Originally posted by jbrowning So what do you do when the Sigma 50-500mm lens just isn't log enough to get some shots of wildlife (tele-converter is not the answer, to me it makes the shot soft). I know that no matter what I do there will be something that this new lens or scope can't get either. So my options that is see right now is to sell this lens and get a longer lens or sell this lens and use the money to get a spotting scope and adapter for my K20D.
So my question are what would a scope give/not give me that a reg camera lens will give me?
Jim, first I would heartily second your notion, not to use a tc with the Bigma. It simply gets too slow to work with a tc - and that is even not taking IQ into account.
There are several options you can choose:
- use a spotting scope with provisions to attch a camera. Pentax makes nice Apo scopes, but there are countless others out there. The real drawback of this option is, that they do not have an diaphragm. So you can't close an aperture to increase the tiny DOF or in really brigh conditions. That should be taken into consideration.
- you could still buy the FA 600/4 from Pentax Japan new. Something like the most expensive solution, I guess.
- you can buy an old Pentax 500/4.5 and add the Pentax 1.7 AF-converter, to have AF under brighter conditions or simply a Pentax 1.4x-L converter, if you don't need AF. This lens produces some CA and is slowlyer to use than the Bigma, but still a very good choice in terms of bang for the bucks.
The real drawback is, that it is very hard to get really sharp shots under the conditions, you present in your photos here, as over longer distances, the atmospheric turbulences ruin most shots. You need even more patience, than with the Bigma and very short exposure times, to "freeze" the turbulences.
Ben