Project 1 and standard lens

I have had a look at project 1 and I am feeling a bit confused and argumentative – oh gawd! Already! The experiment itself and the title (Focal length and angle of view) seem to conflict. To find the standard focal length for my camera I am instructed to make objects in the viewfinder look the same size as in real -life. I am told that this is what is meant by standard. I am also told that on a 35mm film camera the standard is 50mm. As far as I was aware a 50 mm lens is a 50 mm lens and the perspective does not change whichever sensor it happens to be in front of (a full frame or a smaller 1.6 magnification). I get a cropped version with my sensor and all that changes is the angle of view. I’ve gone out and borrowed a full frame film camera to prove it. Having looked at the clock on my wall through the viewfinder of both cameras (with 50 mm lenses attached and from the same spot) I can confirm that the clock looks exactly the same size through both viewfinders – nearly life size. With the 35 mm camera I get a bigger overall view – I can see more of the surrounding wall but the clock is still the same size. (If I printed both photographs the clock from my camera would look larger than the clock in the 35 mm film print, but this is simply because mine is a cropped version printed at the same size as an uncropped 35 mm version.  An important point, however, is that the perspective and the spatial relationship between near and far objects remains unchanged)

On page 282 of the course material it says that the standard focal length for a camera is less than 50 mm in proportion to the smaller size of the sensor ( For mine this would be 50 divided by 1.6 which equals 31.25) – Fair enough, but this is the comparable angle of view and I am not going to arrive at this figure by following the experiment in project 1 and matching the size of the clock in my viewfinder to the size of the clock on my wall.  To arrive at this figure, without the mathematics, I need to match the full angle of view and not the size of objects to real life! (By the way, I would not be able to match the angle of view if I hadn’t borrowed a full frame camera – I wouldn’t have known what the angle looked like).

Conclusion

If I match the size of objects and the spatial relationships to real life, as I seem to be instructed, the answer is about 50 to 60 (the same as full frame) but if I match the full angle of view, the standard focal length for my camera is about 30 (with a much smaller clock in the viewfinder).

To top it all I think that 60 mm give a better natural perspective then 50 mm (on both cameras).  I think the true answer to this question must be as follows: If I want a natural looking perspective I should choose a focal length of between 50 and 65. If I want to achieve the same angle of view as a 50 mm lens on a full frame, then I would choose a focal length of approximately 30 mm.  (Although this photograph would have the same angle of view, as far as I can see or judge, it will not (appear to ) have the same perspective. I can see this by looking through the viewfinders. Objects in the distance look much further away in my viewfinder when viewed at 30 mm) To prove it on here, I will need to  buy a film,  learn how to use the 35mm camera and display the two different photographs.  This will be done at a later date. For now I am going to have to move on because at this rate I am not going to get through the projects and the assignments.