Hello Nogbad,
All of what has been said already is relevant, I think you may be a little optimistic with your ideas of what can be achieved. Knowing the Abberton causeway, I wonder how far away your subject was? A zoom lens will bring things closer, but there are limits. If your subject distance is short the optics won't be "on the limit" so much with regards to what they have to resolve. Another thing is the amount of light available. It was sunny in the causeway on Sunday afternoon with a nice sharp light, this will help. If it was dull at the time you took your pictures they won't have the same "snap", regardless of the settings and equipment used.
The lens is being used at full zoom which will probably make the images a bit on the soft side, adding a 2x telecon will make things softer still, the max
effective aperture will be small but presumably the actual aperture on the lens was wide open. This again will not lend itself to the sharpest of shots. Add in the camera shake you will get at shutter sheeds of less than say 1/750th by the time you've accounted for the digital crop factor and it's not surprising things haven't worked out as you expected.
Have a look on Andy Bright's digiscoping site, there's lots of advice regarding the use of teleconvertors on there.
Duncan.
Quote:
|
Originally Posted by Nogbad
Hi wondered if anyon can give me any tips. I was out yesterday trying to get some experience and photo's with the above lens. Went to Abberton to the back of the reservoir on the causeway. Good views of a Smew which was on the water. Tried various settings and then used the lens with a x2 teleconverter to give more magnifcation. I was using a bean bag and seemed to be getting some passable shots.
Once at home and downloaded obviously there was some camera shake, on some more than others. It isn't always practical to use a tripod and feel a bit
let down either with the lens or my own inability to get a decent shot.
I am hoping to buy the new Tamron 500mm zoom in a few months and dont want to feel I've wasted my money. Especially if I cant get some decent shots with the Sigma.
Any tips would be useful.
Nogbad
|