What f-stop should I set my flash?
Nov 12, 2018 21:30:31 #
kenArchi
Loc: Seal Beach, CA
An accurate and quick reading will be in f-stop versus using some sort of GN calculations?
Nov 12, 2018 21:38:17 #
kenArchi wrote:
An accurate and quick reading will be in f-stop versus using some sort of GN calculations?
GN number calculations tend to have a lot of error. The first is that virtually all flash manufacturers inflate their GN rating so you need to test and determine the true GN. Second the GN only works for direct flash. Using the flash meter is generally easy and very accurate. It's the best way if you use film. However, nowaday I shoot digital I generally don't use the flash meter although I have 2 excellent flash meters. I simply guess at the setting, take a shot, do a review and make an adjustment based on the test shot. I tend to get it right with the first guess because I have a feel for my flashes.
Nov 12, 2018 22:02:25 #
Out of the box idea! Sounds to me that the OP may have an older system and his question may pertain toe AUTO FLASH usage as opposed to TTL, manual or direct flash dedication. In that system the flash operates independently of the camera on its own thyristor circuit. There are settings on the flash for ISO and a pre-set f/stop. The camera is then manually set for that aperture. Ostensibly, if everything is in order, a photelectric cell on the front of the flash unit will instantaneously read the light reflected from the subject and increase or squelch the flash power output to accommodate the pre-set aperture. It works like TTL- without the lens- there is no integrated circuitry with that of the camera except for basic synchronization.
I have a few older flash units that work that way and they are surprisingly accurate if used correctly within their limitations.
If this is the case, the answer to the question is to set the flash and the camera to the same f/stop. Make some tests and make any necessary compensations in settings. Make certain the the shutter speed is set to the proper synchronization limits.
I have a few older flash units that work that way and they are surprisingly accurate if used correctly within their limitations.
If this is the case, the answer to the question is to set the flash and the camera to the same f/stop. Make some tests and make any necessary compensations in settings. Make certain the the shutter speed is set to the proper synchronization limits.
Nov 12, 2018 22:18:58 #
alx
Loc: NJ
Download the manual for the make/model of the flash and read it.
Your questions don't provide any of us with enough information to even make an adequate guess.
The vast majority of us here (myself included) are psychotic, not psychic.
Your questions don't provide any of us with enough information to even make an adequate guess.
The vast majority of us here (myself included) are psychotic, not psychic.
Nov 12, 2018 22:21:10 #
I've learned through experimenting with flash that the more open your aperture the more light it lets in. So if I'm shooting at f/2.8 then I use less power in my flash output. If one chooses f/11 then more power is needed. I don't get in to the technical stuff of GN numbers. How much power you want to set your flash on depends somewhat on your artistic preferences too. Also, a small flash will require a higher power setting than a big strobe light.
Nov 12, 2018 23:11:37 #
E.L.. Shapiro wrote:
Out of the box idea! Sounds to me that the OP may... (show quote)
I thought so too but the OP refused to tell me which make and model it is. He said it's all manual what the different does that make about make and model. I wanted to help but the OP really made it difficult.
Nov 13, 2018 01:05:27 #
BebuLamar wrote:
My 600 EX RT's are certainly compatible with my cameras and I do always set the f/stop on them!What flash are you talking about? Make and model please. A modern flash that is compatible to your camera you don't have to set any f/stop on the flash.
Nov 13, 2018 01:28:36 #
I have to retract my previous post. I read the question , started to answer it and was called back to work. So...I finished the post without reading all the back and forth in the thread. Seems he was inquiring about strictly manual operation of his flash gear so my remarks about auto flash etc were moot.
The OP has been on the forum for a number of years and has posted a good number of images which leads me to believe he is not a novice in that his images show a good command of lighting- at least natural light and his compositions are far from amateurish. He purports to have good equipmet and evidently has a good command of its usage.
Perhaps he is new to flash usage. Going by back and forth comments, I wonder if his questions are rhetorical. If the questions are indeed sincere, I offer the following.
All electronic flash equipment does operate on the same basic principles, however there are many differences in power output, prescribed usages, applications and methods of control of light output and exposure.Besides popular speedlights and mono-lights there are many othere configurations, makes, models and types.
Like any othere light source, especially artificial types, the important theory to study is the INVERSE SQUARE LAW which is indicative of how light diminishes with distance from the subject. Other practical subjects to study are the use of guide numbers in calculating exposure. These are the basic parameters of exposure determination with flash equipment other that the use of a flash meter or the employment of an automatic or TTL camera system.
Flash systems are rated in a number of differet values. Watt.Seconds is a electrical value that is based on voltage and capacitance that indicated the power applied to the flash tube. ECPS or BCPS is a value is more of a light efficiency or effective value based on output, reflector design and coverage. A GUIDE number is usually assigned to any giveen flash unit at a given ISO by the manufacturer. To determine the f/stop or aperture- you divide the GN by the distance in feet between the flash unit and the subject. For example, if the GN is 100, at a distance of 10 feet you aperture is f/10- set the camera between f/8 and f/11. Most experienced flash users use the published GN as a starting point for testing and determine there own customized GN for there specific working conditions. Experienced MANUAL users know how to estimate dissonances and set the apertures accordingly. More precise exposure determination can be achieved with a flash meter. Studio shooters oftentimes have standard pre-set operating distances and learn to instinctively set ther exposures governed by experience.
On flash equipmet with adjustable outputs (1/2, 1/4, 1/8/power etc) the output changes and the GN also changes accordingly. The basic GNs are for direct flash usage with the reflector supplied with the unit. When ligh modifiers or bounce techniques are employed, all bet are off and exposure compensations must be made.
A modern flash meter, when properly set with the ISO speed in use and aimed properly in reflected or incidents light modes supply a digital readout in f/stops.
All of theses basic specification that apply to various flash gear are all instrumental in exposure determination. That is why folks here are asking for makes, models and specifics.
Flash techniques can be very simple and straightforward or very sophisticated. There are meths of combing flash with all manner of neutral and existing light, there are multiple and studio and studio-like flash systems and techniqes and like any othere ligh source there are infinite studies of aesthetics.
Other flash facts to investigate: Flash duration, shutter speed synchronization limitations, actio freezing abilities, color temperature (electronic flash approximates daylight), white balance settings and trigger voltage safety where older units are connected to modern digital cameras.
I hope some of this helps!
The OP has been on the forum for a number of years and has posted a good number of images which leads me to believe he is not a novice in that his images show a good command of lighting- at least natural light and his compositions are far from amateurish. He purports to have good equipmet and evidently has a good command of its usage.
Perhaps he is new to flash usage. Going by back and forth comments, I wonder if his questions are rhetorical. If the questions are indeed sincere, I offer the following.
All electronic flash equipment does operate on the same basic principles, however there are many differences in power output, prescribed usages, applications and methods of control of light output and exposure.Besides popular speedlights and mono-lights there are many othere configurations, makes, models and types.
Like any othere light source, especially artificial types, the important theory to study is the INVERSE SQUARE LAW which is indicative of how light diminishes with distance from the subject. Other practical subjects to study are the use of guide numbers in calculating exposure. These are the basic parameters of exposure determination with flash equipment other that the use of a flash meter or the employment of an automatic or TTL camera system.
Flash systems are rated in a number of differet values. Watt.Seconds is a electrical value that is based on voltage and capacitance that indicated the power applied to the flash tube. ECPS or BCPS is a value is more of a light efficiency or effective value based on output, reflector design and coverage. A GUIDE number is usually assigned to any giveen flash unit at a given ISO by the manufacturer. To determine the f/stop or aperture- you divide the GN by the distance in feet between the flash unit and the subject. For example, if the GN is 100, at a distance of 10 feet you aperture is f/10- set the camera between f/8 and f/11. Most experienced flash users use the published GN as a starting point for testing and determine there own customized GN for there specific working conditions. Experienced MANUAL users know how to estimate dissonances and set the apertures accordingly. More precise exposure determination can be achieved with a flash meter. Studio shooters oftentimes have standard pre-set operating distances and learn to instinctively set ther exposures governed by experience.
On flash equipmet with adjustable outputs (1/2, 1/4, 1/8/power etc) the output changes and the GN also changes accordingly. The basic GNs are for direct flash usage with the reflector supplied with the unit. When ligh modifiers or bounce techniques are employed, all bet are off and exposure compensations must be made.
A modern flash meter, when properly set with the ISO speed in use and aimed properly in reflected or incidents light modes supply a digital readout in f/stops.
All of theses basic specification that apply to various flash gear are all instrumental in exposure determination. That is why folks here are asking for makes, models and specifics.
Flash techniques can be very simple and straightforward or very sophisticated. There are meths of combing flash with all manner of neutral and existing light, there are multiple and studio and studio-like flash systems and techniqes and like any othere ligh source there are infinite studies of aesthetics.
Other flash facts to investigate: Flash duration, shutter speed synchronization limitations, actio freezing abilities, color temperature (electronic flash approximates daylight), white balance settings and trigger voltage safety where older units are connected to modern digital cameras.
I hope some of this helps!
Nov 13, 2018 05:50:42 #
billnikon
Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont
kenArchi wrote:
When I set my camera at f-5.6, 1/60 second to take a picture of my subject, what f-stop should I set my flash?
I am confused. You said you set your f stop and 5.6 and you want to know what f stop to use on the flash. Usually on Nikon the flash will show the same f stop as the camera.
Nov 13, 2018 06:29:15 #
kenArchi wrote:
Does it matter if I am using a studio or on camera flash?
They do put out an instant burst of light right?
And will a flash meter read the f-stop output?
And can you not adjust the flash from full power to 1/128th power?
They do put out an instant burst of light right?
And will a flash meter read the f-stop output?
And can you not adjust the flash from full power to 1/128th power?
A flash meter will give you f-stop readings. This is the screen of my Sekonic L-478DR meter. It can also display the percentage of flash as part of the overall exposure. You can also turn on additional information such as EV (exposure value).
(Download)
(Download)
(Download)
Can display flash output as a percentage of the total exposure
(Download)
Nov 13, 2018 07:47:59 #
Well done!
How about bouncing your flash? Shoot, Chimp, Adjust, Shoot, Chimp, Adjust
How about bouncing your flash? Shoot, Chimp, Adjust, Shoot, Chimp, Adjust
CO wrote:
A flash meter will give you f-stop readings. This is the screen of my Sekonic L-478DR meter. It can also display the percentage of flash as part of the overall exposure. You can also turn on additional information such as EV (exposure value).
Nov 13, 2018 08:24:41 #
BebuLamar wrote:
I thought so too but the OP refused to tell me which make and model it is. He said it's all manual what the different does that make about make and model. I wanted to help but the OP really made it difficult.
(Hope it's not an old one with a 250v+ trigger.)
Nov 13, 2018 08:42:42 #
It also depends on the effect you want. I leave my built-in flash on minus 1, because I use it more as a fill, and set the shutter speed of the camera to expose the background so it is not all black behind my subject. If you are talking about an off camera flash, and don't care about the background, just set it to the ISO of the camera, and 5.6, or 1/2, 1/4, 1/8 power. Either way, take a shot or two, and check your "photo review" to see if the subject is lit the way you want.
Nov 13, 2018 09:03:38 #
PixelStan77 wrote:
Make sure the flash you are using is designed for your camera or you could ruin the electronics in the camera.
How so? What would cause this to happen? Trying to make sure I understand why - so I don't mess up.
Nov 13, 2018 09:05:04 #
Responders are asking questions to determine what type of flash you have in order to give you a correct answer. Older units used a "guide number" that corresponded to the power of that particular flash unit and either on the unit itself or in the manual was a scale in feet or meters that for a given F-stop provided the flash to subject distance for proper exposure. Newer units called "thyristor" controlled units would "read" the F-stop and ISO you have set and automatically adjust the flash duration to achieve proper exposure. Perhaps next time you will not be so rude to those trying to help you.
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