>> Right now the "digital lenses" on the market tend to be ultra-wides or >> wide-zooms, which are not easy to produce fast for any image circle. >> There's not much incentive for manufacturers to make, say, a 33/1.4 DA >> (especially if you are one of those companies that actually MADE a >> 35/1.4). Personally, I'd LOVE to see a 60/1.4 DA or 20/1.4 DA to get >> some of my favorite focal lengths back, but I don't think it's gonna >> happen. Most pros can apparently now work exclusively with f/2.8 >>lenses >> and get away with it, which means mostly zooms except at the extremes.
>And there are some lenses with image stabilisation in Canon and Nikon, >allowing you to shot at speeds up to three stops slower than normally and >achieve sharp pictures. If you have f2.8 zoom that would be as you had f1 >one in terms of possibility to shot without the risk of image shake... Assuming your SUBJECT is not moving. VR/IS only really counters CAMERA movement. Also, most if not all VR/IS lenses are tele zooms or ultra-tele primes. Yeah, you can hand-hold a wide a lot slower, but I can do things with my 28/1.4 that I cannot do with my 20/2.8 on a DSLR. >> Look at the olympus E-system. The lenses are digital only, and pretty >> fast. Of course the sensor is tiny. >That's not true. 4/3 sensor is almost as tall as APS sized one. It is >only >narrower due to aspect ratio (4:3). Last I looked, the crop factor was 2.0x. That's a small sensor. Sensor size doesn't matter, of course, assuming that sensor quality is OK and optics designed for the sensor are OK. I'm real leery, because most ultrawides wider than 20mm I've used are not great, whereas most ultra teles are quite good these days. This suggests that a bigger sensor tends to allow better (but bigger and more expensive) lenses. >> The only place I see pros using 1.4x converters on zooms is on the very >> highly evolved 70-200 ultrapro things from Nikon and Canon. Apparently >> the quality loss isn't unacceptable when using these very good >> teleconverters with what are arguably the best lenses N and C have ever >> produced. Oddly, I don't think either company makes a 100-300/4 >>EDIF-IS >> zoom. Sigma, of course, makes a 100-300/4. >I don't think there is any significiant loss of quality with not only >genuine 1.4x TCs, but even with cheaper constructions like Tamron 1.4x. >We have made some tests with Dario using SMC-F* 300/4.5 and this Tamron, > and the difference in sharpness between naked lens and coupled with >teleconverter was neglible. 2x TCs is another story though. With primes. Zooms don't normally handle even a 1.4x teleconverter well. I don't know about 3rd party teleconverters, but I know that the 1.4xS Pentax converter mated to the 300/2.8 A* was a noticeable loss in quality. Yes, it should have been a 1.4xL converter for best results, but that does prove that converter quality or design counts. It also seems to vary a lot on a lens-by-lens basis. The F* 300/4.5 is an exceptional lens. Most pros I know readily use a 1.4x TC with tele primes, sometimes even with 70-200 zooms. None I know use a 2x converter. Nikon has just put out a 1.7x that, if it actually works well, might intrigue me. I only USE one TC, the Nikon TC14B, and only with my 300/2.8 AIS. I own a 1.4xS pentax (works OK with the M150), a 2x Tokina (broken), and a 2x spiratone screwmount (basically untried). DJE
