Using a strobe's modeling light, where to aim?

[ccredifo]

If an object appears 3 feet away, it's really 4 feet away. If you're using a strobe that has a modeling light do you aim the light at the subject or do you aim past the subject?

I'm guessing that you need to point past the object but thought I'd check.

 

[oly5050user]

If an object appears 3 feet away, it's really 4 feet away. If you're using a strobe that has a modeling light do you aim the light at the subject or do you aim past the subject?

I'm guessing that you need to point past the object but thought I'd check.

if the strobe has a modeling light then whatever the modeling light illuminates is where the stobe is going to light up..

 

[gert7to3]

This is a potential problem with a modeling light in a strobe. You have the strobe pointed full on your subject, because that's where the modeling light directs you. Then there is the risk of putting too much light into the water column between your lens and your subject. This increases backscatter. You may need to shift your modeling light a little past your subject.

 

[oly5050user]

This is a potential problem with a modeling light in a strobe. You have the strobe pointed full on your subject, because that's where the modeling light directs you. Then there is the risk of putting too much light into the water column between your lens and your subject. This increases backscatter. You may need to shift your modeling light a little past your subject.

if the model light is built into the strobe then you are good to go as I had earlier stated.The model light is nowhere near as bright as the strobe flash and will not add too much light on to subject. The model light itself would have to be stronger/brighter than the strobe to make any difference and then the strobe itself would be useless.It will not contribute to backscatter anymore than what the strobe flash itself would do.Too much light does not contribute to backscatter,either its there or not,only angle of positioning and amount of particulate matter in water affects how much backscatter shows on image.

 

[cdiver2]

if the model light is built into the strobe then you are good to go as I had earlier stated.The model light is nowhere near as bright as the strobe flash and will not add too much light on to subject. The model light itself would have to be stronger/brighter than the strobe to make any difference and then the strobe itself would be useless.It will not contribute to backscatter anymore than what the strobe flash itself would do.Too much light does not contribute to backscatter,either its there or not,only angle of positioning and amount of particulate matter in water affects how much backscatter shows on image.

The point Gert is trying to get across is, You do not want to aim your strobes directly at the subject you may get back scatter or a hot spot. Better to get the side of the beam for a softer more even illumination. Better still 2 strobes one aimed just to the left of the subject the other just to the right and the side of each beam cross on the the subject, with the focus light independent of the strobes.

focus light on a single strobe aim just behind and to one side.
http://www.boydski.com/diving/uwphoto.htm

 

[MauiScubaSteve]

I would say it depends on the camera/housing/strobe system. Does the camera require the modeling light in order to assist with auto focus? With my 5050/PT-015, the camera uses a focus beam and does not need a modeling light to assist with focus. Other camera/housing combinations do not have this self focus ability, or it is not as good. With my SS200, a coffee can lid diffuser works well with regard to hot spot issues, and on a night dive the modeling light is my primary dive light yet the strobe is all that is seen in the image.

With respect to photographic composition, remember the rule of thirds. If your subject is positioned according to this rule, aiming an integrated modeling light at the subject may result in uneven lighting of the whole image.

In this digital age, review is your friend! With the 5050, raw record time is significant. I use this time to look at the image as it is recorded. The progress bar hides the center of the image, but even just seeing the periphery I have a good idea of how well I aimed the strobe, as well as exposure +/-. With subjects that stick around, I can spend time to achieve better aim/exposure. With more fleeting subjects, my practice with the stationary subjects makes my aim/exposure better when it needs to be.

Other cameras, housings, strobes and various combinations have different best practices. Better to ask with regard to the equipment you intend to use.

 

[MauiScubaSteve]

The point Gert is trying to get across is, You do not want to aim your strobes directly at the subject you may get back scatter or a hot spot. Better to get the side of the beam for a softer more even illumination. Better still 2 strobes one aimed just to the left of the subject the other just to the right and the side of each beam cross on the the subject, with the focus light independent of the strobes.

focus light on a single strobe aim just behind and to one side.
Underwater Photography

The OP seems to be with regard to a strobe. This answer/link seems to be with regard to dual strobes. I shoot a lot with an INON WAL, using a single strobe with 100 deg coverage. To cover the entire image, even with a diffuser, the strobe needs to be pointed at the center of the image.

As the subject distance changes, the aiming of the strobe needs to change. One theory is that light falls underwater, so as distance to subject increases, aiming a little above center looks like the strobe burst is centered.

Backscatter is greater as the angle of strobe is closer to parallel with the sensor view. Using the internal flash will result in the most BS, since it is closest to parallel. Holding your strobe as close to the lens as possible will give the most BS with a strobe. The farther away from the camera you hold the strobe, the less BS you will see. Using the edge of a single strobe on the subject will result in one side of the image being much darker than the other. The amount of BS between the subject and lens will be the same, but like most of the entire image it will not be as bright.

Using a single strobe is the most common form of underwater strobe photography. Dual strobe systems are for a small minority of divers, for various reasons. Many of the most famous underwater images in the world were taken with single strobes. Quite a few of the most famous underwater images in the world were taken with internal flash. Some of the most famous underwater images in the world were taken with no strobe/flash (ambient).

In general, I try to aim the strobe at the center of the image. If backscatter is an issue I put as much distance between the strobe and lens as possible. If there is a lot of particulate matter in the water, some backscatter in the image gives the image a more realistic feel. In many eyes, an image with absolutely no BS has a sanitized feel and lacks depth. The same is often said about the lack of shadows with dual strobes. Art can be accomplished with a pinhole box, just ask Ansel Adams fans.

 

[giriwil]

if the strobe has a modeling light then whatever the modeling light illuminates is where the stobe is going to light up..

you're right. it the same with the surface photography. Modelling light can help you to control area/subject that should be iluminated... and control the shadow too

 

[ScubaSteve]

Without the use of the modelling light, your camera will be unable to focus (no focus light was mentioned so it is assumed not to exist) on anything and your picture is not likely to be "memorable". Aim the modelling light at your subject. Make sure the angle of the light is such that BS will not be an issue. Because the modelling light is pointed at the subject, your strobe will illuminate it.

 

[MauiScubaSteve]

Without the use of the modelling light, your camera will be unable to focus (no focus light was mentioned so it is assumed not to exist)

I would reiterate my opinion that depending on the camera/housing some combinations focus well without the use of a focus light.

My SS200 has a modeling light that I use on night dives. That light has nothing to do with the 5050/PT-015's focus, but it allows me to aim the strobe; hence the use of the term modeling light.

Some cameras need the light to assist with focus; hence the use of the term focus light. The OP only uses the term modeling light so why would I assume the camera needs a focus light?