Intro to daylight flash photography

[Shane Knight]

I forgot to add.
Again, for outdoor flash photography. You can "fudge" the max sync speed.
If the subject is in center or left of center you can set your shutter faster by one or two stops. The film plane is still catching the flash (hopefully the subject) but not quick enough to pass through the whole frame (where flash is not needed). I really can't explain this well. Just experiment and you'll see.

Ps. The above is true for Nikon F4 and I might have right vs left mixed up. Its been a long time.

 

[film4Me]

Spare a thought for me taking flash shots with ancient 3A Kodak folders set on "T" and a tiny aperture opening. The flash is a Metz 40CT4 operated manually by pressing the rear red button, relying on the thyristor to do the rest. Quite spectacular, it transforms these very early Kodaks into "Hasselblad" quality.

 

[hwy17]

I forgot to add.
Again, for outdoor flash photography. You can "fudge" the max sync speed.
If the subject is in center or left of center you can set your shutter faster by one or two stops. The film plane is still catching the flash (hopefully the subject) but not quick enough to pass through the whole frame (where flash is not needed). I really can't explain this well. Just experiment and you'll see.

Ps. The above is true for Nikon F4 and I might have right vs left mixed up. Its been a long time.

That's an interesting concept thank you. That would probably work for me since I'm usually trying to light up a face in the middle of the frame. Probably can't use TTL then? Maybe when I learn more.

 

[koraks]

I've done what you're trying to do a lot, with Canon eTTL flashes (420, 580). Dial flash exposure compensation to e.g. -1.5 stops, keep subject exposure at normal or slightly under (e.g. -2/3).

High speed sync is kind of silly; it's a machine-gun burst of flashes that fire rapidly in the approximate timeframe the shutter opens. The idea is that the shutter will capture at least some of the flashes of this 'pulse train'. The logical consequence is that you lose a lot of flash power (and eat a lot of batteries) since many of the actual flash pulses never end up in the actual exposure. Hence the 'downrating' of the guide number as mentioned before. I always considered it a last resort and frankly virtually never used it, but if you want to shoot at fast shutter speeds (brightly lit scenes with large aperture) on a TTL system there's no way around it - and it does work.

The TLDR is that you can use TTL exactly as its intended to: by commanding the exposure compensation for both the Flash and available light exposures and let the system do the rest. It really works and you can get by without understanding guide number math as it doesn't even come into the story.

 

[MattKing]

It really works and you can get by without understanding guide number math as it doesn't even come into the story.

I'll differ a little bit with respect to this.
If you understand the guide number approach first, you are more likely to be able to get things into the ballpark first, and then let the auto systems refine everything.
Basically, you avoid the disappointment of trying to accomplish things in circumstances and with equipment unsuitable for the task.
You know, the "backlit using fill flash team photo of the football team in the sun filled stadium, using fast film and a tiny TTl flash" challenge.

 

[hwy17]

Thanks @koraks

I completed a new development last night including tests of Nikon F80 Matrix-TTL at 1/125s as well as Canon Rebel 2000 high speed.

I've clearly missed a key interface for the Canon highspeed. On a close indoor subject at night time I bracketed all the way up and down from 1/250 to 1/2000 and half or more of them came out critically underexposed. I must have been unaware of something in the viewfinder that warns about this exposure problem, and that answers one of my questions; When choosing a speed in high speed flash mode the working speeds will still be variably limited by the available light.

My F80's are my favorite, so I'll continue working with the 1/125 and if I run into sharpness difficulty with it then I'll have to figure out how to get the F4 working automatically at 1/250.

 

[BrianShaw]

Spare a thought for me taking flash shots with ancient 3A Kodak folders set on "T" and a tiny aperture opening. The flash is a Metz 40CT4 operated manually by pressing the rear red button, relying on the thyristor to do the rest. Quite spectacular, it transforms these very early Kodaks into "Hasselblad" quality.

No kidding; Is that so? Depending on which lens it has it certainly is possible to get good images. Mine has a B&L RR and I get good images. But "Hasselblad quality"; I think not so much.

 

[Dan Fromm]

No kidding; Is that so? Depending on which lens it has it certainly is possible to get good images. Mine has a B&L RR and I get good images. But "Hasselblad quality"; I think not so much.

Brian, some #3A FPKs have f/6.3 Tessars in Compound shutters. I've shot some of these lenses on 2x3. They're better than good enough.

 

[ic-racer]

I have been doing daylight flash for years, my take home message is that it involves a lot of trial and error.

Sometimes a simple non-ttl auto set to 1/2 or 1/4 of the full exposure works as well as a more complicated ttl matrix fill flash.

 

[cowanw]

Topcon made 35mm cameras with leaf shutters.

 

[MattKing]

As did Kodak.

 

[koraks]

When choosing a speed in high speed flash mode the working speeds will still be variably limited by the available light.

Not sure what you mean by this exactly, but there are two things going on:
1: shutter speed along with aperture dictates the amount of available light being recorded. Just like always.
2: if the available light exposure is insufficient, Flash can fill in, but that's also limited to the power of the flash. If you use very short exposure times with HSS, the amount of flash exposure is moreover limited to the number of flash pulses captured during the brief exposure and the power per pulse. These HSS pulses are much weaker than the single pop you get in normal sync mode. A shorter shutter speed allows the camera to capture fewer of these weaker pulses, so the effective flash exposure available in HSS drops as shutter speed goes up.

@MattKing sorry, but I disagree. Understanding guide number math really doesn't help setting a camera in eTTL or iTTL mode. It can even confuse the user further. In general background knowledge is of course favorable, but in this case it's really of exceedingly limited practical utility.

 

[MattKing]

@MattKing sorry, but I disagree. Understanding guide number math really doesn't help setting a camera in eTTL or iTTL mode. It can even confuse the user further. In general background knowledge is of course favorable, but in this case it's really of exceedingly limited practical utility.

Perhaps not the math per se, but if you understand the manual capabilities of your flash, that will help you understand over what range of situations - mainly working distances, ambient light levels, film speeds and lens apertures - for which the TTl auto functions will make appropriate adjustments.
Even the best circuits can't make a 2 AA battery flash do the same job that a high voltage battery pack powered "potato masher" style can do in a lot of circumstances.

 

[IpseLux]

Not sure what you mean by this exactly, but there are two things going on:
1: shutter speed along with aperture dictates the amount of available light being recorded. Just like always.
2: if the available light exposure is insufficient, Flash can fill in, but that's also limited to the power of the flash. If you use very short exposure times with HSS, the amount of flash exposure is moreover limited to the number of flash pulses captured during the brief exposure and the power per pulse. These HSS pulses are much weaker than the single pop you get in normal sync mode. A shorter shutter speed allows the camera to capture fewer of these weaker pulses, so the effective flash exposure available in HSS drops as shutter speed goes up.

@MattKing sorry, but I disagree. Understanding guide number math really doesn't help setting a camera in eTTL or iTTL mode. It can even confuse the user further. In general background knowledge is of course favorable, but in this case it's really of exceedingly limited practical utility.

Not necessarily. Flash output bypasses shutter speed, and is only dependent on aperture. That’s a great secret and advantage of knowing and using the guide number of flash. And the math is so simple, basic division. Guide numbers in units of meters are handy in that everyone understand an arm’s length….
Flash also freezes the image.
Now, don’t take me wrong, I love my Nikon Speedlights.
But the old Vivitar 285HV in auto is pretty spectacular too.
Note, I use the word “bypasses” rather loosely. I’m not speaking univocally here.
But any flash sync speed and lower that doesn’t overexpose the image will work with guide number and aperture on manual flash.
And here’s the extra bit of wisdom, want to set multiple flashes and light up the subject in various f stops of light? Use the aperture numbers, 22,16,11,… as distances of your flash sources.
It’s all there. Old school photographers developed a tremendously useful system to understand, master and control light.
I think it is brilliant.

 

[Paul Howell]

Topcon made 35mm cameras with leaf shutters.

Kodak, Topcon, Kowa and Zeiss all made 35mm cameras with leaf shutters, I have a Topcon and Kowa along with a Kodak Retina IIIC big. I have only shot a few rolls with flash, bulbs and electronic. With M press bulbs with very high guide number reach is very far, wide open, but possible to shoot at F 11 or 16 at 10 feet. Topcon had shutter speed pefered auot exposure with lens that ranged from 28 to 200, somewhat slow and heavy. For the most part Kowa made fixed lens SLR, only the model had interchanable lens bodies. Due to complexity of the shutters and light baffel to block light when shutter is closed very hard to get serviced.

 

[koraks]

Flash output bypasses shutter speed, and is only dependent on aperture

Please note I'm referring to high-speed sync (HSS) in a TTL system.

 

[wiltw]

Please note I'm referring to high-speed sync (HSS) in a TTL system.

Nevertheless the use of high FP speed shutter flash does affect both film systems and digital systems in the same way.

With the rapid-pulse approximation of 'constant' light output, as the focal plane curtain slit gets narrower as the shutter speed gets faster there is a reduction of light reaching the film surface. So HSS light distance is effectively reduced by focal plane shutter speed increases.

Guide Number arithmetic understanding does help with anticipating range decrease with HSS (vs. convention full power output), so you know in advance what distance to not exceed. If you know that flash output at a given aperture decreases (typically) by -2EV, use the max distance at full power as if it were an aperture value, and decrease by 2 EV...for example, if your max flash distance would be 10' at full power, ... Using Guide Number arithmetic, GN 110 = 10' * f/11, and cutting GN/2 = GN 55 =5.5' / f/11
...alternatively, convert mas normal distance to aperture (e.g. f/10), and using HSS you will be limited to a shorter range whose numerical value is like 2EV larger aperture (e.g. f/5.5).

 

[koraks]

Or press a button and the camera tells you within a second whether your subject will be properly exposed.

One can write out a message with pen and paper before typing an email. There's can be an advantage to it. But it's not really necessary.

 

[wiltw]

Or press a button and the camera tells you within a second whether your subject will be properly exposed.

One can write out a message with pen and paper before typing an email. There's can be an advantage to it. But it's not really necessary.

One can PLAN ahead via the GN process understanding, so you can figure out an alternative plan, not merely need to immediately REACT to a situation discovered with the button press.

 

[eli griggs]

It depends. Back when I shot flowers, insects and such in broad daylight with ISO 25 Kodachrome and low power flashes at short flash-to-subject distances. I got consistent good exposure.

Fill flash? More powerful flashes such as Vivitar 283s and auto-exposure.

These days I use relatively inexpensive (used prices) Nikon i-TTL flashes with a D810. 1/320 shutter speed, ISO dialed all the way down to minimize exposure from ambient light.

Until the OP gives us more specifics we're just guessing about what might be right.

I carry some lengths, short, less than two feet of fiber optic, of 3.5 mm, bought off Amazon , for running between the Vivitar/Sunpac flash sensor to the face of the flash, cut to length for very controlled flash lighting.

One of the first things I want to print on my 3D printer is a detachable sensor fitting for holding the line in place on the 283 flash unit for extreme close up shots.

The idea is the flash fires, and light enters the line at the flash face, which travels down to the sensor, which cuts off the pulse and light at the correct intensity, for the closeup photo.

Many years ago National Geographic photographers used this method to make a great cover photo of the tongue of a lizard taking an flying insect mid flight, the background of the lizard a beautiful blacked out scene.