to cut back on imaging time on a project for whatever reason, luminance is NOT the channel to cut back on.

[bluedandelion]

Rodd, you are correct. The data quality does matter but, as you say, your sampling looks fine. The reason I rescale the drizzled image is that I usually don't have enough frames to keep the upscaled version and noise is then an issue. If I rescale to the original resolution, I get a nicely integrated version. Also, the thing about the LRGB work flow is that you can bin the color 2x2 and upscale. This saves a lot of time on collecting RGB which you can then devote to getting more lum.

Ajay

[Barry-Wilson]

On 17/02/2018 at 21:47, Rodd said:

But regardless, I think the regular integration is better, at least with the "limited" data.  here's the non drizzled version. 

This is the version for me Rodd - a balance between all of the elements within the composition.  Well done!

[Rodd]

1 minute ago, Barry-Wilson said:

This is the version for me Rodd - a balance between all of the elements within the composition.  Well done!

Thanks Barry--I collected 32 10 min lum subs and am currently trying to compose a proper LRGB.  The jury is still out!

Rodd

[Rodd]

3 hours ago, kirkster501 said:

The more lum you gather (up to a limit) the better the image will be.  It is incontovertible.  However, dimishing returns kicks in after about 30 subs.

Luminance is king.  If you have to cut back on imaging time on a project for whatever reason, luminance is NOT the channel to cut back on.

I got 32 10 min from last night.  We'll see.  So far I am more frustrated than satisfied.

Rodd

[kirkster501]

3 minutes ago, Rodd said:

I got 32 10 min from last night.  We'll see.  So far I am more frustrated than satisfied.

Rodd

That’s why you need to persevere with it.....  Myself included......

[Rodd]

 

Well--here's what I got so far.  It is actually a blend of the new LRGB and the previous...a bit sharper, but it needs to be tightened up in many respects.  Sometimes I feel like I am trying to tie my shoes with mittens on. I do think its an improvement.  then again in the morning I may wonder what I was thinking. I know the background is to dark--but there is allot of noise in the image.  It was hazy.  

 

 

 

[Rodd]

Here's a bit less bright--toned it down a bit--seemed to be glaring at me.

 

[Rodd]

A second attempt.  Not sure which I like better...

 

[bluedandelion]

The second one has better color which draws your eye to more detail. Like it!

Ajay

[Rodd]

15 minutes ago, bluedandelion said:

The second one has better color which draws your eye to more detail. Like it!

Ajay

thanks Ajay

Rodd

[Rodd]

Here's the final image--Note the Ha regions that are visible though no Ha was captured.  Its nice to get lucky once in a while!

 

Or this one toned down just a bit

[AKB]

5 hours ago, Rodd said:

Note the Ha regions that are visible though no Ha was captured.

Yes, looks like that to me too.  Really nice, and no expensive filter or long exposures!

[Rodd]

3 hours ago, AKB said:

Yes, looks like that to me too.  Really nice, and no expensive filter or long exposures!

Thanks AKB.

Rodd

[iapa]

20 hours ago, kirkster501 said:

The more lum you gather (up to a limit) the better the image will be.  It is incontovertible.  However, dimishing returns kicks in after about 30 subs.

Luminance is king.  If you have to cut back on imaging time on a project for whatever reason, luminance is NOT the channel to cut back on.

Does exposure duration not also have impact?

I'd expect that 30 x 90s subs would be better than 30 x 60s?

In which case, would you not then want 45 x 60s?

But, diminishing returns from 30 subs upwards would render the last 15 point less?

Still trying to get my head around that one

 

 

[Rodd]

4 minutes ago, iapa said:

Does exposure duration not also have impact?

I'd expect that 30 x 90s subs would be better than 30 x 60s?

In which case, would you not then want 45 x 60s?

But, diminishing returns from 30 subs upwards would render the last 15 point less?

Still trying to get my head around that one

 

 

Longer is always better--providing your skies can handle the exposure time, which for lum can be an issue (it is for me).  But the real question is what is better 18 10 min subs or 36 5 min subs.  Total exposure is the same, but for a lum, you can go deeper with longer exposures--but then you might need 2 (or 3) nights.  Ideally, you want to expose for the max time your skies allow, form as many subs as you can get up to the diminishing returns point.  For some of the very efficient sensors with low noise (ASI 1600 et al) hundreds of 20 sec exposures can accomplish allot--even in Ha.  I don't think data (good data) is ever pointless.  It will do SOME good.  It might not be as important as data in a smaller data set, but it still is nice to have allot of data to choose from and include.  You have to collect allot of data before it is completely irrelevant.

Rodd

 

[Rodd]

To be thorough I am posting one last image--I reduced a bit following the less is more approach--the outer reaches of the galaxy should not be a bright as the center.  I think this more realistic.  If I want a better background I will have to collect more lum during a better evening (darker and less haze/high cloud).

[Rodd]

 

Sorry folks....one more image.  This is what happens when you throw spaghetti (not the word I wanted) against the wall to see what sticks.  I am going for realism and the above is just too bright.  How about this