Shutter speed 2x frame rate golden rule!

[John McCully]

Ron, I assume you are shooting HD with the AX100 in order to obtain 60p. I do recall your serious preference for higher frame rates. I too subscribe to the notion of faster-is-better frame rates and that's one of the reasons I imported an NTSC model AX100 maximum 4k frame rate of 30p vs. purchasing locally a (less expensive) PAL model maximum 4k frame rate 25p.

My next purchase might well be a Handycam that shoots 4k at 60p. That would be nice. While the popular 1 inch sensor as deployed in the AX100, and more and more cams as time passes, I suspect (shall we call it) the AX200 which delivers 4k at 60p is not just around the corner. I would be extremely happy to be wrong of course, but it seems that the smallish Handycam form factor, which I enjoy, presents serious challenges to the manufacturer not the least of which is heat dissipation. I would also like a brighter EVF than on the AX100.

Whatever, the 4k capable AX100 with the shutter speed flexibility, even at 30p, is certainly a hard act to follow. I'm not holding my breath waiting on 8k, HDR and who knows what higher frame rates :-)

[John McCully]

Thanks Dave, and yes, I certainly agree that the ND's are a convenient and efficient way of managing exposure. It was only the switching between photo and movie mode that got me checking out shutter speed effects, and the apparent lack thereof.

Yes, I am aware of the RX10 series. I have the original and before I acquired the AX100 it was my go to cam almost invariably. Now it sits forgotten somewhere or other. I too was somewhat surprised Sony did not include ND's on the RX10 III to the point that I decided against going with that model (one of the reasons). I presumed it was because of the already humongous lens on the cam and adding built in NDs would have been just over the top altogether.

Regarding the ND-less RX10 III perhaps, as with my experience with the AX100 that is the subject of this thread, high shutter speeds may not cause problems. Have you tried simply cranking up the shutter speed to reduce exposure in lieu of ND's? That might be interesting...

[Ron Evans]

John, I have had the FDR-AX1 since they came out and in good light it produces a nice image at 60P. I am going to look at the Panasonic AG-UX180 if/when it appears in the fall. That has a 1" sensor , shoots UHD 60P, 20x zoom and hopefully a nice match for the other cameras I have but will be a replacement for the FDR-AX1 and maybe even my NX5U. Probably has a Sony sensor !!! If Sony had put UHD 60P on the PXW-Z150 it would have been the camera to get. I am sure they could have and choose not to for some strange marketing reason !!! I am an all Sony guy at the moment but this fall may be the start of a change,


I too like the AX100 even though I shoot 1920x1080 60P exclusively on it.


Ron Evans

[Dave Blackhurst]

@Ron - the "HD" from the 1" class sensors is pretty good, but once I got the shutter speed tamed, 4K has been my preference (even if I wish it was 60P).


@John, I think it will be a while before we see 4K/60p, as it's really at the bleeding edge for the entire chain from acquisition to display. Maybe 3-5 years... probably more? And unless you're dealing with absolutely HUGE screens, these other higher resolutions are probably a bit of overkill (even well shot HD looks good on a 4K screen).

I've got the RX10 sitting around as well, I've been saving it for a couple still shooters I know that are
"thinking" about an upgrade, and it is a darn fine camera for stills and HD video, any way you slice it! Eventually, it may go to ebay...

i grabbed a "Mk2", and that's my main/secondary cam alongside the AX100 right now. The M3 is on my "hit list" once the prices drop a bit on a "lightly used" one.. I'll decide on the ND once I've used it a bit, I'd much prefer that it's in the body like on ALL the other RX's (10 and 100), but that new long lens means it will replace multiple lenses and an aging small chip superzoom, so once that stuff is sold off, I can afford a decent variable ND <wink>.

The M3 is expensive, bigger and heavier, but for me that lens is a huge attraction! iF I have to kluge the filter setup, so be it... the lens is a bit slower than the f2.8, and so maybe I can just stop down to slow the shutter speed.... I think the M2 will probably be sticking around as a backup anyway if I need the ND feature!


The Sony Cybershot team seems to be a bit more aggressive with product releases, even while retaining the basic design elements (for the most part). I'm on the MkIV of the RX100, they keep dribbling upgrades (sensor primarily, and at least a rudimentary 4K capability (due to the heat issues in a teeny, tiny body). The RX10M2 doesn't have heat issues, has the updated sensor, and was an easy choice... the M3 was a surprise, but makes sense to me. I'm intrigued to see what they might cook up next!

Logically, there SHOULD be a AX100M2 with the upgraded sensor, yet the Handycam division seems intent on pushing the small chip/BOSS format (now on it's second iteration). I fear that the AX100 may not EVER be dupiicated/updated (although I feel it is a "reincarnation" of the venerable HC1 in many ways). It would be a shame, but I'm OK with not feeling there is any compelling reason to "upgrade" the AX100 anytime soon!

I've wondered if at some point in time Sony will integrate or merge or whatever the "consumer" Cybershot and Handycam lines to improve efficiency - the low end video and P&S markets are "mostly dead", so pretty much anything underneath the "enthusiast" stuff is "dead money" for R&D or market share (a shrinking fraction of a vanishing market is NOT where Sony will put it's money). Since they just sold off Vegas, so restructuring wouldn't be a surprise...

[Ron Evans]

Originally Posted by Dave Blackhurst

@John, I think it will be a while before we see 4K/60p, as it's really at the bleeding edge for the entire chain from acquisition to display. Maybe 3-5 years... probably more? And unless you're dealing with absolutely HUGE screens, these other higher resolutions are probably a bit of overkill (even well shot HD looks good on a 4K screen).

...

Most of the 4K TV's in local stores are now 60P with HDMI 2.0. Panasonic this fall , if they are on schedule, will have the AG-UX180, what I had hoped the PXW-Z150 would be , 1" sensor, 20xzoom, UHD 60P to SDXC U3 cards with SDI and HDMI 2.0 for under $4000. Unless you are a real Sony fan or need streaming the PXW-Z150 will not be competitive. Probably uses a Sony sensor too. I use EDIUS 8.2 to edit that has no problems editing UHD. So I do not see the transition to be a long time away. I have had my FDR-AX1 that does UHD 60P for almost 3 years and yes that is sort of bleeding edge since it took a long set of updates to not quite finish the product. I think the real problem for 4K TV's is that SD input looks horrible so watching legacy stuff will be a bad experience !!!!

Ron Evans

[Bruce Dempsey]

sd looks just fine on a 4k screen provided the viewing window is sized in proper proportion

[Ron Evans]

Yes I understand, but what consumer is going to do that when playing an old SD DVD from their DVD player to a 4K TV ? And how many TV will allow you to just use a small portion of the screen to view in that way. Not done any research on that but have seen a simple playback of SD on a 4K TV and it is not good. The upscalling to UHD from SD is not good.

Ron Evans

[John McCully]

The Panasonic AG-UX180 looks rather much like it shall be my next cam acquisition from the little I know about it and assuming there are no devils in the details. Due October 2016 I understand. In the meantime the AX100 is doing the job quite adequately and for some situations will continue to enjoy a spot near the front of my gear bag.

But a 1 inch sensor, 4k 60p, not costing an arm and a leg, is where I want to be, ASAP.

[Rainer Listing]

Originally Posted by John McCully

Dave, using my AX100 under the conditions described above the rule is not just bendable; it is broken

Me again, still embarrassed from my earlier post, but I think this is significant. I always understood the "rule" wasn't related to any particular camera and had nothing to do with electronic technology - in any case a video camera is going to use less buffer at higher speeds. Its all about physiology - do we think footage looks better with motion blur? Another chink in the "rule" came with John's reference to gannets, which probably dive at 100mph and thus still should have motion blur at 1/200th. A while ago I was shooting next to a pro who was happily shooting 50i footage for TV of some boat races at 1/500th, unaware of any such rule. Anyway, I grabbed my nearest camera (a point and shoot PanyTZ70) and panned some veranda slats, handheld, but good potential for motion blur or stobing. I'm having difficulty seeing the difference between 1/50th and 1/250th, and maybe the 1/250th looks better. I've posted the footage on Vimeo.

Shutter Speed 2X framerate "rule" on Vimeo

I'll experiment further, but I'm inclined to agree - the "rule" is not just bendable, it's broken.

[Gary Huff]

Originally Posted by Bruce Dempsey

sd looks just fine on a 4k screen provided the viewing window is sized in proper proportion

SD doesn't even look good on a 1080p display of larger sizes (65"+).

[John McCully]

No worries, Rainer. While I discovered deviating from the old 2x frame rate for shutter speed guide/rule with my AX100 did not bring about the end of the world as we know it I would hesitate to elevate this finding to a new statement of fact applicable at all times and in all circumstances. I did choose my words carefully pointing out 'under the conditions of the experiment'.

Furthermore, I confess to having no idea what is going on under the hood (nor do I care that much actually).

Let me add a caution: I would not go so far as to suggest this approach as a general new rule. The take home I suggest is that if the cam one is shooting with does not have ND filters and you don't want to fiddle with screw-ons then try upping the shutter speed, even as high as a 4000th, to control exposure, thereby seriously deviating from the old guide/rule. But test before shooting something important, as you are doing :-)