Converter question

[kevfreeflight]

Hi again - Its me again, the thick pilot here!! two questions in a day either means I am keen or as the case is - genuinely thick!

I have on the DSLR A100 Sony at the moment - the 75-300mm lens and love it to bits. Taken some stunning images with it (as long as its on Auto - then I have been happy - but now am wanting to expand my horizons - as per my prev email on shutters), however, been advised to look at a longer lens for taking photos of birds. I cant, at the moment, afford four to five hundred quid for a lens up to 500mm, however, have seen a couple of 2 x converters that would fit my camera.
Question, given that a converter would take my 75-300 to 150 - 600mm, am I going to lose anything on this and what advice would you give if I went down this road? Is it something worth considering?
I tend to photo airplanes and now getting in to wildlife etc. I have photos printed in a gliding magazine regular - but now I want to take better images and improve what I am doing.
Would be grateful if you could advise and make it in a language for dummies please for me.
Aircraft are easy to fly, cameras are incredibly hard!!
Many thanks

Kev

 

[troutfisher]

I dont know anything about sony cameras so please bear with me.
A 2* teleconverter will cost you 2 stops so if your lens is f5.6 at 300mm it becomes f8 with a 1.4 tc and f11 with a 2*tc.I dont know if your camera will autofocus at those apertures, if it wont you will have to manual focus and the image quality will suffer anyway with a tc ( depends to a large degree on the lens)
It might be cheaper to try and find a used tele,like a sigma 50-500 which certainly for canon cameras are not overly expensive used.

 

[ipswichboy]

If you go for a teleconverter I would stick to 1.4x rather than 2x. I found that the image quality suffered with the latter.
If you're looking at shooting birds in the wild you'll probably need somewhere around 500mm and if you want to shoot in all conditions you'll need something that can cope with the light (f/2.8 or f/4) and has quick autofocus. Most wildlife photographers I know have a large wallet to go with their large lenses.

 

[tdodd]

Not only will AF performance suffer, or cease completely, but would you want to hand hold a 600mm f/11 lens? You'll probably struggle to achieve adequate shutter speeds without taking the ISO very high to do so. You might find yourself restricted to tripod use only. I suspect you'll find IQ to be a disappointment.

If your lens is sharp, wide open at 300mm, then a 1.4X might be worth a punt, but I think a 2X would be taking things too far. Even with a 1.4X you may find that "action" photography is no longer an option.

TCs usually work best with fast prime lenses or very high quality zooms. Coupled to a consumer grade zoom lens, with a slow max aperture and perhaps good rather than excellent optics, I'd be hesitant to take the TC path. I'd suggest borrowing one if you can or buying from a source with a good returns policy.