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Specific exposure settings for specific film and camera lens during eclipse

7 replies to this topic

#1 kur3tking

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Posted 09 October 2023 - 05:04 PM

Hello All,  I am hoping for some expertise to get going in the right direction.  I will attempt my first eclipse photos Oct. 14,2023 and use the experience to catch the big show in April 2024.

 

I plan to use the following equipment and am hoping for some exposure settings to make this October 14th a success.  If you are confident of an exposure setting as the moon starts its transit, I would like to bracket exposures from what you think is an ideal exposure for transit shots. For example;  25% coverage = 1/15th second and so I bracket 1/30th and 1/8th, then 50%, 75%, and totality.  I am in south Texas so the totality will be 100% and that may figure in exposure estimates.  Thanks for your assistance!  FYI, my Nikon D750 is not compatible with the Nikkor 1000mm.

 

2-FM3a bodies

Nikkor 1000mm f/11 reflex(set F/11 aperture)

Ektar 100 print film,  but I can put ISO 200 print in one FM3a if that increases my chance of getting some good shots

full aperture solar filter

heavy duty Benco tripod 

cable shutter release

 

Enjoy the eclipses, wishing you clear skies!



#2 SkipW

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Posted 09 October 2023 - 08:33 PM

For an annular eclipse, partial eclipses, and partial phases of a total eclipse, just set up your equipment the way you expect to use it during the event and find the best exposure first hand. Assuming no great difference in atmospheric transparency, that will probably suffice for the real thing.

 

You should use the same exposure for all the partial and annular phases, so that's easy. Just go out and take test exposures.

 

Exposure values for totality are a different matter, but there are several threads here that go into a lot of detail on that.



#3 Cajundaddy

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Posted 10 October 2023 - 12:01 AM

Here is my plan:  

ISO 200, fixed focus, f 6 @ 645mm EFL , shutter speed for best exposure on full solar disc 1hr prior,  set intervalometer for time lapse and let her rip for the entire annular eclipse.

The solar surface will always be visible and at a constant brightness.  Since the sun is the subject of the photo I see no benefit in adjusting exposure levels.  Get it right and leave it alone.   I have no interest in overall exposure balance, and some dimming effect at annularity will add drama but the subject- solar surface will be constant.  

This annular eclipse will be a very different exercise than the April 2024 Totality but mastering focus, exposure, tracking, are all relevant to both.


Edited by Cajundaddy, 10 October 2023 - 12:10 AM.

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#4 winbag4

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Posted 10 October 2023 - 08:11 AM

If photographing the total eclipse is your goal, this guide by Fred Espenak is a nice place to start: https://www.mreclips...to/SEphoto.html

 

Gordon Telepun (Solar Eclipse Timer) also has some great resources, particularly useful if you're using a glass solar filter: solareclipsetimer.com

 

For the partial phases, exposure depends on your gear and the type of solar filter you use. You might be able to get a good idea from charts, but it would be best to just test beforehand to get a nicely exposed sun disk. The exposure that you find works on an uneclipsed sun will work for all of the partial phases.

 

Totality is another animal. That's where those guides come in especially handy. Another resource I like is this exposure calculator: http://xjubier.free....seExposure.html

 

Usually the charts/calculators don't agree down to the exact exposure, but generally all agree within about a couple stops or so.


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#5 skaiser

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Posted 10 October 2023 - 10:14 AM

For the Annular , as they mentioned , test shoot with the current sun for best setting.

Main challenge will probably be getting tight focus.

Depending on your lens, if it is fairly loose in the focus mechanism , you may want to use some tape on the focus ring once it is set .

Some lenses will tend to focus drift if the lens if \s too far up or down.

Good luck



#6 kur3tking

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Posted 10 October 2023 - 11:36 AM

Thanks to All, so far it looks like if I get a initial exposure, that will hold thru out the eclipse with no need to bracket.  I have used my setup outside on a clear day, attempting to get a correct exposure but the view finder in the Nikon FM3A was so dark I could not see any exposure information.  Somehow I will have to overcome that problem to get a correct exposure setting.



#7 SteveInNZ

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Posted 10 October 2023 - 07:34 PM

Do you have any longish lenses for your D750 ?

If you use the same solar filter, set the aperture to f/11 and ISO to 100, then whatever shutter speed gives you the correct exposure on your digital will be the same for the film camera and lens.

If mid eclipse is going to be low on the horizon for your location, do your test shots at about the same time. Your exposure times won't be long enough to worry about reciprocity.

 

Steve.



#8 kur3tking

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Posted 12 October 2023 - 11:48 AM

Thanks Steve, it seems my problem is solved as my solar filter arrived for my 300mm F/4 + 2x. The filter wasn't due until after October 14 but arrived yesterday.  You idea is a good one as I can know figure the exposure for the 1000mm reflex.  Getting nervous as so far nothing but dark clouds since Tuesday.





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