russbecker wrote in post #18308539
I have been comparing bird images posted on this thread taken with the 400DO II + 1.4x, i.e. effective focal length of 560mm at f/5.6, with pictures I have of the same species in similar light and similar ISOs taken with the Tamron 150-600 at f/6.3 and 500 to 600mm using a 7D2. I have to say I don't see a compelling reason to switch to this combo in that configuration from the Tamron.
I haven't seen many photos presented here where you would see much of a difference. Most of the images are downsampled, some quite a bit. Critical sharpness is most useful for heavy crops or very large prints (and upcoming large, hi-res monitors, when they have as many or more pixels than the cameras). I have the G1 Tamron, and while it is close to my 400/4 DO II IS stopped down a bit, the DO is much sharper wide open. The AF on the DO is also surer and faster; something you don't see in example photos, when you only see what the photographers think are worth posting after culling.
That said, I must admit that the inability to almost instantly back out to 150mm (or 100mm, as with the 100-400 I used to use) has cost me a lot of potential shots. I was standing on a dried lake bed in Florida last week, and seven Sandhill Cranes came down and landed 50 feet away from me, some flying straight toward me, and what would have been the best moments to photograph them, they were much larger than the frame. I even popped out the 1.4x as they were getting closer, but it did not help.
Heavy cropping from the DO has made me a fan of fast, sharp primes. Missed shots have caused me to be a little bit jealous of people who are not addicted to the critical sharpness with TCs and use the better quality 400mm, 500mm, and 600mm zooms as a sole lens in the field.
It seems to me the strong points of the 400DO II, other than weight, are using it either at 400mm and f/4 where you can gain an f-stop in low light situations (at the expense of having to get closer)
... and you *must* get closer to get the noise benefit; if you stay at the same distance, your only benefit is in AF ability. Cropping a lower-ISO version without the TC can have the same or even more noise when subject size is adjusted.
or using it with a 2X extender so you have 800mm at f/8. I would like to know how well the 2X extenders work with this lens and how hard that combo is to use, i.e. are you stuck using a tripod and can you actually use f/8?. Handholding at 600mm takes practice, even with IS.
I find little challenge in hand-holding the DO at 800mm with APS-C. I've taken sharp shots at 1/30, maybe 1 out of 3 with no noticeable blur in a slowly-shot (non-burst) series, when the subject was not moving around, and I was settled in and relaxed. Sometimes my coordination gets a little loose momentarily, and the single-point will drift off of a small bird barely larger than the AF point in the OVF, and I force a time-wasting AF on the background or some unintended branch, but everything works out most of the time, if the subject doesn't flee and you get more tries. The biggest problem with f/8, at least on the 7D2, is that when you miss the subject like that in AF, it takes too long to get back in focus, which happens much faster with 560mm/5.6. I thoroughly expect Canon to put much better f/8 AF into the successor to the 7D2; even just having the nine central AF points as f/8 would be a great improvement, as the nine-point AF mode is much less prone to hunting at f/5.6, when light and/or contrast are low.
My own personal Kingfisher!
