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The Dumbell Nebula


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3hrs of data on the Dumbell Nebula M27 no flats (still giving me grief ) came out better without so i need to bin that EL panel more grief than its worth ,anyway im happy with this enough data to make

That's really nice David, great contrast and colors.   Whats the problem with the EL panel, it's all I've ever used for flats.

That is stunning David. Love the colours. 👍

silentrunning

That's really nice David, great contrast and colors.

 

Whats the problem with the EL panel, it's all I've ever used for flats.

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Bottletopburly
53 minutes ago, silentrunning said:

Whats the problem with the EL panel,

i was having problems with lines which i do seem to have eradicated i put a bit of distance by mounting EL panel in a frame with a 20 mm gap frosted perspex and baking paper to dim the light slightlyr but i seem to get a cast in centre of image bit of detective work going on at the minute to see if i can get  to the bottom of the issue . 

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very nice, regarding the flats, i use a bit of white cotton t shirt fabric over the aperture of the scope, seems to help with evenly distributing the light and not causing funny lines or shapes 

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Bottletopburly
4 hours ago, red dwalf said:

very nice, regarding the flats, i use a bit of white cotton t shirt fabric over the aperture of the scope, seems to help with evenly distributing the light and not causing funny lines or shapes 

I have some white material stretched over panel in the frame I made , it’s probably me being paranoid probably caused more by the led lights from town 

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silentrunning

What sort of exposure times are you using for the flats Dave. Excessively short ones with a panel may catch the flicker of the panel and created a banding effects. I ensure my exposures are from 2 to 5 seconds which has necessitated the addition of a couple of layers of Opal perspex to bring the brightness down. 

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Bottletopburly
16 minutes ago, silentrunning said:

What sort of exposure times are you using for the flats Dave. Excessively short ones with a panel may catch the flicker of the panel and created a banding effects. I ensure my exposures are from 2 to 5 seconds which has necessitated the addition of a couple of layers of Opal perspex to bring the brightness down. 

About 1/20 at the minute no banding present now having tweaked panel , ivo Jager from Startools is going to have  a look at my last data set as it may be me missing something in the initial stages of Startools .

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silentrunning
1 minute ago, Bottletopburly said:

About 1/20 at the minute no banding present now having tweaked panel , ivo Jager from Startools is going to have  a look at my last data set as it may be me missing something in the initial stages of Startools .

 

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Derbyshire Dave

Great shot Dave, stunning detail and colour. Regarding lines from a flat panel, I added extra layers of white copier paper, until my exposure increased.

This seemed to eliminate the lines, which were present before.

Times I use are..0.15 second for LRGB

0.45 seconds for Ha, 1.0 seconds for Sii, 0.10 seconds for Oiii.

 

 I worked out these times by looking at the resulting image until was bright enough to clearly see the problem areas on the flats

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Mostlycloudy

Excellent tips. I've been struggling to get decent flats for ages. I've got a cheap tracing pad light that seemed to work, until you put it through DSS and it decided it needed stripes. Gave up on several experimental imaging runs because of the stripes. So I just took a set of flats, as before, but just went from 0.1 second to 2 seconds with the same ISO (let DSS do the work). This resulted in very white flats, i have no way of checking the level other than the histogram on the camera, but no stripes on the old images! 

 

Is there some windows (free) software to tell the optimum exposure for flats or even just get a maximum pixel value?

 

I have been reading through 'photographingspace.com', that has lots of tuturials and is well worth a look.

 

Cheers

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... is there some windows (free) software to tell the optimum exposure for flats or even just get a maximum pixel value? ...

 

It's probably an complete overkill but IRIS will tell you the maximum pixel value within an image and its free. It excepts some RAW formats, FITS files and the standard imaging formats - TIF, JPG, PNG etc. And it's not overbloated, about 5Mb.

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Bottletopburly
2 hours ago, Mostlycloudy said:

Excellent tips. I've been struggling to get decent flats for ages. I've got a cheap tracing pad light that seemed to work, until you put it through DSS and it decided it needed stripes. Gave up on several experimental imaging runs because of the stripes. So I just took a set of flats, as before, but just went from 0.1 second to 2 seconds with the same ISO (let DSS do the work). This resulted in very white flats, i have no way of checking the level other than the histogram on the camera, but no stripes on the old images! 

 

Is there some windows (free) software to tell the optimum exposure for flats or even just get a maximum pixel value?

 

I have been reading through 'photographingspace.com', that has lots of tuturials and is well worth a look.

 

Cheers

Nina’s free  has a flats wizard finding it a bit temperamental you need to get light source quite dim worth a look thought I sorted it then realised had wrong iso but I will have another look gives you the read out of your target ADU value  , tracer panels are side lit from one side so you don’t get an even field of illumination, there are led lights I spotted on eBay that look like they would be very good flats panels all contained in one unit.

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Mostlycloudy

I have IRIS downloaded but haven't really played with it, will give that a try, would be good to put some numbers to the 'whiteness' level. The tracer panel was purloined from our kids art box, so may not be up to the task. Most of the panels i've seen online seem very bright, or atleast they preport to be. Will have a look around.

 

Thanks

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