TTL Flash and Macrophotography

[geri_brandimarte2]

I am in the process of deciding on a MF camera. One of the things I would like

to do is some macrophotography. Having no experience with this type of

photography I am curious how important TTL flash will be in this effort. Also,

will leaf shutter lenses be more beneficial for this type of photography (for the

added flash sync speed).

 

Thank you, Geri Brandimarte

[dan_fromm2]

TTL flash for close-up is somewhat problematic because of varying reflectivity of the subjects. Think of the difference between reflected and incident metering with ambient light.

 

Leaf shutters help a lot because they offer much higher sync speed than focal plan shutters.

 

Example. By the sunny 16 rule, with ISO 100 film the appropriate exposure is 1/100 @ f/16. @ 1:1, that translates to 1/25 @ f/16. If ambient is much less than three stops down from the flash, you're in trouble. So, if your focal plane shutter syncs flash @ 1/30, you'll need to be @ f/45 to eliminate ghosting from flash. If you're not too fussy, f/32. Not a good aperture to use at 1:1. At 1/60, you're still in trouble.

 

There are three cures. Leaf shutter that syncs faster; neutral density filter in front of the lens and turn the flash up; slower film. The ND approach will work, but is obnoxious. Velvia or TP and pray, may work for those who can stand 'em, not an option for those who don't.

 

NOW do you understand why those of us who shot KM 135 closeup out of doors with flash were so unhappy when it was discontinued? And many of us had flash sync @ 1/250.

[richard_cochran]

The situation where a leaf shutter's high sync speed is useful

is when you have lots of ambient light, and you want to

shoot relatively wide open, and balance ambient and flash.

That's not likely to be an issue with macro photography,

because you're usually stopped way down, and your flash

can be placed close enough to the subject that it

easily overpowers ambient light.

<p>

TTL metering is useful for macrophotography, probably even

more so than non-macro photography, because it saves

having to compensate for bellows extension factor. But compensating

for bellows factor is not extraordinarily difficult (open up

one stop at 1:2, two stops at 1:1). The best lit macro photos,

like non-macro photos, come by getting the flash off the camera's

hot shoe, and bouncing or diffusing the light, so be sure your

flash setup allows this. It can be more expensive to take TTL

flashes off the hot shoe than non-TTL flashes.

<p>

Personally, I find it's easy

and very reliable to use an ordinary manually adjustable flash

on an ordinary PC sync cord, combined with an incident flash

meter and manual camera settings. 12" white reflector or

umbrella to bounce the light off can be very useful, or

a small softbox can also be used.

[dick roadnight cotswolds]

Richard:

 

Yes, TTL helps a great deal, as do leaf shutters.

 

I use 2 Metz 70s, one close to the camera as a fill in, and the main light away from the camera, in TTL wireless slave mode.

 

In the confines of a macro set-up reflectors work better than in a larger studio.

 

This works, even with difficult subjects like diamonds.

 

Ideal for butterflies.

[dan_fromm1]

Richard, after experimentation and calculation I've decided that f/16 is about as is safe to stop down when working near 1:1, so ambient light isn't, at least for me, of more theoretical than practical concern. And this after thinking hard about and fiddling with the tradeoff between sharpness in the plane of best focus and depth of field. I'm using reasonably good lenses (105/2.8 MF MicroNikkor on 135; 100/6.3 Neupolar and 100/6.3 Luminar on 2.25 x 3.25, Reichert beats Zeiss), so I don't think that they're an issue.

 

Much below 1:1, stopping down is of course still an option. Above 3:1, wide open is best with the lenses I've tried.

 

Cheers,

 

Dan