Not Sure what I purchased
Recently I purchased Used Sigma 28-80 F3.5.-5.6 Aspherical. for use on my Nikon D5300 and/or D3200.
I attached the lens and had to set the lens to the smallest f-stop. no real explanatin why. so far I have only managed to get it to work for macro in mf .
Being a bit of a knob with some older eqipment I have little idea of what to do, to be able to use a normal zoom also as macro.
Starting to think I made an error . not that expensive so can put it down to ignorence
I attached the lens and had to set the lens to the smallest f-stop. no real explanatin why. so far I have only managed to get it to work for macro in mf .
Being a bit of a knob with some older eqipment I have little idea of what to do, to be able to use a normal zoom also as macro.
Starting to think I made an error . not that expensive so can put it down to ignorence
Quote:I attached the lens and had to set the lens to the smallest f-stop. no real explanatin why.
The camera controls the aperture. If the lens was set to, say f8, and the the camera needed ito go to f11 for correct exposure - the lens setting of f8 would over-ride the camera. Hence, by setting the lens to the highest f number the lens has, the camera then has the full range to work with. That is normal with Nikon A/F bodies.
Sorry, but I do not understand the rest of your query.
If the fstop is too small, then isn't it too dark to focus using AF.
Does AF not need a wide aperture to focus before it stops done to take the shot.
Or was that just Canon.
Does AF not need a wide aperture to focus before it stops done to take the shot.
Or was that just Canon.
The aperture on a lens is usually wide open which gives a bright viewing screen (on a DSLR) and helps the A/F. It is when the shutter is pressed to take the image that the aperture closes down. If the aperture on the lens is not set to the highest f number it could restrict the diaphragm from stopping down as far as is needed for correct exposure, as I explained above. I hope this clarifies it.
