Hi Fernando, As Peter suggested, considering the crop factor is a good idea. On the istDS I'm using a hood from a Takumar 123mm lens on the A50, and use the same hood on the 77mm. For the 24mm lens a much deeper hood than normal can be used - right now I'm using a hood from a 50mm lens, but later on today I'm going to try an even deeper hood. For a 35mm lens I've been using an afternarket hood that I've used on the K105 and the K120, and it shows no signs of vignetting. Experiment a little - you may be surprised at how deep and tight a hood you can use.
As for the cheap rubber hood, any hood is better than none, but you might be happier in the long run with a good, solid metal hood. One nice thing about the metal hoods is that you can find caps to slip over them, affording the lens some additional protection when in the camera bag or being carried around, without having to remove the hood from the lens and use a lens cap. Over the years I've used caps from cans of coffee, chocolate syrup, jelly beans, and so on. They're cheap (free!) and do a great job. Shel > [Original Message] > From: P. J. Alling > Yes the crop factor changes the angle of view, you should get a hood to > match that. > > Fernando Terrazzino wrote: > > > Hi, > > > > I just bought a 24-90 zoom to use in my *istDS and it didn't come with > > the hood. Now, my question is, should I get a wideangle hood or a > > "regular" one? I mean, should the crop factor "influence" the hood > > selection? > > Any one tried those cheap rubber hoods? Would that be good enough?

