How valuable IS TTL flash?

I'm thinking of buying an external flash. Since I'm driving an Oly

E500, the only TTL that works with it is an Oly (they look a LOT like

Sigmas to me). I've never used TTL Flash (do the pathetic built-ins

count?)so I don't know if they are worth the premium that is charged

for them.

 

I know how to operate an electronic flash manually, but I'm at the age

where I AM willing to pay for a little extra conventience, but I've

been around long enough to know not all "Conveniences" are worth the

money. And I suspect electronic flash is an area where inadequate

performance may not be noticed by a large number of people.

 

I hope some people will give me their opinions on this and maybe some

other Oly owners who have opted to not pay for TTL have fared.

I don't use Oly cameras, so I can't help you there. I have noticed they want a lot of money for their flashes though.

 

Using an auto flash still provides the same accurate and reasonably consistent exposures it always did. Digital capture is a bit more fussy about getting the exposure right, something like shooting with slide film, but since you can see right away what worked and what didn't you can make adjustments and shoot again. For most uses auto flash is at least as good as TTL. In some cases auto flash is even more consistent and predictable.

 

TTL has some advantages with long lenses and very wide lenses. And if it is designed right and you take advantage of its features you can get more accurate exposures with off center subjects when using TTL. But again, it is simple enough to make compensations with auto flash, or even manual flash and get just as good.

 

With auto flash you (generally) have to set your ISO on the flash, choose an auto range, and set your lens to the indicated aperture. With TTL you can just shoot.

 

TTL is easier, but it isn't necessarily better.

TTL is a blesssing. But most digital P&S don't offer TTL, even with their own expensive hot shoe flashes.<br>I shoot EOS bodies and TTL flashes <i>made by Canon for EOS bodies</i> are consistent and nearly fool-proof as long as you stay within 65-75% of their effective range <i>at aany given lens setting, though ``<i>A`` TTL or ``E`` TTL</i> flashes are sometimes problematic when you're shooting a DLSR.<p>The best, nearly trouble free flashes I <i><b>ever</b></i> used are the auto-Thyristor Vivitar 283, 285 & 285HV breed.<br> The Vivitars (mostly 283s) shot millions of Weddings and events long before TTL flash took us old time manual flash shooters out of the literal darkness.<p>TTL flash is a good thing.</i><div></div>

TTL flash provides much better exposure, imo, than auto flash. And as already mentioned, the digital camera's limited dynamic range and sensitivity to over exposure makes it even more valuable.

 

I've been shooting flash since the days when you could buy a new Honeywell flash unit. I'd never go back to auto.

 

larsbc

</i>I've used manually calculated flash, hand metered flash and auto thyristor flash. All can work well or at least well enough for a given situation. But good TTL flash can do it more easily.<p>

 

The first TTL flash I used was on various Olympus cameras: an iS-2 "ZLR", C-3040Z digicam and a couple other digicams. I was impressed enough with the convenience and good results to make TTL flash a priority in my next major purchase, a dSLR.<p>

 

After shopping around I decided Nikon's new CLS flash system would meet my needs. I got a D2H and SB-800 and haven't been disappointed. It's very easy to get good results quickly using full auto everything - Program metering mode on the camera, iTTL-BL flash for balanced fill flash, sometimes dialing in +/- EV on the flash. It's close enough to P&S simplicity that I can hand the camera to someone else and they'll get well exposed photos.<p>

 

There are all kinds of ways to finesse the flash. Removing the BL (balanced fill flash) option gives you more control. Regular TTL and iTTL-BL tend to produce up to a one stop difference in results - neither is better, it just depends on the circumstances. Results are far more consistent and repeatable than auto thyristor flash, even when photographing a bride in white gown and groom in black tux.<p>

 

Nikon's CLS system offers a few other nifty features that are sometimes overlooked, such as FV lock. This enables zooming in on the primary subject for perfect flash exposure via a preflash. Then zoom out or recompose and the primary subject will still be perfectly exposed (as long as both the photographer and subject remain at the same distance).

 

Anyway, I'm not sure what Olympus offers in TTL flash for their dSLRs, but I've long been impressed with the quality of Olympus TTL flash from P&S type cameras.

I don't have Oly cams. And, I kinda skipped over TTL.........I went from the generic manual or auto flashes to Canon's ETTL....so, again, things might be different for normal TTL...don't know.

 

Anyhow, after much playing around with Canon's system, I have found that it's best to handle the ambient light in the Manual camera mode (I can control the amount of light in the background, to an extent, this way), and the ETTL flash in it's ETTL mode (for the actual subject).....assuming your cam allows this. Canon's do. AND I tend to flash exposure compensate by -1 stop.....not always, but that's where the default is set. Again, this assumes you can exposure compensate your flash seperately from the ambient light source manual mode.

 

Very strange set up to get used to coming straight from manual and auto flashes, but it does work once you get the hang of it.

I can speak for the Oly side (E-1 user) and use the FL-36 myself. The TTL works relatively well with a slight tendency towards underexposure which is preferable to the alternative as you can boost highlights but cannot create ones that are blown out. The biggest advantage is the TTL "FP" mode which allows the use of higher shutter speeds when using fill-flash outdoors. You can remove shadows on faces while the camera meters the shot. For everyday use (shutter speeds up to 1/180) the FL-36 in TTL mode is a great performer (and it's not bad in straight auto mode either). For longer range use, I have found my trusty Sunpak 522 handle flash with the optional remote sensor to be the true winner. Not a digital reading on it (all analog dials) but dead-on exposures every time, and range to 40+ feet. I believe the current model is the 544 (I'll be quickly corrected it I'm wrong).

TTL flash can be a huge help. Figure that with TTL, you are reading the light that counts. Any other way of doing it is making some kind of an assumption that the light being read is exactly proportional to the light reaching the film or digital sensor.<BR>

Not that TTL can't get fooled, but anything that will throw off TTL will throw off auto flash -and plenty of things that will throw off auto flash won't affect TTL.

<P>

Things like:<BR>

Filters -on the lens or the flash<BR>

Zoom -varying effective aperture of the lens and changing the field of view (which can include or leave out very bright or dark areas which the flash sensor will read, but aren't in the frame)<BR>

Bounce flash<p>

 

All will contribute to exposure error with auto flash, but are automatically taken into consideration with TTL.

<P>

If you use a prime lens without filters and don't bounce flash, auto flash will do an excellent job.

<P>

As with any exposure system, a subject that -in the average- is significantly different from 18% gray is not going to get properly exposed whether TTL or auto (though there are some exceptions, like Minolta's ADI, but all that stuff is an entire subject in itself...)

... Hmmmm... I probably shouldn't have said Bounce Flash (as a factor that throws off auto flash but not TTL), but I could have added bellows or extension tubes.

Going back to your question about external flash as well as TTL, I'd observe that the ability to place the flash on a bracket, or hold it away from the camera with a connecting cord, provides a real advantage over a little on-camera winker in terms of avoiding redeye, dropping shadows behind your subject, and facial modeling. External flash usually offers more power as well as bounce or diffuser options. Indoors, where the flash supplies virtually all the illumination, TTL never showed me any compelling advantages over auto flash. TTL earns its keep outside with the ability to integrate flash and ambient exposure for daylight-balanced fill flash--a real benefit.