John151
Wednesday 14th September 2005, 07:33
Has anyone had any experience with this guide?
I purchased one the otherday and the instruction manual states "Note: for digital SLR cameras, the actual focal length of the lens is required to calculate the depth-of-field, not the equivalent focal length that results from less than full frame sized digital imaging chips. So ignore the multipliers, crop factors, etc. commonly referred to for the purposes of determining depth-of field."
In view of the extra magnification required with smaller chips these instructions did not seem reasonable to me, so I questioned this with the suppliers. They replied quickly and sent me an updated copy of their FAQ which gives a table of equivalent focal lengths to be used with smaller chips. For 20D users this means multiplying the actual focal length by 1.25 to obtain the value to be used with the Expoaperture depth-of-field calculator. With this additional information I am very pleased with it and I think it is well worth buying if your lenses, like mine, don't have DOF markings.
I don't like the Depth Mode on the 20D. It is quite often difficult to line up the focus points on the nearest object and infinity simultaneously. I prefer the method used on the EOS 30 where you press once on the nearest object followed by once on the distant object, then take the picture.
I purchased one the otherday and the instruction manual states "Note: for digital SLR cameras, the actual focal length of the lens is required to calculate the depth-of-field, not the equivalent focal length that results from less than full frame sized digital imaging chips. So ignore the multipliers, crop factors, etc. commonly referred to for the purposes of determining depth-of field."
In view of the extra magnification required with smaller chips these instructions did not seem reasonable to me, so I questioned this with the suppliers. They replied quickly and sent me an updated copy of their FAQ which gives a table of equivalent focal lengths to be used with smaller chips. For 20D users this means multiplying the actual focal length by 1.25 to obtain the value to be used with the Expoaperture depth-of-field calculator. With this additional information I am very pleased with it and I think it is well worth buying if your lenses, like mine, don't have DOF markings.
I don't like the Depth Mode on the 20D. It is quite often difficult to line up the focus points on the nearest object and infinity simultaneously. I prefer the method used on the EOS 30 where you press once on the nearest object followed by once on the distant object, then take the picture.