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New Film - Fuji Acros II

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29 replies to this topic

#26 canondslr

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Posted 17 March 2020 - 02:15 PM

Thats great to hear it is true Acros, and that it may be an improvement with hydrogen clouds. Really looking forward to your tests! 

 

I'll try to add new images too, as I gain more experience with my new mount!

 

Thomas



#27 Todd N

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Posted 19 March 2020 - 12:11 PM

https://www.flickr.c...eposted-public/

 

I tested Acros II extended red sensitivity. It's response to H-alpha is slight and I wouldn't expect any significant contribution to the recorded image. I planned on comparing it to old Acros but there wasn't enough film left to load in the camera.

 

Red astronomy light(dual LED) on lowest setting, pointed towards room corner on end table.

Vivitar SLR/50mm lens @f/5.6, 4min exp. Lumicon Night Sky Hydogen Alpha Filter(W92)

HC-110 dil. H(1/63)

Comparison with hypered Fomapan 400 that has good H-alpha sensitivity.

 

 

Todd

 


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#28 Nightfly

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Posted 19 March 2020 - 05:52 PM

This is excellent Todd! 

 

Nice to have this test done.   Agreed that the Foma 400 worked the best here according to your testing.  That the new Acros recorded anything through the red filter satisfies my curiosity. 

 

My guess is the response from the original Acros (through the filter) would have been just short of blind.  This suggests that bright emission nebulae will be handily recorded, with more subtle emissions being more evasive.  This will be an improvement over Acros I which only recorded what the eye sees, primarily the OIII emissions. 

 

I appreciate you doing the tests.  Nice work with the hypered Foma as well.  



#29 SMigol

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Posted 03 April 2020 - 05:12 PM

If I remember the datasheet for the old Acros, proper exposure through a wratten #25 filter was +8 stops.  

 

I purchased a few rolls and will try on the summer sky when I get the chance.



#30 Nightfly

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Posted 03 April 2020 - 07:23 PM

Stephen,

 

Smoke 'em if you got 'em.....

 

There is a distinctive "bump" in the red spectrum on the new Acros II.  I'm curious to find out.....

 

I've got some trees to cut in order to catch southern Sagittarius this season.  With the pandemic I've got nothing but time......




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