What is the exposure for predawn Hawaiian lava flow?

[Sirius Glass]

matrix metering and done!

There is too much black background to do that. Hence the question.

 

[Sirius Glass]

I would take an incidental meter reading and bracket my exposures at one stop increments and since it's negative film, that should produce at least a few usable negatives.

This will be done predawn so an incident reading will be of the boat in darkness.

 

[Sirius Glass]

Can you chimp with a cell phone camera and check the exposure readings and extrapolate from that?

First of all I could never find a good chimpin' class. Second the cell phone camera does not include the equivalent film speed, shutter speed, nor the f/stop. Third when I tried the cell phone during the total eclipse the results were so overexposed it turned night into day. A cell phone camera is like taking a knife to a gunfight. The big time photographers do not use cell phone cameras they shoot film.

 

[wiltw]

There seems to be a fundament lack of comprehension of the issues involving shooting lava at night on a boat. So let me substitute an electric light bulb with visible filaments in lieu of the lava, and put that light into several very different ambient light conditions, and take photos.

1. Light filament measures (with reflected light one-degree spot meter) ISO 100, 1/4000 f/11
2. Ambient light in shot 1 measures ISO 100, 1/30 f/2.8 with incident meter (indoors)
3. Ambient light in shot 2 measures ISO 100, 1/100 f/16 with incident meter (Sunny 16)
4. Ambient light in shot 3 measures ISO 100, 1/2 f/2.8 with incident meter (dimly lit indoors)

All shots below were exposed at a fixed ISO 100, 1/500 f/11 (-3EV below what was metered for the filament):

If you are interested in seeing the filament (or lava) glowing red hot, you do not shoot it as suggested per bullet 1 -- or the spotmeter reading of the lava!
If you are interested in seeing any surrounding detail (detail which is not the filament itself) it is very dependent upon the brightness of the surrounding AND the shutter speed and aperture suitable for that light level
The reading on the incident meter measurement has no direct bearing on the measurement of the filament! The reading on the incident meter measurement has no direct bearing on the measurement of the lava!
If I adjust my exposure for ambient light situation, I screw up my exposure of the filament or the lava!

• If you SHOOT FOR THE FILAMENT, there is NOTHING than you can do to render the surroundings visible/invisible, you are at the mercy of the RELATIVE DIFFERENCE in brightness between the filament and the surroundings.
• If your primarly interest is to capture glowing red lava, there is NOTHING than you can do to render the surroundings visible/invisible, you are at the mercy of the RELATIVE DIFFERENCE in brightness between the LAVA and the SURROUNDINGS.

 

[Sirius Glass]

There is not much detail illuminated by the molten lava. It is mostly freshly cooled lava which is very black. The question is once metered with spot how much does the lens need to be opened to get the lava in the correct Zone.

 

[wiltw]

There is not much detail illuminated by the molten lava. It is mostly freshly cooled lava which is very black. The question is once metered with spot how much does the lens need to be opened to get the lava in the correct Zone.

It ALL DEPENDS!!!

• How much darker or brighter than 18% tonality is the lava?
• How much darker or brighter than 18% tonality DO YOU WANT the lava TO APPEAR in the photo?

For example, if the lava is fairly cool and is -1EV darker than 18% tonality AND you want the lava to be brighter than 18% tonality in the photo by +1EV, then you have to tell the meter that you want EC = +2EV
Or, if the lava is fairly hot and is +1EV brighter than 18% tonality AND you want the lava to be brighter in the photo by +1EV, then you have to tell the meter that you want EC = +1EV

FUNDAMENTAL PRINCIPLE: Whatever you aim the meter at, it will suggest to you an exposure which will record that target area as 18% gray!

BTW, 'molten lava' is orangish glowing, and 'cooling lava' is hardening and blackish

 

[mjork]

This discussion motivated me to post my lava flow photos online. I was in Hawaii in July and took photos from the official viewing area (reached by bike ride). Though that was in the evening with Velvia 50 slide film and a tripod. The first photo was taken when it just became dark enough to clearly see the lava. At those light levels you will probably be OK on a boat with ISO 400 film. Having a lens with image stabilization will be an extra bonus.
The second photo is from the end of my shooting session when the brightness of the sky and the lava matched pretty well. That would be too dark for handheld shooting with a long lens.

For metering, I used the partial metering mode of my Canon EOS camera (that's a somewhat larger measuring area than spot metering tends to be). For the first photos, I measured the white smoke cloud and placed that at about +1. And then later when it was darker, I measured the lava glow and also placed it at about +1. My concern with slide film was not to blow out the sky. So I also measured that to figure out how much and what area of the sky was safe to include.

 

[Sirius Glass]

This discussion motivated me to post my lava flow photos online. I was in Hawaii in July and took photos from the official viewing area (reached by bike ride). Though that was in the evening with Velvia 50 slide film and a tripod. The first photo was taken when it just became dark enough to clearly see the lava. At those light levels you will probably be OK on a boat with ISO 400 film. Having a lens with image stabilization will be an extra bonus.
The second photo is from the end of my shooting session when the brightness of the sky and the lava matched pretty well. That would be too dark for handheld shooting with a long lens.

For metering, I used the partial metering mode of my Canon EOS camera (that's a somewhat larger measuring area than spot metering tends to be). For the first photos, I measured the white smoke cloud and placed that at about +1. And then later when it was darker, I measured the lava glow and also placed it at about +1. My concern with slide film was not to blow out the sky. So I also measured that to figure out how much and what area of the sky was safe to include.

Thank you. I will be in the dark most of the time in the boat and we stay out until after sunrise.

 

[Craig75]

https://m.dpreview.com/news/0338476846/shooting-kilauea-volcano-part-3-at-sea

Digital i know but you might still find it interesting

 

[Sirius Glass]

https://m.dpreview.com/news/0338476846/shooting-kilauea-volcano-part-3-at-sea

Digital i know but you might still find it interesting

Thank you. We have prepaid for the boat trip, so I hope there is lava flowing otherwise will have wasted money.

 

[WilmarcoImaging]

I would spot meter with the zoom/telephoto lens and give 2 stops more exposure. As mentioned above, potential for resultant slow shutter speed should be noted.

 

[John Koehrer]

The Exposure Value is equal to one tenth the airspeed velocity of an unladen swallow....

So If I understand this the EV would then be higher than the airspeed of a swallow lugging a 100# pack, 200 rounds of 5.56 ammunition plus weapon.
IE: a laden swallow.

 

[DWThomas]

Use supplementary lighting -- back in the day we had Lava Lamps!

 

[Jim Jones]

If I desperately wanted to photograph lava at night and had considerable money already invested in the opportunity, I would also invest in a modest DSLR with good high ISO performance, and adjust the ISO as necessary to get a decent exposure. Do learn how to use the DSLR before departing on such an opportunity. Film has its place, but so do modern cameras. I grew up in farming country when horses were used more than tractors and combines. If you like inexpensive food, be glad that most farmers have caught up with the 21st century. If you persist in shooting lava at night, use the right equipment.

 

[DWThomas]

Jim Jones makes a good point. I would likely use a combination of digi and analog with the digi-guy serving as a "Polaroid" to check exposures. I'd suggest for a one time opportunity, some experimenting ahead of time to be sure the two correlate might be good. I used one of each technology for my eclipse photos last August. I was able to experiment using the full sun and filter before I left, but being able to see results on an LCD screen during the process was reassuring; plus, as in control systems, redundancy is a Good Thing(tm).

 

[Richard Man]

Just use a Nikon Speedlight, ha ha

Seriously, spot meter the lava, +2.5. Done. Bracket as needed. You may or may not get shadow details, but them's the break.

 

[Theo Sulphate]

... I used one of each technology for my eclipse photos last August. ...

I was in Rexburg, Idaho, where there was full totality for 2m 17s. No meters for me, though: I used an Exakta VX and a sunny-16 setting during totality to capture the solar corona surrounding the Moon. I made only two photos so as not to get distracted from the event.

 

[Sirius Glass]

The final results:
A week before the boat trip we were contacted by the company and told that the lava tubes had broken and the flow stopped about a mile from the ocean. They recommended that we cancel the tour. So we booked a helicopter with doors off to fly over the lava flow, caldera and a waterfall the same morning that we would have taken the boat tour. That morning it was raining. Fifteen minutes before the flight, the flight was cancelled due to safety considerations. That was our only full day on Hawaii, so we drove around the volcano that day and left early in the morning for the flight to Kauai.

Last July we also booked a doors off helicopter flight over Kauai. We took the 60 minute flight rather than the typical 50 minutes flight. We got there before dawn. The sky was clear and the weather was great. We flew on the first tour and had a wonderful and exciting time. I had started a roll of film before, but I had enough film so that I did not have to reload during the flight. Reloading would not have been practical because of the tight area and wind in the cabin.

 

[Sirius Glass]

The helicopter people said that the wide angle lenses were better for the flight and that the telephotos were not useful. I was going to use the 20mm to 35mm Nikon AF zoom lens but at the last minute opted for the 28mm to 300mm Tamron AF zoom lens. The former would have been too wide but the later was perfect. Most of the time I used it at 28mm but there were photographs that I used the longer focal length for zooming and framing.

 

[Eric Rose]

Share some pics!!