So let's say you shoot a portrait with the same lens but you shoot the second picture in crop mode ( from further to get the same framing): the background blur at infinity will be the same but you will have deeper dof in crop mode. Second: no you can not simulate a 85mm f/1,8, no miracles, sorry ! By cropping you simulate a 85mm f/2.7 which has in fact the same separation power. If you shoot a portrait with the same framing (so not from the same distance), the background blur at infinity will appear more blurry for the 85mm lens A 55/1.8 has more separation power than a 27/1.2 though the last one has a lower f#. The ratio 55/1.8 gives you a kind of separation power for a lens. dof for a given subject framing depends on f#.
Background blur (at infinity in fact), for a given subject framing depends on the physical aperture size, thus the ratio 55/1.8. On the other hand, if it could be appreciably improved with the 85 mm - well, it wouldn't take much to give in to GAS.įirst: i think you are more interested in background blur for subject separation than dof, this is a bit different. I think I could make the separation work.
#Bokeh full series
So, to determine if dof separation would be acceptable with the 55 mm in apsc mode, I took this series of shots with my a7Riii. Avoiding the extra weight in an already hefty pack and lens changing would be a benefit. My aim, of course, is to use my 55 mm f1.8 for candids on the street and avoid spending another $600 for an 85 mm f1.8. Yes, I'm most interested in depth of field for separation of subject from background, and not so much in the subjective nuances of bokeh.
#Bokeh full full
But usually most prefer full circular bokeh balls edge to edge with smooth rendering inside. But usually the best FF lenses are better than best APS-C lenses also in bokeh, much easier to design also.īokeh is also somewhat personal subjective. There are lenses in both APS-C and FF having good bokeh. So, no, you wouldn't have the same DOF in full frame and crop modes with your A7RIII and 55/1.8 at 1.8 shooting the same subject from the same distance.īokeh is a character of lens. With the same lens, at the same aperture, cropping decreases the depth of field because you're effectively increasing the magnification. I think your question is about depth of field, though. How much and what kinds of CA present on OOF edges, etc. Whether lines get jagged or are duplicated. Whether points become bubbles or cats' eyes or some other shape. Correct?ĭOF and Bokeh are not the same thing, though they are related.īokeh is the rendering of the out of focus areas. To get the bokeh of an 85 mm f1.8, I would need to use that specific lens.
I would get the same bokeh with my 55 mm f1.8 on my a7riii whether in full frame or APSC mode, since APSC is simply a crop.
0 kommentar(er)
