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Canon EOS Ra star problems

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#601 DJE44

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Posted 17 October 2020 - 04:09 PM

First time using my Ra in a dark sky site.  Pretty disappointing with the red flaring on brighter stars.

 

Sigma Art 50mm f/1.4 DG HSM at f/2, single 15s sub (cropped).

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Edited by DJE44, 17 October 2020 - 04:11 PM.


#602 DJE44

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Posted 17 October 2020 - 04:21 PM

Unstretched / uncropped:

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#603 SandyHouTex

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Posted 17 October 2020 - 07:21 PM

So far in this thread, this only occurs with certain imaging trains, and can be mitigated with an Astronomik clip-in filter.  Either the L-1, L-2, or L-3 depending on how much IR you want.


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#604 Nikon Guy

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Posted 17 October 2020 - 11:00 PM

First time using my Ra in a dark sky site.  Pretty disappointing with the red flaring on brighter stars.

 

Sigma Art 50mm f/1.4 DG HSM at f/2, single 15s sub (cropped).

post-205521-0-89136500-1602969086_thumb.

 

 

So far in this thread, this only occurs with certain imaging trains, and can be mitigated with an Astronomik clip-in filter.  Either the L-1, L-2, or L-3 depending on how much IR you want.

Wow !!!!! 

So even after you shill out $2,500, for a purposely built "Astro-dSLR",  you still need to spend even more money, on another filter, to get it right ?

The sad part is, it's going to effect the people the camera was designed for, the most. Casual photographers wanting to try there hand at AP, using shorter fl, fast lens.


Edited by Nikon Guy, 17 October 2020 - 11:09 PM.

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#605 alan.dang

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Posted 17 October 2020 - 11:37 PM

So even after you shill out $2,500, for a purposely built "Astro-dSLR", you still need to spend even more money, on another filter, to get it right ?


Yes, if flares bother you on your optical setup, you need to block IR. It’s the only purpose-built Astro DSLR with dust reduction, a return policy if you are in the US, and RF mount capability.

It works well with a RF 85/1.2, RF 15-35/2.8 and EF 400/2.8. It works well with the AP Traveller 105 and TEC 110FL.

https://amazingsky.n...-eos-ra-camera/

Definitely not the right choice for everyone. The Sigma Art lenses really struggle with the EOS Ra. The RF 70-200/2.8 is not very good either. But the RF 15-35 and 85 seem to work well.
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#606 sharkmelley

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Posted 18 October 2020 - 02:36 AM

So far in this thread, this only occurs with certain imaging trains, and can be mitigated with an Astronomik clip-in filter.  Either the L-1, L-2, or L-3 depending on how much IR you want.

You can't assume the L1 filter works just because the L2 filter works.  The L2 filter has been tested but the L1 filter has a wider bandpass than the L2 and it's quite possible it doesn't block all the wavelengths implicated in the EOS Ra reflections.

 

Mark


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#607 SandyHouTex

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Posted 18 October 2020 - 12:56 PM

Wow !!!!! 

So even after you shill out $2,500, for a purposely built "Astro-dSLR",  you still need to spend even more money, on another filter, to get it right ?

The sad part is, it's going to effect the people the camera was designed for, the most. Casual photographers wanting to try there hand at AP, using shorter fl, fast lens.

As I have pointed out before, many DSLRs, MILCs, and even dedicated astro cameras have reflection issues like this.  Take a look at some Hubble photos with a bright star in the field.  Huge halos.

 

A couple of years ago there was a mega-thread in the ccd forum about reflections with an ASI1600 monochrome camera and some ZWO LRGB filters.  The fix was to get some Astrodon filters.  Then the Astrodons had cleanliness issues, and on, and on, ad nauseum.


Edited by SandyHouTex, 18 October 2020 - 12:59 PM.


#608 SandyHouTex

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Posted 18 October 2020 - 01:01 PM

You can't assume the L1 filter works just because the L2 filter works.  The L2 filter has been tested but the L1 filter has a wider bandpass than the L2 and it's quite possible it doesn't block all the wavelengths implicated in the EOS Ra reflections.

 

Mark

True statement.  I bought a L-2 in case I have issues with my Ra.


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#609 alan.dang

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Posted 18 October 2020 - 06:19 PM

True statement.  I bought a L-2 in case I have issues with my Ra.

Out of curiosity, have you had a chance to try any of your gear from "Astro-Physics to Zeiss" to identify other good matches?

 

I've not had many cooperative nights for imaging so I haven't had a chance to test the Leica 180/3.4 which is corrected into IR.



#610 SandyHouTex

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Posted 18 October 2020 - 07:07 PM

Out of curiosity, have you had a chance to try any of your gear from "Astro-Physics to Zeiss" to identify other good matches?

 

I've not had many cooperative nights for imaging so I haven't had a chance to test the Leica 180/3.4 which is corrected into IR.

No unfortunately.  I need to get away from my neighbors who must be skeered of the dark with all the lights they put up.  One guy catercorner from me just got done putting lights under the eaves of his house all the way around.



#611 galacticinsomnia

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Posted 19 October 2020 - 06:35 PM

So far in this thread, this only occurs with certain imaging trains, and can be mitigated with an Astronomik clip-in filter.  Either the L-1, L-2, or L-3 depending on how much IR you want.

I'm glad you brought that up.  On Point.



#612 DJE44

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Posted 19 October 2020 - 06:38 PM

Yes, if flares bother you on your optical setup, you need to block IR. It’s the only purpose-built Astro DSLR with dust reduction, a return policy if you are in the US, and RF mount capability.

It works well with a RF 85/1.2, RF 15-35/2.8 and EF 400/2.8. It works well with the AP Traveller 105 and TEC 110FL.

https://amazingsky.n...-eos-ra-camera/

Definitely not the right choice for everyone. The Sigma Art lenses really struggle with the EOS Ra. The RF 70-200/2.8 is not very good either. But the RF 15-35 and 85 seem to work well.

I’ve seen other Art lenses look a lot less worse than mine. Perhaps it’s because I shot wide open. Or the CLS clip filter?

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Edited by DJE44, 19 October 2020 - 06:41 PM.


#613 galacticinsomnia

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Posted 19 October 2020 - 06:38 PM

Wow !!!!! 

So even after you shill out $2,500, for a purposely built "Astro-dSLR",  you still need to spend even more money, on another filter, to get it right ?

The sad part is, it's going to effect the people the camera was designed for, the most. Casual photographers wanting to try there hand at AP, using shorter fl, fast lens.

When you are buying a tool to increase the bandwidth of light galthering capabilities to the sensor, it is up to the user to limit the bandwidth, which is the purpose of the tool. 



#614 Kevin_A

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Posted 20 October 2020 - 07:00 AM

No unfortunately.  I need to get away from my neighbors who must be skeered of the dark with all the lights they put up.  One guy catercorner from me just got done putting lights under the eaves of his house all the way around.

If I had a neighbor like that I would play music outside all night long until they came over to complain.... then make them a deal! hahaha

Most of mine are good but you always have one who has to ruin it by making it daytime outside while they sleep...jeeez!


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#615 SandyHouTex

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Posted 20 October 2020 - 09:41 PM

I have been wanting to post a Hubble pic to show the halos it produces.  Here’s one.  As you can see it even has asymmetric halos, and it cost $4.7 billion.

 

 

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Edited by SandyHouTex, 20 October 2020 - 09:43 PM.


#616 ozbastion

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Posted Today, 07:01 AM

Hi Alan

 

I think I have read all of the posts though I couldn't quite find any references to all of the below lens combinations. In particular, the RF 70-200- is the inclusion here based on your own experience or is it from another user here?

 

 

 

Known good optical combinations:

Canon RF 85 1.2L

Canon nFD 200mm f1.8L

Canon EF 200mm f/1.8L

Canon EF 400mm f/2.8L IS III

TEC APO 110FL

 

Known bad optical combinations

Sigma Art 85mm f1.4 

Sigma Art 35mm f1.4

Sigma Art 105mm f1.4

Canon RF 70-200/2.8L 

Canon EF 200mm f/2.8

Canon EF 300mm f/2.8 IS II

Astro-Physics 92 Stowaway f/6.65 with 0.8x reducer




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