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Astrophotography and Sketching >> Film Astrophotography

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SMigol
sage


Reged: 07/30/10

Loc: California, USA
Using Light Pollution Filters with Film?
      #6089344 - 09/19/13 03:27 AM

OK so I'm going to finally get my 67 out to the field and shoot some stars and possibly some nebula.

I have a big IDAS filter for going on a camera lens. Is it worth using for film? I also have UV IR, Haze 1, and Yellow Y2 filters. I understand that the Yellow is standard for star fields.

I have some older E200, new Provia 400 and Velvia 100, and will get some Acros 100. Only planning to shoot the E200 and Acros unless it would be better to use the Provia/Velvia.

Thanks,

Stephen


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Michal1
sage


Reged: 07/25/10

Loc: Czech Republic, Central Europe
Re: Using Light Pollution Filters with Film? new [Re: SMigol]
      #6089378 - 09/19/13 05:04 AM

There is nothing more reliable than to shoot a few comparison photos with and without the filter. The benefit of the filter will depend on the amount of light pollution at the place you photograph. At my site, which is about grade 4 on the Bortle scale, there are only minor gradients caused by light pollution visible on the pictures. Personally, I don't like even digital images taken with light pollution filters, because the stars lose their natural colors and get green.

Edited by Michal1 (09/19/13 07:37 AM)


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SMigol
sage


Reged: 07/30/10

Loc: California, USA
Re: Using Light Pollution Filters with Film? new [Re: Michal1]
      #6089751 - 09/19/13 11:16 AM

Thanks for the idea.

The location I'm going to is Lake San Antonio in California, which is on the border between a black and blue zone:


There are only slight light domes.

While I don't have the luxury of being able to do comparison shots while in the field, I can take a bunch of notes for future use.

Sounds like leaving the light pollution filters off will be best. I'll just use the haze/yellow filter on black and white. Color shifts can be corrected in post, so I'm not too worried about star color.


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Nightfly
Pooh-Bah


Reged: 06/20/07

Re: Using Light Pollution Filters with Film? new [Re: SMigol]
      #6090665 - 09/19/13 09:26 PM

Not sure if the Haze-1 will do much. I recommend the Haze-2A for E200 and Acros. It will tighten up the star images and reduce the blue sensitivity of both films. Not sure about reduction of LP.

A Y2 can be used with Acros to tighten star images and will add a half stop to your exposures as well as increase contrast slightly. Not sure I would use it. You might try it as it will tighten star images with the Takumar 300 if you use that one. Acros is very blue sensitive.

Use your E200 if it is still good. Provia 400X is good, but not as red sensitive. Push your E200 one stop and with your skies as indicated I would use f/4 for 20-30 minutes or f/4.8 for 40-50 minutes. Longer lenses should use f/5.6 for 50-60 minutes. Your mileage may vary.

With Acros developed in Xtol 1:1 I've shot the brighter areas of the Milky Way at f/4 - 5.6 and 30-45 minutes with good results.

Post 'em when you get 'em.


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SMigol
sage


Reged: 07/30/10

Loc: California, USA
Re: Using Light Pollution Filters with Film? new [Re: Nightfly]
      #6122434 - 10/07/13 01:02 PM

I'm back from the trip and will be sending in the film for developing.

I'm sending the E200 with instructions to push 1 stop. I saved one last frame to take a picture of a color chart. That should help balance colors in the final images. I exposed that color chart at standard settings, so I'm not sure how the push will effect it - probably blow it out and render it useless.

Should the ACROS be pushed? I exposed at the settings you suggested: F4 at 40 minutes on the 165mm.

Back to the topic:

It appears that using a LPR filter with E200 is a good thing if you can balance the colors in post production.

Here are some examples I found on the web:
http://www.af9y.com/tokai.htm
http://www.webalice.it/m.piccinini/deepsky/orion.htm

Based on the information on these links, I'll try a session at my local site with E200 with the IDAS filter - probably this winter so that there's enough duration of the darkness to use a whole roll in an evening.


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Chuck Hards
Post Laureate
*****

Reged: 05/03/10

Loc: The Great Basin
Re: Using Light Pollution Filters with Film? new [Re: SMigol]
      #6125058 - 10/08/13 02:13 PM

It's been a while, but I did try a broadband LPR filter when I shot Hale-Bopp. Using commercial C-41 processing (Fuji 400 & 800) and commercial printing, the color never seemed to come out right, even when I included a color calibration shot as my first frame. I eventually abandoned the filter and drove another 30 miles to put the bulk of the light pollution behind me.

I was a photo lab tech and custom color printer for 5 years way back when.


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