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Planetary Imaging with Light Pollution Filter?

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#1 hherzy

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Posted 26 June 2022 - 02:36 AM

         I just realized that all of my images of Jupiter/Saturn/Venus were imaged with my Ha-modified camera with the IDAS LPS D1 filter.

post-205769-0-56228300-1423399839.jpeg

         I found this graph showing the spectrum of the IDAS LPS D1 filter. Im not sure how to interpret this graph or what it means? are the dips in the graph areas of the spectrum blocked by the filter? This makes sense to me as the filter is designed to block light pollution by targeting wavelengths that light pollution commonly shines at. I was thinking this filter would particularly harm Saturn, given that Saturn shines predominantly yellow/orange. On the other hand, the planets are so bright its possible they would overpower the effects of the filter? Is the incorporation of this filter in thee imaging train harming my data?

 

           Secondly, is it feasible to find proper color balance in a full spectrum modded camera? I find every image is tinted red. This is expected, but it is very difficult for me to find color balance that looks natural. For my deep-sky shots I always do a photometric color balance, giving me scientifically accurate values with almost no work. Yet I spend hours color balancing planetary shots by hand, comparing to other images online and still find myself unhappy. Is this a waste of time? I could bust out my old Nikon D3200, which isn't modified. Im not sure if I even have batteries for it still, but I could buy some if necessary.


Edited by hherzy, 26 June 2022 - 02:38 AM.


#2 ngc7319_20

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Posted 26 June 2022 - 03:20 AM

Yes dips and low areas in the graph are blocked.

 

This LPS-D1 filter will increase your exposure times on planets.  Thats probably the main down side.

 

Maybe try a UV/IR blocking filter and see if that helps with the color balance.


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#3 Tulloch

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Posted 26 June 2022 - 04:06 AM

Yes dips and low areas in the graph are blocked.

 

This LPS-D1 filter will increase your exposure times on planets.  Thats probably the main down side.

 

Maybe try a UV/IR blocking filter and see if that helps with the color balance.

Agreed, just replace the LPS-D1 filter with a UV/IR filter.


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#4 dcaponeii

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Posted 26 June 2022 - 10:57 AM

UV/IR filter.


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#5 hherzy

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Posted 26 June 2022 - 05:57 PM

Yes dips and low areas in the graph are blocked.

 

This LPS-D1 filter will increase your exposure times on planets.  Thats probably the main down side.

 

Maybe try a UV/IR blocking filter and see if that helps with the color balance.

Im a little confused about how to determine exposure time given that I am imaging sets of frames. Say I image 30fps for 30 seconds, giving me 900frames each 1/30th a second in length. 

Are you saying I would have to shoot a lower FPS so that each individual frame is longer? I didn't know it was possible to adjust fps when recording video (.mov).

 

Now that I think of it, It makes sense to me that the higher the framerate, the better, as each frame will have less atmospheric turbulence interfering over the frame. 

 

Agreed, just replace the LPS-D1 filter with a UV/IR filter.

 

UV/IR filter.

 

Thanks! Will a UV/IR filter effectively 'un-modify' my camera? If I remember right, full spectrum modification just means removal of the IR cut filter. Is this the same thing you mean by UV/IR filter? 


Edited by hherzy, 26 June 2022 - 06:21 PM.


#6 Tulloch

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Posted 26 June 2022 - 06:19 PM

Im a little confused about how to determine exposure time given that I am imaging sets of frames. Say I image 30fps for 30 seconds, giving me frames each 1/30th a second in length. 

Are you saying I would have to shoot a lower FPS so that each individual frame is longer? I didn't know it was possible to adjust fps when recording video (.mov).

 

Now that I think of it, It makes sense to me that the higher the framerate, the better, as each frame will have less atmospheric turbulence interfering over the frame. 

If you are using your Canon T3i to image the planets, the best way is to capture the Liveview stream at 5x zoom using a program like BackyardEOS. If you haven't done so already, have a look a the FAQ at the top of the forum and the link in section 4.

https://www.cloudyni...ated-june-2022/

 

Capture the planets for at least 3 minutes, section 14 of the FAQ gives more info here...

 

Thanks! Will a UV/IR filter effectively 'un-modify' my camera? If I remember right, full spectrum modification just means removal of the IR cut filter. Is this the same thing you mean by UV/IR filter? 

Basically yes. Technically you will only need an IR cut filter, but most cut UV by default as well.

 

Andrew


Edited by Tulloch, 26 June 2022 - 06:20 PM.

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