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Originally Posted by Christine
Andy,many thanks for a simple explanation.Just one question please,stepping down the aperture,does that mean the F stops,and how many stops would you suggest for a bright sunny day,using the 1x4 on say the 400F5 (non is lens).Now you have given me a few tips Andy,will read the cam manual and check out apertures.
Thanks again.
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Hi Christine,
Andys comment on shutter speeds is very relevant.
If you can tear yourself away from taking pictures of birds for a while, you can do a few test shots to view on your screen.
Three seperate tests here.
1) With some converters there may be a softening of the image at the sides at full aperture and stopping down one or two f stops will solve that.
So for this you will need a flat object that has detail that would show this effect. A flat panel fence, brick wall, or similar. You MUST tripod mount your camera so there is no shake, line the camera up as square as you can. Select aperture priority and start at the widest aperture. Take a pic. Select 1 stop down and take another, etc So your range would be f4 followed by f5.6 and then f8. You should not need to go further than this.
2) Select an object that has depth and would record sharply in a picture. Even something rested against a brick wall will do here, broom handle is ideal. This test is to show The effect stopping down your lens will have on the zone of sharpness. Set yourself up at least 20 feet away at a fairly sharp angle. Again this is a tripod job. Focus on that object. Set up as before. Aperture priority. f4 then f5.6, f8, f11. When you view these images you will see the zone of sharpness increases as the lens is stopped down.
3) Your the effect of shutter speed when handholding is the last one.
As your set up will greatly magnify your subject so it will also magnify the effect of camera shake. For this any object with sharply defined detail will do. Set your ISO to at least 200, camera on shutter priority, take a set without your converter going from 1/1000 down to 1/250. Repeat with the converter attatched. This should show how slow you can afford to set the shutter speed and handhold for sharp results with your telephoto and with converter attached.
With those results in, it is a case of setting an ISO rating that will allow the setting of sufficent shutter speed for shake free, and aperture to achieve your desired zone of sharpness.
You just have to tear yourself away from the birds for a bit to do it !!
Don