I know my M6TTL's principal virtue is available light photography, but there are times when I need flash -- for fill-in or more. Rather than shell out the $250 for the Leica SF20, I bought the Olympus S20 for $50 at the suggestion of the B&H counterman. It's a nice flash and works well enough in dim or dark locations. Trouble is, when I use it for fill-in, my shots are consistently overexposed. What's the trick to using a non-TTL flash for fill-in. I welcome all advice.

-- Steve Reston (SteveR4@aol.com), November 23, 2001

Answers

I've not used the Olympus flash, but the first thing you want check with any auto flash is that the film speed setting on the flash matches the film you are using. Then one technique you can try is to use an aperture on your lens that is 1/2 to 1 stop slower than the auto aperture you select on the flash. The resulting bit of underexposure by the flash often results in a more natural looking fill.

-- Jack Flesher (jbflesher@msn.com), November 24, 2001.

The M6 TTL uses the SCA 3000 TTL circuitry that is built into the SF20, and available for various other flash units. There are, however, multiple SCA systems, and not all are compatible. I'm not familiar with the Olympus S20 either, but at that price, I doubt that it is SCA 3000 compatible. You will likely need to use it in either manual mode or using the on-flash auto-exposure sensor. If it has exposure compensation capability, experiment with that, ranging from 1/2-stop below your ambient light exposure to as much as 2 stops below, depending on the lighting situation. If it doesn't have exposure compensation, you may be able to accomplish the same thing by adjusting the ISO setting upward.

I'd be cautious about trying to use the flash in TTL mode (assuming it has that mode). Different units apply different voltages to the TTL circuit through the hot shoe, and you could actually damage the TTL circuitry in the M6.

-- Ralph Barker (rbarker@pacbell.net), November 24, 2001.

Jack, by using a slower aperture on the lens don't you risk losing the background by underexposure?

Bert

-- Bert Keuken (bkkn@wanadoo.nl), November 24, 2001.

Bert:

Sorry for the confusion -- I should have clarified a bit further. To me the term "fill falsh" implies that you have first set your camera to a proper exposure for the abient light in the scene, then set the flash up to "fill" in the shadows. So, I should have more accurately stated that after you have set your camera exposure, you should select an aperture on the flash that is 1/2 to 1 stop larger than the one on the camera. This will generate a "fill" that is 1/2 to 1 stop darker than ambient, and hence "fills" shadows nicely without eliminating them.

Cheers,

-- Jack Flesher (jbflesher@msn.com), November 24, 2001.

The S20 (my favorite flash for the M6!) has a dial on the back with positions for AUTO-1 and AUTO-2, and a chart that tells you what aperture to use with each AUTO setting for ISO 100, 200 and 400 film. For daylight fill, you need to refer to the chart for the next- faster film speed (ie, ISO 200 if you're loaded with ISO 100 film)and set that recommended aperture on the lens. Then, you need to adjust the shutter to balance the LED's for the correct daylight exposure and hope that doesn't take you faster than the 1/50 sync speed. With the 2 AUTO settings, you'll get 2 possible aperture choices, 2 stops apart. Good luck!

-- Jay (infinitydt@aol.com), November 24, 2001.

Steve,

I've been using my non-ttl leicas with an automatic flash (vivitar 385) when shooting chromes and it can work very well.

I haven't used the type of flash you have, but I assume it is similar to mine. According to a previous post you have two automatic choices, and depending on the film speed they tell you what to set your f-stop. Every automatic flash i've used (vivitars and nikons) tend to overexpose when you use the recomended f-stop. Because of this, when I use my flash for a main light I always set my aperture one stop smaller than what the flash says. When I'm using fill flash I will set it 1.5 or 2 stops smaller than what the flash says to use and it works great. Keep in mind that you must still expose for the ambient light of where ever you are to keep the background from becoming black. When you do expose for the background - underexpose it .5 - 1 stop.

Keep in mind that as long as your shutter is within sync speed, it has no effect on the flash. Set your aperature at the correct 1.5-2 stops below what it tells you to and adjust for the ambient light by adjusting you shutter. When you do this you will see that your shutter speeds can be very low (1/4-1/8 sec with 100 asa in a normal interior) but try it - you will be suprised what you can do. You may notice in many national geo shots that the background may have a slight blur because they are using the slow shutter speeds - but it looks much better than no background!

I took me qite a while and a fair amount of film to figure out the whole flash thing - and it can change when using different flashs. What I'm telling you are starting points. Try them out, if they work, cool, if not you can always tweak them a bit. I'm usually not very good at explaining things, so I'll give you an example of a typical fill flash situation:

I go into an intertior room with no nice white ceiling to bounce my flash off of. I first take ambient light readings with my camera meter (unless it's my M4-P!). With 100 asa it might be f1.4 and 1/30 sec. My auto flash, however, tells me it can only fire out f2 or f8 with 100 asa film. I choose the f2 setting and set my aperture for f4 (2 stops under what it tells me). To adjust for the ambient I would need to set my shutter now to 1/4 sec. I set my shutter to 1/8 sec (1 stop underexposed for the ambient) and I shoot away while holding my camera as still as possible. Using flash helps to freeze the subject, so it may be sharp while the background is a bit blurred (oftentimes a very pleasing effect).

Sorry to drag on, but hopefully it will help. I'll try to post some flash pictures I've taken so you can see how it works.

good luck! john

-- john locher (locherjohn@hotmail.com), November 24, 2001.

You can see some examples at:

www.photo.net/photodb/presentation?presentation_id=127695

(sorry I don't know how to make it link)

Some similar shots, but they may show how it works

cheers, john

-- john locher (locherjohn@hotmail.com), November 24, 2001.

This is what I have done for my Olympus S20: make a Sto-Fen-like diffuser using the translucent white plastic cut out from a film container. Just cut out the bottom of the container, slice the cycliner open and roll it out to form a flat sheet (with the help of hot air from a hair-dryer). Then bend it into a L-shape piece and cut it to fit to the top of the Olympus flash with a little double- sided adhesive tapes. The flash will work very well as a fill-in flash!

-- Hoyin Lee (leehoyin@hutchcity.com), November 25, 2001.

The S20 (my favorite flash for the M6!) has a dial on the back with positions for AUTO-1 and AUTO-2...

Just a follow-up: so the S-20 does not have variable output (like big flash units usu. do)? If you want less than full flash, you have to either change the ASA or stop down the aperture?

-- Tse-Sung (tsesung@yahoo.com), November 25, 2001.