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Hello :)

Well managed to get a night of imaging where nothing...yes NOTHING went wrong! :eek:

Although the night was short in terms of darknes I managed to get 1.5hrs of 8min shots @ISO400 on this pair.

Although there is very little detail and heaps of noise I do plan to add more and more data on this one for a change...my mission is to get a noise free(ish) image for once! fingers crossed!

Also could really do with a focal reducer I think ;)

Please do comment on any improvments etc.

Thanks for looking,

Michael

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Isnt it great when a plan comes together? :)

Im just wondering why you stuck at ISO400 though, I thought 800 would have been more suitable. You do need more data though, just so youre not blowing the cores when you process it.

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You're on the way Michael. You do seem to have a lot of noise though. You applied darks? I'm sure you could get it quieter with an adjustment here and there but I don't know anything about DSLR imaging.

As you say, a miracle when everything works. I had an hour of IT nonesense before I got stuck in with both rigs last night. It is just the way things are...

Olly

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  • 2 weeks later...

If you are planning on sticking with this target for a while I would suggest that low iso makes v.little difference to noise at the end of the day, because of all the stacking and dark frames applied, so I'd go with 800 or even 1600.

Don't forget a few flats every time though. Acceptable dark frames can be made by recreating conditions on a similar night if you forget, but recreating the exact orientation of the camera night after night if you forget flats is another matter!

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Good Job Michael!

Things will be way easier the more obstacles you overcome, & soon you'll be enjoying the benefits of having hours of data to process!

Where does your histogram peak when using iso400 & 8min subs? Close to the middle, first 3rd & so on?

Higher iso will let you use shorter sub-exposures, easier on the guiding & less impact of satellitetrails. Iso1600 / 5min subs was the sweetspot for my f/5.3 system

Keep 'em coming!

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Thats looking really nice.

If there was really any doubt, that shows the real difference longer subs make.

Yours is better processed, but compared to my pic I posted the other day, of about the same total exposure time, theres clearly way more data in yours with 8min subs than mine with 46sec subs.

It would be good to do a direct trial and see if the ISO number does make much difference. Mine at ISO 1600 certainly looks more noisy than yours.

I cant wait to get guiding!

Ben

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Nice start Michael. As you say, a load more subs will smooth it all out. I have found the warmer weather has left me with very noisy images whatever ISO setting I use, so I am sticking with ISO800 as that seems the best with my 2min max.

Keep at it.

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Hope you don't object but I had a bash at removing that mottled background and played with the colour balance.......seems to make things stand out it bit more........ at least on my screen it does.:eek:

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Thanks for the comments folks,

I don't think I will bother with ISO400 again. I also think the 300D is quite a noisy camera at the best of times. All the more reason to save for a better one! :eek:

Thanks for the re-mix CW! The colours look alot more balanced! You have inspired me to keep playing with this one.

Thanks,

Michael

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  • 2 weeks later...

Finally got round to having another play with this, and I'm a bit happier now I have managed to subdue the background noise a bit and I think the colour balance is a tad better.

I think my problem was that I was over stretching the data. :D

Still this is no substitute for adding LOTS more data to this when I get a chance!

Any comments welcome...

Thanks,

Michael

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That last one is far batter, two points that stand out:

1. a northwesterly drift causing a slight elongation of the stars.

2. a slight sense of out of focus - probably caused by point 1.

I there's a method that others have used about using a layer copy to reduce the elongation. The result is that you end up with a naturally sharper image.

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Hi Nick,

I am glad you identified that, as I was seeing this effect when zoomed in on the stars and I was a bit worried to what it was.

I was thinking that I was asking a bit much to guide at 8mins with a REALLY rough alignment.

I was a bit worried about the watery effect on the stars also; I was thinking something more serious than focus..so I'm glad you mentioned that!

I have heard of that method being mentioned right enough, so I will look into it. I don't suppose you know if 'Astronomy Tools' plug-in for PS does the same thing with the 'Make stars smaller' macro?

Many thanks,

Michael

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