Re: [APML] Best 120 color film?

[Philip Perkins <philip@astrocruise.com>]

Matt,

I have uploaded the scans I did for Philipp Keller about a year ago.  He 
imaged B33 on 120 format NHG and Optima from Namibia under very similar 
conditions:

http://www.astrocruise.com/nhgvopt/b33_nhg.jpg

http://www.astrocruise.com/nhgvopt/b33_opt.jpg

They fit exactly the results that I got from these two films.  This is why 
I was surprised at the reports of the poor red respons with the Optima.  If 
anything, my impression is that the red is a little over strong.  There is 
also a tendency for colours to posterize with Optima.

The grain is quite a bit larger in the NHG result but this doesn't show in 
these greatly scaled down versions.  They were from 120 format negatives 
scanned at 2571 dpi.

I did a test of NHG myself and got a very similar result.  NHG is an 
excellent film with just one exception:  the Ha response is too 
weak.  Without that problem it would probably be a killer astro film - see 
below:

http://www.astrocruise.com/xppfvnhg.htm

(I apologise for not asking Philipp's permission to upload these scans, 
however I feel sure that he will not mind - whatever the film results, they 
both show Philipp's extraordinary skills as an optician (he makes these 
telescopes) and as an imager)

--Philip



At 21:33 08/12/01 -0500, you wrote:
>Loke,
>
>Agfa Optima 400 is suppose to have poor red response, even when hypered.
>
>Philip Perkins says that Fuji NHG II 800 lacks red response, even when 
>hypered, but Philipp Keller likes NHG II 800.
>In any case, I think it has to be hypered for optimal response.
>
>AFAIK PPF 400 has the best color response of any MF film ever made, even 
>unhypered, but it is no longer made, and remaining stocks are exhibiting 
>larger grain.
>
>E200 has limited dynamic range, so bright stars are larger with less 
>color. Its blue response is not as good as its red response. I find that 
>E200 records H-alpha nebulosity as orange and flat. I think E200 does 
>alright for wide-field, but Provia 100F may be better.
>
>Matt



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


--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
             Unsubscribe at <majordomo@seds.org>