Distance to the background or the foreground.(p.25)Īll the parameters listed here influence the phenomena outside the focal plane: (List p.25) In photography the term ”confused“ relates naturally to light beams which no longer come together at a single point in an orderly manner. The root of the Japanese word 'boke' or 'bokeh' actual means nothing good its meaning is similar to 'confused' or 'dizzy' and is used to name mental states in exactly the same way. (p.17) I hadn't thought of it this way, but I guess that makes sense, although it is a bit like saying 'when all things are equal, everything is the same' In fact there is a table of equivalent f/numbers for different sensor sizes (p.10)Īll formats have the same depth of field at the diffraction limit. (p.9) - this answers/confirms the FF DoF thread question Reducing the size of the film format therefore reduces the depth of field by the crop factor. Nasse) put in bold himself.ĭepth of field is based on the acceptable blurriness and is therefore essentially based on arbitrary specifications. I have extracted the pertinent sentences, usually the ones the author (H. ~ have you a quick summary for those of us less inclined to delve into Zeiss's reader friendly treatise? OK, I'll bite as Robin seems unwilling With a bird shot against the sky, it is fine, but put some sunlit light-straw coloured grasses behind it and it can get nasty, definitely requiring the application of sharpening selectively on the subject only, if I don't want to make it 5x worse.ĮDIT: Whoa Robin, I'm gonna need a coffee and a clear head to read your link, but that looks very educational from the quick skim I have had so far. It is the first I have seen that mentions the double edge on linear highlight picture elements and shows it - this is an area I find a problem on the Nikon 70-300mm, although I obviously need to test at various apertures and focal lengths.

Not seen that before, apart from being a little dated in terms of lenses tested, it is, as you say, very good with practical demonstration images.

The article uses testing to demonstrate what bokeh is (I've referenced this article several times, and I suspect that many people don't follow it right through - it took me a few tries). There are no measurements for bokeh so it is somewhat subjective, however it is real, and bad cases of bokeh are really bad. Although the following article is called Bokeh Test, and it comes as close as any to defining bokeh (sometimes spelled boke), or at least it shows what it can be.

Bokeh definition