Calculating Multiple Exposures at Night with the Moon?

JDW22 · Dec 20, 2017

I very much admire the work of fine art photographer Mark Klett. One of his projects, "Time Studies", both inspires and intrigues me. I've provided a couple of links below to images on Mark's website that show two of my favorites from this project. I'm very interested in trying to capture a similar image using my Hasselblad and some FP4+. I'm neither proficient nor experienced at multiple exposure photography - especially at night with a moon in the image.

My primary question is; how would I go about calculating the appropriate individual exposures?

Any help, recommendations, references or other constructive comments are sincerely appreciated.

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wiltw · Dec 20, 2017

When the images of the moon itself do not overlap (each image of the moon stands alone) each needs to have 'proper exposure' in EACH of the images used to make the composite image, i.e. 'Moony 11, 1/ISO f/11

Sirius Glass · Dec 20, 2017

I started a thread recently on that subject and the 500 rule. Many added in more accurate ways to get the right exposure. Do some searching on this website.

tedr1 · Dec 20, 2017

It seems to me there are several ways to go about this. The concept given above "Moony 11" is a good place to begin. You might want to make some test exposures bracketing around this value for various altitudes of the moon above the horizon at different times of night, and for different sky conditions, clear and hazy.

Obtaining star trails requires very long exposures, minutes to hours. Neutral density filters may be involved. I believe the techniques for star trails are well proven and a websearch would turn up a lot of detail.

On the other hand the moon needs fractions of a second exposures, 1/125th at f11 using FP4.

Is the final image to be made by compositing multiple frames or by sequential exposures of a single frame?

BrianShaw · Dec 20, 2017

Check out Kit Courter’s site. He has info that might help.

http://home.earthlink.net/~kitathome/LunarLight/

wiltw · Dec 20, 2017

JDW22 said:
My primary question is; how would I go about calculating the appropriate individual exposures?

Any help, recommendations, references or other constructive comments are sincerely appreciated.

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My earlier comment about Moony 11 assumes you want some detail in the moon, yet both images above are TOTALLY LACKING...grossly overexposed. You need no recommendations from us, to achieve that! Simply shoot however you want, and cover the lens with lens cap in between moon positions.

jonasfj · Dec 21, 2017

wiltw said:
When the images of the moon itself do not overlap (each image of the moon stands alone) each needs to have 'proper exposure' in EACH of the images used to make the composite image, i.e. 'Moony 11, 1/ISO f/11

You mean the Looney 11 rule?

f/11, 1/125s, ISO 100

markbarendt · Dec 21, 2017

The normal exposure for the moon if you want to get good detail is easy, all you need to know is what light it’s in; for the bright side that is always full sun.

Sunny 16 with FP4 gives us f/16 at 1/125 or an equivalent. That is the normal exposure at any given point to get a sharp detailed moon onto the film appropriately.

The streaks are made simply with a longer exposure, the length of the streaks is determined by shutter open time. Aperture remains constant.

JDW22 · Dec 21, 2017

Thank you all for the kind comments and suggestions. You've given me a terrific starting point. The first full moon of 2018 will provide a terrific opportunity to experiment and learn.

wiltw said:
My earlier comment about Moony 11 assumes you want some detail in the moon, yet both images above are TOTALLY LACKING...grossly overexposed. You need no recommendations from us, to achieve that! Simply shoot however you want, and cover the lens with lens cap in between moon positions.

wiltw - While I haven't asked Mr. Klett directly about his exposure strategy, I don't believe he was trying to get detail in the moon. That being said, I'd like to create similar images to Mr. Klett's with some moon detail.

JDW22 · Dec 21, 2017

tedr1 said:
It seems to me there are several ways to go about this. The concept given above "Moony 11" is a good place to begin. You might want to make some test exposures bracketing around this value for various altitudes of the moon above the horizon at different times of night, and for different sky conditions, clear and hazy.

Obtaining star trails requires very long exposures, minutes to hours. Neutral density filters may be involved. I believe the techniques for star trails are well proven and a websearch would turn up a lot of detail.

On the other hand the moon needs fractions of a second exposures, 1/125th at f11 using FP4.

Is the final image to be made by compositing multiple frames or by sequential exposures of a single frame?

Terrific question tedr1. I intend to create my images by sequential exposure of a single frame. In your opinion or experience, would that intent change my exposure calculation and/or strategy?

macfred · Dec 21, 2017

JDW22 said:
Terrific question tedr1. I intend to create my images by sequential exposure of a single frame. In your opinion or experience, would that intent change my exposure calculation and/or strategy?

The simplest way to correct your calculation when doing multiple exposures is adjusting your ISO - using ISO 100 film and you want to do a double exposure, set your ISO to 200 for metering - four exposures metering with ISO 400, ...
Regarding the 'Mooney 11' I would try 2 exposures with f/11 1/250, 4 exposures with f/11 1/500, ...

Jim Jones · Dec 21, 2017

markbarendt said:
. . . Sunny 16 with FP4 gives us f/16 at 1/125 or an equivalent. That is the normal exposure at any given point to get a sharp detailed moon onto the film appropriately. . . .

At first glance this would seem correct, because both Earth and Moon are illuminated by the Sun and at about the same distance from it. However, the surface of the Moon is darker than a typical earth landscape. Also, at night we perceive the full Moon as being almost a blinding white. Therefore, one or more stops exposure is need for the Moon than for Earth landscapes.
There are advantages in either double exposing on film or compositing two images in the processing in addition to getting the exposure right. The Moon can be captured with a long lens, increasing its size in the photograph. Any foreground detail in the composite can be shot in daylight, just as "moonlit" movies have been done for a hundred years. The moon need never be visible for the foreground in a composite. Some photographers have even carried a spare SLR with a full roll of film of properly exposed moon shots rewound so interesting foreground information can be composited in-camera.

markbarendt · Dec 21, 2017

Jim Jones said:
At first glance this would seem correct, because both Earth and Moon are illuminated by the Sun and at about the same distance from it. However, the surface of the Moon is darker than a typical earth landscape. Also, at night we perceive the full Moon as being almost a blinding white. Therefore, one or more stops exposure is need for the Moon than for Earth landscapes.
There are advantages in either double exposing on film or compositing two images in the processing in addition to getting the exposure right. The Moon can be captured with a long lens, increasing its size in the photograph. Any foreground detail in the composite can be shot in daylight, just as "moonlit" movies have been done for a hundred years. The moon need never be visible for the foreground in a composite. Some photographers have even carried a spare SLR with a full roll of film of properly exposed moon shots rewound so interesting foreground information can be composited in-camera.

There are lots of caveats that can affect an exposure decision, my way gets the moon on the film curve in a way that allows it to be printed sharp and detailed, in the print itself the moon can be done dark or light at the printers whim.

Two possible downsides of adding exposure are more ambient light visible in the foreground and more haze in the sky.

One possible upside of more exposure are more star trails.

If a specific length for the star trails is expected then the exposure time is known/fixed, if the film has been defined as in this case with FP4 then the film speed is known, the only variable left is aperture.

John Koehrer · Dec 21, 2017

Didn't A. Adams use that to base his exposure for "Moonlight over Hernadez"? Worked for him.
He never simplified things but preferred using candelas, lumens of furlongs per fortnight?

JDW22 · Dec 23, 2017

To drill down on this discussion a little further, I don't consider Mr. Klett's two images (see links in my original post) to be photographs of the moon. Instead, I consider them photographs of the desert or saguaro cactus that includes the moon via multiple and long exposures. As I noted in my original post, this is from Mark's project "Time Studies". Accordingly, I interpret his intent by capturing multiple moons to moon/star trails as a way of illustrating the passage of time. Therefore, I surmise that Mark was not trying to photograph the moon with any specific detail. In the end, this is only conjecture on my part as I've never spoken to Mr. Klett directly about his intent. That aside, I am trying to improve my understanding of this unique exposure scenario. Like the photograph in this link from Mark's website (Dead Link Removed), the moon is definitely "grossly overexposed" and "totally lacking" in any detail. However, the saguaro is given sufficient exposure to show a reasonable amount of detail, which I believe makes the photograph work much better than it otherwise might have been if he had been exposing primarily to achieve good detail in the moon face.

What am I missing? Thoughts...

Jim Jones · Dec 23, 2017

JDW22 -- Of course you are right. Mark Klett's photographs seem to have more meaning for him than for some of the rest of us. We shouldn't expect them to be fine examples of the appearance of just the moon. He captures scenes at night well. To me the moon is merely a distraction.

wiltw · Dec 23, 2017

JDW22 said:
Terrific question tedr1. I intend to create my images by sequential exposure of a single frame. In your opinion or experience, would that intent change my exposure calculation and/or strategy?

Only when the images' areas of illumination overlap one another. Dark + Light = light , Medium + Medium = light, Medium + Medium + Medium = Medium = blown out

wiltw · Dec 23, 2017

JDW22 said:
To drill down on this discussion a little further, I don't consider Mr. Klett's two images (see links in my original post) to be photographs of the moon. Instead, I consider them photographs of the desert or saguaro cactus that includes the moon via multiple and long exposures. As I noted in my original post, this is from Mark's project "Time Studies". Accordingly, I interpret his intent by capturing multiple moons to moon/star trails as a way of illustrating the passage of time. Therefore, I surmise that Mark was not trying to photograph the moon with any specific detail. In the end, this is only conjecture on my part as I've never spoken to Mr. Klett directly about his intent. That aside, I am trying to improve my understanding of this unique exposure scenario. Like the photograph in this link from Mark's website (Dead Link Removed), the moon is definitely "grossly overexposed" and "totally lacking" in any detail. However, the saguaro is given sufficient exposure to show a reasonable amount of detail, which I believe makes the photograph work much better than it otherwise might have been if he had been exposing primarily to achieve good detail in the moon face.

What am I missing? Thoughts...

You are not missing anything...it is entirely the rationale behind my prior comment about exposing HOW YOU WANT, to meet your artistic vision of the final result.
OUR recommendations for exposure, in view of you having some artistic vision already in mind, is meaningless unless you first tell us YOUR artistic vision at the time of shooting!

markbarendt · Dec 23, 2017

JDW22 said:
What am I missing? Thoughts...

As has been said, exposure is cumulative, but it is also local. I very often think about each subject separately. The challenge is to get them all on the same negative.

It isn’t really about getting it on the negative, when designing a shot you need to think about the exposure for each subject and how you are going to get them on the paper.

For example the moon in the examples shown is underexposed on the print/positive. Depending a bit on what film was used it is probably very possible to burn in the moon on the print to get a sharp detailed moon if that was a the photographer’s intent.

Getting the foreground right isn’t tough either if you apply a little ZS thought and placement or a bit of artificial light.

Don’t get hung up on getting all the placements perfect for the print on the negative.

JDW22 · Dec 27, 2017

Sorry for my delayed reply. I also apologize for not clearly explaining my vision of a final photographic result. Maybe that is simply a reflection of my poor communication skills, or an expression of my uncertainty? I had hoped that providing the links to Messrs. Klett's images would help.

So let me try this statement; my vision is to find a balance of multiple exposures on a single frame of 120 film where where the moon and foreground landscape (i.e. cactus, building, etc) are adequately exposed. By "adequately" I mean sufficient exposure for anyone viewing the photograph to determine what is in the frame, but not perfect exposure. I.E. no details in the moon face are necessary. Like Mr. Klett, I'm looking for a way of showing the passage of time on a single negative. I hope that is more helpful explanation, but I'll certainly understand if I've only further muddied the water. Happy Holidays all!

markbarendt · Dec 27, 2017

JDW22 I think there are a couple points you are missing.

One is that you define what is adequate or perfect. Perfect exposure is simply 'the exposure you want/need' for a given subject.

Two is that a negative is just an intermediary storage medium, what gets printed from a negative is completely at the whim of the person doing the printing. Here's an article and video that has an example of what I'm getting at, https://petapixel.com/2016/06/24/making-ansel-adams-famous-image/ specifically at about 5:50 on the video but the whole thing is relevant.

All negatives require manipulation to make them into positives (print contrast, exposure, developing, burning/dodging, bleaching, whatever... There are no exceptions to that rule: sometimes the manipulations are done thoughtfully by the person printing or done with artificial lighting when shooting the shot, sometimes they are simply defaults chosen by others; one way or another all shots from negatives are manipulated to get a positive.

The photo example you provided with the cactus actually appears to be a mid-day shot of the sun, not the moon. The camera settings will be wildly different from the moon shot question you led with. The process of choosing exposure is the same though. In any shot you need to decide how to get each of your subjects on to the negative then separately you need to figure out how to place them in the positive.

For the examples you have provided the time that the shutter was open is knowable because of the length of the trail. Using any given film you please the sensitivity (ISO) is also known. The only variables left in the field are the aperture setting, lens filters, and artificial lighting.

wiltw · Dec 28, 2017

As already pointed out by markbarendt, " ...you define what is adequate or perfect. Perfect exposure is simply 'the exposure you want/need' for a given subject."

JDW22 said:
my vision is to find a balance of multiple exposures on a single frame of 120 film where where the moon and foreground landscape (i.e. cactus, building, etc) are adequately exposed.

But your description does not communicate just how bright/dark the foreground landscape needs to be to be considered 'adequately exposed' by you...is it 'bright' or is it 'barely visible' or somewhere along the continuum in between those two extremes?
As exemplified by this series of 3 shots just taken tonight via an LED streetlight (but with a spotlight from my house supplementing what the LED streetlight provided).
Exposures at ISO 25600, f/2.8 aperture, and between 1/8 and 1/30 for shutter speed:

What was my definition for 'adequately exposed', where was the brightness of the surrounding area as envisioned by me before I shot?... represented by 1, 2, or 3 or somewhere in between 1 and 3 (but not '2')?!
Perfect exposure is simply 'the exposure I want/need' for this subject in this lighting'.
Do you know where I wanted the exposure to land, so that you could start to recommend an exposure for me to use?!

Even with a quantitative description to try for, in your case, there is the additional variable of the fullness of the moon having a strong bearing on the light striking the foreground...less exposure needed for a full moon than for a new moon.

Lastly, once you know the final brightness of the composite that you are striving to achieve, you need to divide the final result by the number of exposures in the composite...if 1/20 was the brightness you were striving for in a single exposure, then 6 exposures means each needs to be 1/6 of 1/20, or 1/120...since 6/120 = 1/20

Calculating Multiple Exposures at Night with the Moon?

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