Do I get this? Flash/Ambient balancing

polyglot · Sep 4, 2012

And while it's not very APUG-y, if you have a DSLR, it makes an excellent way of previewing lighting configuration - after all, a meter can tell you ratios and the like but not exact placement of shadows & penumbra. I use an old DSLR to preview/adjust lights (like polaroids once were used) then take my proper frames on 6x7 or 4x5".

Poisson Du Jour · Sep 4, 2012

10speeduk said:
Wow! Thanks for all your answers. To flesh it out, i have a 165mm late leaf shutter lens coming and a minolta Iv flash meter too. I will run through testing with my digital before burning any porta!

The lens one of the best Pentax SMC optical performers, is a good choice to extend the flexibility of flash. Speaking of which, I bought two el cheapo thyristor flashes for $69 a pop last year, used with lumiquest diffusers, trusty L758 and auto-triggered non-corded balanced daylight fill: dead easy and I'm sure the Minolta meter will provide just the same flexibility. IMHO though diffuse ambient light is better than trying to whack things into balance in very bright sun.

Reminder re 165 LS: Don't use mirror lock-up with the 165 LS in leaf shutter mode or you'll be up for a costly repair job.

Chan Tran · Sep 4, 2012

Steve Smith said:
Then it's using the wrong units as EV (Exposure Value) has to take account of shutter speed and aperture. In fact that's all it is, the level of exposure. It does not take into account the amount of light.

However, LV (Light Value) is a measure of the light only.

At ISO 100 the figures are the same.

In the light meter's defence, it probably does state that all EV readings are for ISO 100 in the instructions but technically, using EV to represent light levels is not correct.

It's like measuring the length of a brick wall in kilogrammes. Only valid if you know the cross sectional area and the density!

Steve.

You're right about not being right. The Minolta flashmeter III when in ExIN mode. It displays play the EV value in ambient light mode and yes it's the EV value as it would change the value if you change the ISO for the same scene brightness. When the meter is in ExIN mode and it measures flash in either cord or non cord mode it display AV value (the number of stops from f/1.0). So when in this mode and the meter say EV9 it always means f/22.

Matthew Wagg · Sep 5, 2012

I'm kinda surprised no one has mentioned using a 1/4 or 1/2 CTO gel on the flash to match ambient colour temp. Obviously this only matters if you're shooting colour.
Every outdoor shot I shoot with the CTO on the strobe to avoid that flash in daylight look.

markbarendt · Sep 5, 2012

Matthew Wagg said:
I'm kinda surprised no one has mentioned using a 1/4 or 1/2 CTO gel on the flash to match ambient colour temp. Obviously this only matters if you're shooting colour.
Every outdoor shot I shoot with the CTO on the strobe to avoid that flash in daylight look.

Really good point.

Another thing I find is that many times photos are printed too light to make sense. Even when balance of lighting and color are achieved in a dark scene, many times it gets printed as if it's nearly mid-day.

Steve Smith · Sep 5, 2012

I though a flash was already matched to daylight.

Steve.

markbarendt · Sep 5, 2012

Steve Smith said:
I though a flash was already matched to daylight.

Steve.

To a point, as a baseline, yes.

Daylight's color though changes throughout the day. A sunset/late afternoon light is warmer than midday light, a flash matches midday light more that evening light. Gels can help fix that.

Mainecoonmaniac · Sep 5, 2012

Ralph is correct

RalphLambrecht said:
i usually measure the scene and pick an aperture,the flash by itself would dictate. The shutter speed is irrelevant, aperture priority in a way.

Ralph is correct. However please be aware of the maximum synch speed especially with focal plane shutters or else your shutter might cut off part of your exposure in the shot. Aesthetically, I try to keep the flash about 1 stop less than the ambient light. Your taste might be different. Do some test first. On a Vivitar 285 you can set the auto mode on a fixed f/stop then let your camera set your shutter speed. I find Vivitar 283 and 285 guide numbers are pretty accurate. You can also set it on manual mode and read the f/stop calculator.

robbalbrecht · Sep 5, 2012

I love this thread. When I shot on 1s and 0s a lot of this stuff was easy to figure out thanks the the LCD on back of the camera. Now that I'm shooting on film all the time I like having to figure a lot of this stuff out on my own and visualizing, with a little help from my meter, how my shots are going to look.

Steve Smith · Sep 5, 2012

In the olden days before auto thyristor flashes and flash meters, all that was available was the guide number.

Divide this number by the distance and you get the aperture needed (usually for ISO 100).

Despite advances in technology, dividing one number by another still works! A little bit of Google searching will probably find the guide number for your flash.

Steve.

robbalbrecht · Sep 5, 2012

Steve Smith said:
Despite advances in technology, dividing one number by another still works!

No way!!

markbarendt · Sep 5, 2012

Mainecoonmaniac said:
Originally Posted by RalphLambrecht (there was a url link here which no longer exists)
i usually measure the scene and pick an aperture,the flash by itself would dictate. The shutter speed is irrelevant, aperture priority in a way.

Click to expand...

Ralph is correct. However please be aware of the maximum synch speed especially with focal plane shutters or else your shutter might cut off part of your exposure in the shot. Aesthetically, I try to keep the flash about 1 stop less than the ambient light. Your taste might be different. Do some test first. On a Vivitar 285 you can set the auto mode on a fixed f/stop then let your camera set your shutter speed. I find Vivitar 283 and 285 guide numbers are pretty accurate. You can also set it on manual mode and read the f/stop calculator.

Ralph's idea works, but as you say there are real limits and for me it starts in the wrong place creatively.

Personally the flash is the last thing that I let dictate to me.

Aperture is typically my first choice, to get DOF right for the subject or style of shot.

Time limits are next in line, subject matter again dictates here but also sync speed. Typically for me it relates to age and activity, 1/30th may work for adults around a campfire with camera support, for youngun's or moving subjects or hand held I want to be up close to sync speed.

Aperture and time and background lighting (that I can't change) then dictates my EI.

Finally after all that is addressed then I start setting up the strobe for the subject. The reason I do strobes last is that they are adjustable and all the other choices are taken in my world.

With practice it can be easy and fast because we all find norms that work for us. Personally if I'm outside and there's a strobe attached to my camera the aperture is f/2.8, the shutter is between 60 and 125, the camera is on a monopod, the EI is judged by the situation, and my Nikon speedlites are on "A" or matrix TTL with no compensation.

Mainecoonmaniac · Sep 5, 2012

My Canon and flash system is so old there's no TTL. I've had to use the guide number system or the auto mode. I'm sure TTL are way more accurate that the system I use. Don't they shut the flash off as soon as there's enough light from the flash hitting the film? The auto sensors on the my Vivitar 285 shuts off the flash when enough light bounce off the subject.

markbarendt · Sep 5, 2012

The auto shut off is actually true for both auto and TTL. Power on flash units is adjusted by duration, luminance is typically fixed.

TTL, even balanced matrix TTL, isn't necessarily better, it's just a tool.

I use auto a lot especially where I can bounce the light. It lets me use slower films with faster shutter speeds, keeps me in the 400 EI range instead of 3200.

removed account4 · Sep 5, 2012

i try to keep it simple
i measure and pick the aperture and speed for the ambient light and adjust the fstop or
shutter speed to under expose what the flash says. i have a electric eye for my lumedyne 244
and i can tweek the light from 2 ws to 200, so it makes it ez to tweek just a little bit...

RalphLambrecht · Sep 11, 2012

Steve Smith said:
I though a flash was already matched to daylight.

Steve.

i think, er are talking an\bout intensiy,not color

Steve Smith · Sep 11, 2012

RalphLambrecht said:
i think, er are talking an\bout intensiy,not color

We were talking about colour because colour gels were mentioned.

Steve.

RalphLambrecht · Sep 11, 2012

sorry, i must have misunderstood, i thought the sue was lght intensity balancing between flash and am bient, which is tricky enough.

ric_kb · Sep 12, 2012

what is the ratio of fill you want?

RalphLambrecht · Sep 22, 2012

sounds very logical and workable to me!

Do I get this? Flash/Ambient balancing

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