Lens hood/Filter question

[SoulfulRecover]

Ive seen a lot of medium format cameras sporting rectangular lens hoods and filters clipped to these hoods or rectangular filter slides slid in place. Just wondering why this set up seems popular and why a round hood lens or round filter is not used. Probably a stupid question but had me wondering :er:

 

[Big Mike]

While the lens is round, the film is not. The film is square or rectangular. So there there are areas around the lens that could have more shading (hood) before the hood becomes visible through the lens (the long edges)....and there are areas that would take less of a hood before they start to vignette (the corners). So a rectangular lens hood covers more of the areas that can be covered. But more than that, I think you're correct that it has to do with filters and accessories that might attach to the hood.

Many modern lens hoods are 'petal' shaped, which maximizes the hood coverage, without vignetting.

You do still see round hoods, sometimes this is necessary because the front of the lens rotates, so a rectangular or petal shaped hood wouldn't line up with the shape of the film/sensor.

 

[SoulfulRecover]

While the lens is round, the film is not. The film is square or rectangular. So there there are areas around the lens that could have more shading (hood) before the hood becomes visible through the lens (the long edges)....and there are areas that would take less of a hood before they start to vignette (the corners). So a rectangular lens hood covers more of the areas that can be covered. But more than that, I think you're correct that it has to do with filters and accessories that might attach to the hood.

Many modern lens hoods are 'petal' shaped, which maximizes the hood coverage, without vignetting.

You do still see round hoods, sometimes this is necessary because the front of the lens rotates, so a rectangular or petal shaped hood wouldn't line up with the shape of the film/sensor.

cool! thanks for the explanation

 

[vintagesnaps]

I got a vintage Kodak square red gel filter to use shooting ir B&W film and got a holder for that so I could use it on more than one lens/camera (since I use vintage cameras too). I mostly have lenses that are either 52 or 55mm but beyond that I didn't want to get into another set of filters for just one lens or camera that I may not use a lot.

 

[cgw]

Bellows lens hoods are an extreme example--an adjustable hood that, in the case of the Mamiya RB/RZ, can work with 90mm-360mm lenses. They're very effective at flare-busting, especially with studio lighting. Most, regardless of brand, took gelatin filters(way cheaper than large screw-ins).