hi...i have just gotten a graflite 3-cell unit #2773 with 5" & 7" reflectors & have a question about the difference between press 40 & #5 bulbs. i know about the difference with the base & size of the bulbs. my question is more towards practical in-use regarding the strength of the bulbs and if there is anything different required in determining correct aperture & shutter speed. or do i just rely on the guide#'s of the bulbs? in what lighting situations would each of these bulbs be more/less appropriate? i'm assuming the 40's are brighter bulbs for lower-light scenarios. is this correct? any help is appreciated. thanks,george c.

<font size=-1>[ This Message was edited by: sobahguy on 2002-01-10 10:19 ]</font>

<font size=-1>[ This Message was edited by: sobahguy on 2002-01-10 10:20 ]</font>

From info in the main part of this site. The press 40 and #5 have about the same guide number. Example 1/200 sec ASA 100 the press 40 guide number is 160 with a 7 inch reflector. For the #5 same setting using the 5 inch polished reflector the guide # would be 190. The 7 inch reflector will have wider coverage. This means that at 10 feet you would set your Iris to F-16 for the press 40 and stop down just a little more for the #5.Russ