Say Cheese! Pt 3 (Photography Reflection)

Hello all.

Thanks for the depth of field information Sophie; I was a bit confused myself. Reading the Wikipedia article made my head swim! But am I right in thinking the following?

• The larger the depth of field, the more of the image in front of and behind the focus point is also in focus. Therefore, for intra oral shots the larger the depth of field the better.
• The depth of field can be increased by increasing the lens f-number (a setting on the lens). Therefore for intra oral shots we should set the lens f-number to the largest value available on the lens.
• The ‘aperture’ is the diameter of the opening that allows light into the lens. The aperture is decreased by increasing the f-number. Therefore the smaller the aperture the better the depth of field.
• A macro lens is used for intra oral photography because it is ideal for close up shots. However, macro lenses have a long focal length. A lens with a shorter focal length will give a greater depth of field.
• The closer the camera is to the subject, the smaller the depth of field. Therefore, to increase the depth of field the camera should be positioned further away from the subject.

Are these correct?

I also wanted to clarify what is meant by the term ‘focus point’ on the self assessment table. Is the focus point what the camera is aimed at (i.e. the object in the middle of the photo), or is it the centre of the depth of field (i.e. the least blurry depth of the photo)?

Thanks. I hope this all makes sense!
Nick