Originally posted by DeadJohn Weevil wrote "Aperture 1/3 to 1 step stop down from max aperture". In that context "max aperture" means the widest and largest aperture which I think is f4.5 for your lens. 1 stop down from that would be f6.3.
You might be fine at f8. Most lenses are sharp there. You get more depth of field than f6.3 which is more forgiving for focus. In dimmer light, though, rather than staying at f/8 and boosting ISO or slowing shutter speed, you can try to change the aperture.
P.S. Aperture f-stops are counterintuitive when learning. Larger numbers = smaller opening.
Yeah.... it's fine. Perhaps it's just a case of understanding how to use the terminology. I was taking it from the perspective of numbering rather size of the diaphragm
---------- Post added 04-28-22 at 10:38 AM ----------
Originally posted by Des I would just add three things to this:
1. The FA*300 is good wide open (f4.5) but a bit better when stopped down (ie narrower aperture) by two-thirds of a stop (f5.6) or one stop (f6.3). That is the sort of stopping down that @Weevil is referring to. (With lower quality lenses you may need to stop down more to get decent resolution.)
2. The difference in depth of field between, say, f5.6 and f8 (one aperture stop) can be significant if the subject is reasonably close (hence more leeway if focus is not perfect) but the significance diminishes as the subject is further away. For example, using the FA*300 on a K-1ii, DOF at 10m to subject is 307mm at f5.6 and 520mm at f8. At 20m to subject it is 1490mm at f5.6 and 2110mm at f8. (
https://www.photopills.com/calculators/dof) At that point you would be better to use f5.6 rather than f8 (that is, one stop wider aperture) and reduce the ISO by one stop (ie halve it - e.g 1600 -> 800) or increase the shutter speed by one stop (ie double it - e.g. 1/500th -> 1/1000th).
3. You might already know this, but if you narrow the aperture beyond a certain point, resolution deteriorates because of diffraction. With the FA*300, it probably falls off beyond f8.
BTW, great examples @DeadJohn @Weevil @Redpit
Yeah, once of the tests I made myself ages ago was to shoot a light source. At first wide open then stop down and see how the image behaves. The size of the diffraction spikes was another tell tale sign.
As to DoF, my recent experiments with macro have taught me a lot about using the aperture setting both mechanically and creatively.
With astro imaging it's not so important as you really want to be wide open as much as possible and really only close the blades to get a bit of extra sharpness. Of course the effect this has is to let less light through the lens and into the sensor. Not something you really wana be doing when shooting a remote galaxy 3.5 million light years away.
Though astro is way more technical in terms of equipment and processes used - especially when using flat, bias and dark frames.
---------- Post added 04-28-22 at 10:43 AM ----------
Originally posted by mlag I think indeed that you need to get closer to your subject if i see the last 3 pics....your hit range will improve if four subject covers more focus points, like the central 5 / 9 points or so, bit camera dependant. Or divide your viewer in 3x3 rectangles, ideally the subject should reaonably fill the central one..otherwise you need to crop too much afterwards impacting quality. A consequence of this rule is that you need to get really close to small birds....and less to larger birds or ....an elephant or so...
For airplanes at low altitude you need to get closer to airport’s approach or take-of routes...for birds you need patience to get close to their habitat, might need to keep low profile or hide, have patience till they come back,
sometimes it is easier if you can start aiming from take off from their nest or other departing point...
One could also try 500mm tele or more, but aiming gets more difficult on moving targets...
Birds aside, I'm actually just over a take-off route for planes. Though even large planes like the Boeing 777/787 might be still a little small for my 300mm. Maybe 500-600mm focal length might be better from my currently location. Will need to try near the airport for a better experience. I actually would be quite interested to see how my 24mm, 150mm and 300mm behave out there
---------- Post added 04-28-22 at 10:59 AM ----------
Yesterday and today I tried AF again with difference style targets.
I think I'm happy with these guys:
DFA28-105mm @ 105mm. EXIF: 1/2000s, ISO 400, f/8, using internal HDR mode on AUTO
_IMG0804.jpg - Google Drive
I think it's a JAL 777
FA*300mm @ around 65ft/20m, EXIF: 1/1000s, f/8, ISO 6400
_IMG0829.jpg - Google Drive
As I only use M or B modes, I played around the automatic exposure modes today for the first time. This one was either on Av or TAv mode (can't remember exactly).