Canon, King in SLR Cameras, Makes Inroads Into Mirrorless

ritholtz

EOS 7D MK II
Mar 25, 2014
584
12
C-A430 said:
ritholtz said:
Talys said:
ritholtz said:
Video seems to be good until they start moving camera. I think 1 to 1 pixel crop for 4k produces good quality for the targeted users. But no dpaf is a downer. I wish, they will solve one of this problem (crop or dpaf) at least instead of punishing users twice.
I agree that no DPAF is a downer. But this is a $740 camera. I think it's fine in that context, because you must expect to bump into some limitations at that price.

I would say the two downers are no Eye AF in AI Servo mode (I think) and no DPAF in 4k video mode.

But both would be good incentives to buy the next version up. Also, something to let Sony come in with a competitor at that price point -- as a6300/a6500 are much more expensive. And well, Nikon needs to get their act together for live view AF before they're part of that discussion.
For me only thing missing is DPAF. I can live with the 4k crop. I have used crop (digital zoom) feature with my SL2. It gave me reach to shoot some stage play. Unfortunately there is no dpaf when this functionality used with SL2 as well.
Why is no DPAF an issue? M50 is using phase detection AF in 4K, just as α6500. In 1080p it has DPAF, something no one has matched yet.

Sony and Panasonic NEVER use DPAF. Am I missing something?
I think, it is using contrast detection AF. It is early form of focusing with live view and slow. My t3i was like that. It has bunch of modes to help (using OVF phase detect AF) with live view. Pany and Nikon uses same contrast detection AF. It improved a lot over the time. Based on your experience, looks like Canon also doing fine with contrast detect AF with 4k.
 

3kramd5

EOS 5D MK IV
Mar 2, 2012
3,084
405
C-A430 said:
ritholtz said:
Talys said:
ritholtz said:
Video seems to be good until they start moving camera. I think 1 to 1 pixel crop for 4k produces good quality for the targeted users. But no dpaf is a downer. I wish, they will solve one of this problem (crop or dpaf) at least instead of punishing users twice.
I agree that no DPAF is a downer. But this is a $740 camera. I think it's fine in that context, because you must expect to bump into some limitations at that price.

I would say the two downers are no Eye AF in AI Servo mode (I think) and no DPAF in 4k video mode.

But both would be good incentives to buy the next version up. Also, something to let Sony come in with a competitor at that price point -- as a6300/a6500 are much more expensive. And well, Nikon needs to get their act together for live view AF before they're part of that discussion.
For me only thing missing is DPAF. I can live with the 4k crop. I have used crop (digital zoom) feature with my SL2. It gave me reach to shoot some stage play. Unfortunately there is no dpaf when this functionality used with SL2 as well.
Why is no DPAF an issue? M50 is using phase detection AF in 4K, just as α6500. In 1080p it has DPAF, something no one has matched yet.

Sony and Panasonic NEVER use DPAF. Am I missing something?


Sony’s latest OSPDAF methodology is somewhere between masked pixels and split pixels. Theoretically it might improve well capacity relative to both of those technologies. There is some indication it is being used in cameras like a7iii.

http://www.techinsights.com/about-techinsights/overview/blog/survey-of-enabling-technologies-in-successful-consumer-digital-imaging-products/ said:
Dual PDAF

It is a reasonable assumption that both masked PDAF and dual-PD-based systems could exhibit degraded performance in low-light conditions. In the case of masked PDAF, the lower fill factor of partially-masked apertures results in photon loss, as compared to a non-masked neighbor. In the case of dual PD, the twin PDs would require isolation from one another and the surrounding structures. The additional isolation results in an overall reduced full well capacity, as compared to a single PD implemented in the same pixel size.

Recent back-illuminated Sony chips have been found to use a new type of PDAF system that could be described as lossless. The 1.0 µm pixel generation Exmor RS chip in the Apple iPhone 7 Plus used a 1x2 microlens structure over two of eight pixel pairs in selected green-blue rows [16]. The wide microlenses cover a green filter in the Bayer pattern and a green replacement filter in the neighboring blue position. Two of 64 pixels in an 8x8 block use this lens structure and these blocks are distributed across ~95% of the active pixel array. A similar implementation of 1x2 microlenses were found in use in the Sony IMX398 from the Oppo R9s and have been dubbed “Dual PDAF”.
Found via https://www.dpreview.com/forums/post/60859607, where there is some fascinating analysis and discussion.