Still on the subject of flash photography using ISO 100 film, let me point out that entry-level models like the EOS 300 (EOS Rebel 2000) and its predecessor, the EOS 500N (EOS Rebel G), both of which are Type A cameras that utilize E-TTL illumination with any EX-series Speedlites, have no problem in obtaining perfect flash coverage indoors or nighttime conditions even with budget-priced EF zoom lenses if the original method (Full Auto) fails. If you don't like the harsh shadow effect given out by these cameras in their Program E-TTL modes via direct flash, you can always opt for bounced E-TTL, even with ISO 100 film and budget-priced EF zoom lenses on ISO 100 films. This photo below of a small presentation was shot this way. The E-TTL method also retained the greenish effect of the fluorescent lighting, as can be seen from the overall atmosphere, despite the bounced effect. For those using Type B EOS cameras, like their Type A counterparts, when the background is already dark with little or no ambient illumination, there is nothing the EZ-series of Speedlites can do to brighten up the scene other than providing the fill-in for the main subject, like the shot of the beauty finalists above, photographed in Tv mode via TTL flash. The difference between both of Canon's E-TTL and TTL flash metering is the former retains not only the ambient lighting on the background but also on the subject while the latter provides daylight-balanced illumination on the subject and allows the ambient light to remain in the background. See the examples below. E-TTL flash illumination in Tv mode TTL flash illumination in Tv mode Having said all that, there are times when using higher ISO film speeds will get better results indoors and in nighttime shooting conditions with either the built-in flash or external Canon Speedlites, especially for those who do not have one of those reasonably-priced Ring USM EF lenses or the L-series versions. The higher ISO speeds will allow you to have an extended flash coverage for your variable aperture EF zoom lenses. This is in addition to greater depth-of-field, if you are keen to explore the possibilities of shooting indoors with Av mode, using settings like f/5.6 at 1/15 sec. and f/4.0 at 1/30 sec. Super fine grain, excellent level of sharpness and details in the films are probably not that important for most beginners and amateurs as they are more concerned in getting the shots right, rather than be disappointed by mediocre results due to wrong settings or incorrect usage of the techniques. In this case, preferring to use a higher ISO film speed over an ISO 100 film would be a logical choice for them. << Back to Main . 1 . 2 . 3 . 4 . 5 . 6 . 7 .