well, that would be a case were I can understand feeling that you *need* to shoot wide open... managing OOF highlights is often difficult... have to work with the charactoristics of your lenses.
PetKal wrote:
Most of my lenses I shoot wide open at all times.
Can not stand those polygon shapes of OoF highlites.
mh2000 wrote:
well, that would be a case were I can understand feeling that you *need* to shoot wide open... managing OOF highlights is often difficult... have to work with the charactoristics of your lenses.
I was speaking kinda tongue in cheek.
However, there is one Canon lens where the EMD iris outline looks rather weird in the aperture range f/1.1 to about f/1.8. Consequently, when there are strong OoF highlites to be expected, I prefer to shoot the lens either wide open (f/1.0) or stopped down beyond f/2. Not the best lens design feature.
However, those are very singular circumstances. I do agree with you in the following way.....we all go thru a fast lens "discovery" process, sooner or later in our photographic experience. When I got the 85L my first thoughts were "How sharp is it wide open ?", "How smooth is the bokeh wide open?". Naturally, in pursuing answers to those questions I have taken hundreds of "only left eye in focus" photographs. After the novelty had worn off, I have also discovered that the lens is perhaps at its best at intermediate apertures.
Step in to the Tv side of force =) U will be amazed with results sometimes... and sometimes not :P
math is one thing but canon/nikon/sigma etc don't use 1/2 or 1/3 stop for most of the time. most lenses ar 2.8 4.0 4-5.6... not for ex. 3,5-5,6 or 4,5(500mm)...
but sensitivity of AF sensors cross type 2.8 rest 5.6 it's reason why to buy them... marketing ;P ;/
Just use apreture as U want/need/can not as coooooool f0,0001 or f12121.00 YeY :P
I mostly shoot manual. When I want a constant shutter speed, I will usually go for f/8 and dial in the appropriate ISO to give the desired shutter speed. As the light constantly changes, I will adjust the aperture up and down in 1/3 stops as required.
I know this sounds like Tv mode, but this way you remain in full control of the exposure.
Why use certain f-stops?
I prefer to use uncertain f-stops.
This is because my first interchangeable lens SLR (a sixties Miranda Sensorex) had lenses without aperture click stops. The aperture ring turned as smoothly as the focusing helical. There was TTL metering, and the match needle was in the viewfinder, leading to the bad habit of sometimes setting exposure without knowing what the aperture was.
Now I simulate this by spinning the thumb wheel on my Canons without glancing at the info in the finder.
Just kidding! But the description of the Miranda is accurate.
n0b0 wrote:
I see images posted here and elsewhere and most of the time the aperture people use are either the widest the lens has or it's f/8, f/11, f/16, f/22. I hardly see people saying their image was taken at f/7.1 or f/13 or other f-stop numbers.
Why is that? Is there something special about those four f-stop numbers apart from 8 being half of 16 and 11 half of 22? Just a beginner wondering.
I often use the 1/3 stops. I like to push the aperture say as far as I can while mainting a certain shutter speed and if that's f/6.3 or f/13 so be it. I actually use a number of my lenses 1/3 stopped down from wide open to get that little better sharpness.
It appears that many/most elect aperture priority and so, naturally, gravitate to whole numbers. When I use "program" the internal computer has no hesitation in setting the f stop to fractions.
As previously has been indicated the light falling on the sensor is dependent on the f-stop. Those mysterious numbers are just ratios. Full stops are the square root of 2 (1.41...) multiplied by the previous number (ratio x ratio). That's because the area of a circle quadruples with a doubling of the radius/diameter.
So all you have to do to move a full stop (down or up) is to multiply by either .7(07....) or 1.4(14....). So the sequence of 2, 4, 8, 16, 32 are two stop ratios and the intervals are the product of 1.4 times those ratios: 1.4, 2.8. 5.6. 11, 22 (just multiply 1.4 times two several times).
