Just to drive the "optical purists" amongst us nutz ...
Just to drive the optical purists nutz ...
I took the AF 200mm f/2.8 APO G HS lens and mounted to the Kenko 300 3x T/C ... mounted it on the a850 and then place it in the APS-C capture mode ... effectively making it ...
well, let's do the math, boys and girls:
200mm x 3x (T/C) x 1.5 (APS-C crop factor) = 900mm! Oh yeah!
let's do the obligatory "light loss" calculation, too:
f/2.8 x -3f/stops = f/2.8 ... f/4 ... f/5.6 ... f/8
Hey, it still autofocuses! Hoohah! :eek:
Obviously, it is not where near as sharp as ... hey, wait a minute, no one has a 900mm lens for the SONY mount. Cripes, you might get it with a 2x T/C and a 300mm f/2.8 APO G SSM in APS-C mode. Let's check the cost of that ... oh yeah ... $6150, for the 300mm f/2.8 lens alone! Hmmm, guess we will all just run out and pop for one of those, huh?
Anyway ... for that long distance shot, you just cannot get closer to. Like Uncle Clyde coming down the slopes, in Vancouver, during the Olympics (2010). :p
The image is pretty cool.
I mean it is obviously not incredible zoom ... but the weight is incredibly light for it. The lens weight is 28 oz and the T/C is practically nothing @ 7 oz.
The thing is, with optically zooming the image ... you still have all those pixels to blow the bad boy up either further! And there he is ... Uncle Clyde, shooshing down the slopes.
Super long; Quality ... questionable
Well, to really give the optical purists a heart attack :eek:, there is the Rokinon 650-2600mm f8 to f-16.
Hey, there ain't nothin like carrying around a 4 inches in diameter x 18.5 inches long lens. ;) Ah, but with a 5-meter minimum focal distance, you don't have to worry about scaring away your subject. :rolleyes:
Stop the darkness, already!
The real need to do what I did was to have some control over just how dark this 'bad boy' gets. After f/8 ... the AF quits working properly in most DSLRs. Heck, usually after f/6.3.
I am pleasantly surprised the image turns out as well as it does ... and on the 200mm, it still is rather snappy.
I have never been really BIG on T/C use ... but SONY is not leaving the world much of a choice, when it comes to long glass, at the moment. SIGMA wants almost $8000 for their 800mm f/5.6 (Minolta-mount), which is 20.5" long, weighs 10.5 lbs and has a minimum focusing distance (M.F.D.) of 23-ft!
Well, I can just suffer with f/8, 34-oz and an M.F.D. of 7-feet. ... for that kind of coin. $10 a millimeter. Yeah, right!