Troubles with Nikon D70s SLR

[Jason McK]

Originally Posted by R.A.D.

Photography is best learned through trial and error. Formulas in my opinion does not really help in understanding how the camera and lens work together.

I 100% agree. During my career I have had 100s of people ask me how to become a pro photographer. I always say go to business school and shoot every day.

Half way through this thread I realized that what I'm talking about only relates to Marco photography where the subject is being exposed at a ratio of 2:1 or greater. Meaning the exposed image is 1/2 the size of the original or larger (the Image is actually larger than the original subject). For example if you where to take a picture of 1 polyp of an SPS or LPS and fill the frame with that polyp the actual image would be larger than the subject. The closer you get to a 1:1 ratio the less F-stop effects DoF. So in reality with the tank glass and the distance from the class to the subject it would be very uncommon to get such an instance where this would play a significant role.
But having said that. A true macro lens does not react the same way your standard 50mm or what ever does in terms of DoF. the Classic DoF experiment would be to take a standard lens and stand at a picket fence. focus part way down the fence and then take exposures adjusting the aperture between each frame. This shows the effect of DoF. Now if we were to shrink this test and say set up dominos on the floor and perform the same experiment with a Marco lens you would never achieve the same degree of DoF regardless of f-stop.
Just for some background I too took photographic sciences in school. But instead of taking pictures we built emulsions on glass plate, Built lenses and shutters. then created images from what we constructed.
I still work in the industry but gave up on shooting years ago.

J