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Just1MoreDave · 07-01-2009, 11:00 PM

Originally Posted by stl09

This may be a stupid question but what would be the difference between these two lenses? I know the f-stop is the same for both. Does one lens allow you to get closer to the object over the other.
I'm trying to figure what the advantage would be to have one over the other or should one have both lenses for macro shots?

Thanks,
Kevin

First, for comparing macro lenses, reproduction ratio is at least as important as focal length. If the 50mm and 100mm lenses can both achieve the same reproduction ratio, you can probably take the same shot with either one. You must get closer with the 50mm lens than the 100mm lens.

With a 50mm macro, size or weight is an advantage. These lenses are only a little bulkier than a non-macro 50mm prime lens. But getting extremely close is not always possible. Using a flash to add light may be more difficult because the camera and lens are in the way. Using a tripod may be impossible at those distances. On film, a 50mm macro might replace your 50mm normal prime kit lens and be the only lens you'd need. You could still do that with the Pentax DA 35mm f2.8 Limited macro, I suppose.

A 100mm macro can be inconveniently large, but worth the trouble if you need increased working distance. If you only have the shorter macros and need distance, you can only back up and end up shooting at a lower magnification.

For your first macro lens, think about what subjects you want to photograph, at what distance, then pick the best lens for that.

07-01-2009, 11:00 PM	#6
Just1MoreDave Pentaxian Location: Aurora, CO Gallery Photos: 1 Posts: 789	Originally Posted by stl09 This may be a stupid question but what would be the difference between these two lenses? I know the f-stop is the same for both. Does one lens allow you to get closer to the object over the other. I'm trying to figure what the advantage would be to have one over the other or should one have both lenses for macro shots? Thanks, Kevin First, for comparing macro lenses, reproduction ratio is at least as important as focal length. If the 50mm and 100mm lenses can both achieve the same reproduction ratio, you can probably take the same shot with either one. You must get closer with the 50mm lens than the 100mm lens. With a 50mm macro, size or weight is an advantage. These lenses are only a little bulkier than a non-macro 50mm prime lens. But getting extremely close is not always possible. Using a flash to add light may be more difficult because the camera and lens are in the way. Using a tripod may be impossible at those distances. On film, a 50mm macro might replace your 50mm normal prime kit lens and be the only lens you'd need. You could still do that with the Pentax DA 35mm f2.8 Limited macro, I suppose. A 100mm macro can be inconveniently large, but worth the trouble if you need increased working distance. If you only have the shorter macros and need distance, you can only back up and end up shooting at a lower magnification. For your first macro lens, think about what subjects you want to photograph, at what distance, then pick the best lens for that.