1.6 Crop Factor question...

Just keep this simple fact in mind and you'll be fine.

The mounting system doesn't change the focal length of a lens any more than it changes the weight or length - all 3 are intrinsic physical properties.

So 50mm is 50mm, optically, regardless of what's hanging off the back. If you are using a camera with a 1.6 "crop factor" sensor, you will do they math you described.

There are many more details, but I think some of the answers above started trying to explain them and just confused things.

A related question...

For full-frame cameras, the rule of thumb for hand-holding a lens (ignoring image stabilization) is to shoot no slower than 1/FL, where FL is the focal length of the lens. For example, you should be able to comfortably hand-hold a 200mm lens if you use a speed of at least 1/200.

For crop cameras, like the 60D, is it still 1/FL or is it 1/(effective focal length)?

migla9 said:

A related question...

For full-frame cameras, the rule of thumb for hand-holding a lens (ignoring image stabilization) is to shoot no slower than 1/FL, where FL is the focal length of the lens. For example, you should be able to comfortably hand-hold a 200mm lens if you use a speed of at least 1/200.

For crop cameras, like the 60D, is it still 1/FL or is it 1/(effective focal length)?

Click to expand...

Oh no, you may have reopened a bag of worms from a recent thread.

Anyway, use the "effective" focal length (1.6*FL) as the denominator. I simply use 1/(2*FL). If employing an IS lens, I calculate the 3 or 4 stops that it gives me from the rule of thumb value.

Thanks, that's what I was thinking. While the image displacement (amount of jitter) from a handheld lens would be the same on a full frame sensor and a crop sensor, the crop sensor image needs to be 'enlarged' to get the same FOV. The same increase that gives the effective FL also increases the apparent jitter, necessitating a faster shutter speed. Am I thinking about this the right way?

One item to consider, however it is a pain if you do a lot of wide angle shooting, is the canon or adobe stitch program works great. I am in the same boat, I shoot a lot of wide angle and am in the process of purchasing a 8-16mm Sigma super wide angle. I have been doing quite a bit of stitching and it gets to be a hassle!!. The 24-105 is a great lens but @ 38mm it is not very wide angle.
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Steinr98

migla9 said:

Thanks, that's what I was thinking. While the image displacement (amount of jitter) from a handheld lens would be the same on a full frame sensor and a crop sensor, the crop sensor image needs to be 'enlarged' to get the same FOV. The same increase that gives the effective FL also increases the apparent jitter, necessitating a faster shutter speed. Am I thinking about this the right way

Click to expand...

Yes...
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regards
Karl Günter Wünsch