As a quick trivia question, anyone know why every 1.4x teleconverter from every manufacturer results in a 1 stop loss of light and every 2.0x teleconverter results in a 2 stop loss of light?
I have used a 1.7x on my 70-200/2.8vr Nikon Lens. It makes it a 340mm f4.8 IIRC- Sharpness was fine but it did slow down the AF a bit.
Perfect--that's exactly the info I was looking for!
Thanks to you and everyone else.
follow up question...i was under the impression you should only use them over 100mm or risk damaging the lens or camera( been a while since i read that so as usually my brain is full of cotton) yes or no? wondering as would i have to remove one on my 70-200 if i went below 100? thinking "no" due to gdad's experience?
L-series lenses 135mm and up, as well as the EF 100-400mm f/4.5-5.6L IS USM, the EF 70-200mm f/2.8L IS USM, the EF 70-200mm f/2.8L USM,the EF 70-200mm f/4L IS USM, and the EF 70-200mm f/4L USM.
i use the tamron pro SP (the white ones which have more elements than the standard black tamron ones). they fit any lens as the don't have the protruding area.
Just another option for the OP - If you only need this for a specific situation, why not rent a 400mm lens? Unless you think you would use the teleconvertor frequently enough to warrant buying one. I've personally used several different online rental companies (I try before I buy and have no purchasing regrets ). I can list some links for you, if you're interested.