Re: [APML] Fuji NHG II 800

[Philip Perkins <philip@astrocruise.com>]

Dave,

There was a great deal of discussion about this film a little while ago - 
it should all be in the archives.  In my view this film has the most 
astonishing spectral response of any colour film that I've seen.  The 
result is very close indeed to that of a properly calibrated 
tri-colour.  See Philippe Keller's amazing Eta Carinae - here the NHG was 
used as the colour component of an LRGB:
http://www.astrooptik.com/Bildergalerie/Hyper/SchroeterKeller/EtaCarinae.JPG

We have to bear in mind that Eta Carinae is a remarkably bright 
object.  Unfortunately NHG appears to be relatively insensitive when 
compared to something like PPF - at least the Ha response is low but there 
is evidence that the broadband response (and the OIII response) are just as 
good as the best astro films.  I put together my own rudimentary comparison:
http://www.astrocruise.com/xppfvnhg.htm

This is nothing like a proper test and it is also very limited because it 
only compares an emission object (and a faint one at that).  I believe that 
NHG would fare much better on broadband objects.  In this comparison the 
NHG seems to perform quite poorly in comparison with PPF, however some 
analysis reveals that this is (probably) wholly due to the weak Ha 
response.  In other respects NHG performs very well.  Notice that the grain 
is almost identical to PPF even though this is an 800 ASA film.  In a 
proper test I believe that the broadband reponse of NHG (and the OIII 
reponse) would prove to be even superior to that of PPF.  It's a great 
shame - if only the Ha response could have been strong this film would be a 
landmark, and probably one of the best films ever produced for astro 
work.  Again, I have seen nothing come close to the OIII response.

--Philip


>I grabbed a roll of this in 120 format ...
>
>Does anyone have experience with this film ???
>
>(is there a 35 mm equivalent ???)



Philip Perkins - philip@astrocruise.com
Wiltshire UK & Luberon France
Astrocruise - http://www.astrocruise.com


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