just make sure you know what speed your film has effectively been exposed at as there is very minimal control with the camera. or example in overcast weather my film speed was effectively 800 as that was teh EI required to give a correct exposure at teh fixed speeds of teh holga. I therefore shot TriX and push processed in Xtol. The weather was fairly grey and steady so at least all shots were similiarly exposed. The Holga will give all sorts of trouble if the weather is bright, then dull, then sunny then flat....that said, eriously overexposed negs are less of an issue as holga images tend not to be printed too big so if some are overexposed its no bother.