David, It seems you are confused about the TTL. I'm not sure what you mean by "True". Basically TTL means that the camera body meters the film plane for correct exposure and turns the flash off when there is enough. The big advantage is that you can choose any f-stop you want within the power range of the flash. Using an A lens on A setting will only accomplish the camera setting the f-stop for you. The net difference of using an A lens set to 5.6 and an M lens set to 5.6 is nothing. Of course, letting the camera set the aperture for you somewhat defeats the reason for TTL. You could have just as easily use the flash's sensor in A mode.
So, in summary, you don't need any A lenses to get TTL benefit. Pick your F-stop and go for it. Bruce Wednesday, December 4, 2002, 9:25:55 AM, you wrote: DB> A good friend is getting married in January 2003,he DB> for the 3rd time,she for the second.I now have the SP and DB> 280t flash (smc m50 f1.7) on it for now.Hope to have the DB> a 50 f1.7 before the wedding. DB> I have done a bit of experimentation with the camera/flash combo DB> and m lens,flash on TTL and using several f stops on the 50 DB> 5.6 and 4 mostly.Test shots look good. DB> My ? is: >>Would i be better of using the A lens for "true TTL" or DB> will i have just as much success with the M set at f4 or 5.6. >>The request is for some simple shots,aisle,some alter and the DB> smootch etc.I plan on doing better than that ,but would Portra DB> 160 NC be better in this case than VC.Location is a country club DB> setting with fireplace.Light unknown but probably good. >>I got suckered in,how do you say no to a 6'2" big person.<G> DB> Thanks DB> Dave DB> Pentax User DB> Stouffville Ontario Canada DB> http://home.ca.inter.net/brooksdj/ DB> http://brooks1952.tripod.com/myhorses DB> Sign up today for your Free E-mail at: http://www.canoe.ca/CanoeMail
