Rolling Shutter VS FPS confusion

Started 3 months ago | Discussions
OP Currantos Senior Member • Posts: 1,291
Follow up

Yes, agree on those points and have kind of was going with that myself.

Could you explain how to mitigate mild shutter rolling shutter effects in post? I have never heard or seen anyone attempt to do that. So if I dancer's arm is bent due to rolling shutter I can unbend it? Same with other things? Sounds unreasonably complex and I won't ever be able to deliver more than 2 images that way when they expect hundreds to choose from.

Hmm, still no fool proof solution.

I will try electronic first curtain and report back

OP Currantos Senior Member • Posts: 1,291
Re: Rolling Shutter VS FPS confusion

Could you tell me about the pre-capture facility, I never heard of that and never heard of 50-60 fps, how is that activated and what cameras have it? Top FPS I heard is 20 from A9.

tony field Forum Pro • Posts: 10,904
Re: Rolling Shutter VS FPS confusion

Currantos wrote:

dancers need to be caught at the peak of the jump so high FPS is absolutely necessary, timing is very difficult. A microsecond before or after and they come out of a pose and both arms and legs are now "out of place" and scattered in space rather than "tucked in" so to speak. In dance there are tons and tons of "decisive moments' that often last less than a second easily, with smaller jumps and movements they can be just a flicker, not even a full "run jump suspend in air land" type sequence. Just a hop or skip out of nowhere can be all they give you.

I definitely missed tons and tons of shots and need faster shutter.

Hopefully will experiment one day and see, for now I don't have access to electronic shutter, just in the planning stages.

I find that surprising. I shoot ballet, modern, folk dancing as well as sports like show jumping speed skating using only single frame never motor Drive. I have no issue capturing Peak action. Shutter speed between 1/60 of a second and 1/250 sec are most useful and on rare occasions it is fun to shoot in very bright light at 1/400 of a second.

I have no issue with rolling shutterson my DSLR.

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OP Currantos Senior Member • Posts: 1,291
Settings and other

For the most part, I find myself light limited so compromises have to be made.

I prefer 1/400-1/1000, but will accept 1/250. Slower than that feet/hands start looking mushy.

I will be trying out the Z6 and hopefully it works?

One thing I am confused with about EFCS. If the sensor starts the exposure all over and then mechanical shutter terminates the exposure, wouldn't the far side of the sensor see light for longer since it takes time for the shutter to traverse? But then there are illustrations of the "reading row of pixels" running ahead of the edge of the shutter so maybe that is how it works. Then the problem is less I guess.

Ultimately, I don't have to fully understand something to be able to use it well, just practice and experience and advise from others that figured it out.

OP Currantos Senior Member • Posts: 1,291
Re: Rolling Shutter VS FPS confusion

Thank you for the response, I guess it is different for different people and I definitely am not good enough to catch peak action with single shots and have to use faster FPS to catch it. Perhaps with practice and time, for now it is "gun the shutter" approach that is needed for me.

I have not had luck with anything slower than 1/250, hands and feet will be blurry and slightly indistinct. At 1/125 there is enough blur to make the pictures a little nauseating in my opinion on jumps or turns and looks smudgy.

Some of it could be explained perhaps by distance? I have not seen your site, will look later. Shooting from far away is easier on the blurriness as the relative distance traveled by the object is smaller. Shooting up close is much tougher to catch sharp. So if the blur is 3 pixels with 300mm and 15 pixels with 50mm shots they will look very different.

sybersitizen Forum Pro • Posts: 18,047
Re: Follow up

Currantos wrote:

sybersitizen wrote:

If objectionable rolling shutter effects actually appear in some of the results, perhaps mild ones can be mitigated in PP.

Could you explain how to mitigate mild shutter rolling shutter effects in post? I have never heard or seen anyone attempt to do that. So if I dancer's arm is bent due to rolling shutter I can unbend it? Same with other things?

The feasibility of mitigating mild rolling shutter effects would depend on the specific effects that appear. Indeed, I might be able to unbend a dancer's arm if it's not too distorted, using manipulation tools in Photoshop. Same with other things. (I should make it clear that this requires some tools and skills that not all photographers have.)

Sounds unreasonably complex and I won't ever be able to deliver more than 2 images that way when they expect hundreds to choose from.

Probably true, but it might not be necessary to deliver more than two that way. My point is that if I had to use an electronic shutter to do the job and only a small percentage of shots showed anything objectionable, I could perhaps mitigate those effects in that small percentage.

Hmm, still no fool proof solution.

No, not foolproof.

I will try electronic first curtain and report back

With what camera? What sensor readout speed?

sybersitizen Forum Pro • Posts: 18,047
Re: Settings and other

Currantos wrote:

One thing I am confused with about EFCS. If the sensor starts the exposure all over

The sensor doesn't start the exposure all over. The pixel lines are activated sequentially, at the same speed the mechanical shutter will use when it closes.

and then mechanical shutter terminates the exposure, wouldn't the far side of the sensor see light for longer since it takes time for the shutter to traverse?

No, but there are in fact possible consequences of EFCS caused by the difference in the planes of the two shutters. In some cases the appearance of objects in a blurred background can be distorted. In other cases there can be uneven exposure across the frame. However, these things are only a concern at very high shutter speeds, say in excess of 1/2000s.

For your situation, I assume the major drawback of EFCS is that it's not silent, which will be an issue with every shot you take.

Chris R-UK Forum Pro • Posts: 20,854
Re: Rolling Shutter VS FPS confusion

Currantos wrote:

Could you tell me about the pre-capture facility, I never heard of that and never heard of 50-60 fps, how is that activated and what cameras have it? Top FPS I heard is 20 from A9.

20 fps is with continuous AF.  A lot of mirrorless cameras can shoot at 50-60 fps with AF and exposure locked on the first frame.  It is clearly only useful if you are able to shoot a burst without moving the focus.

Pre-capture is a variation on this and has been around for 15 years or more, but has made a comeback recently.  It is called different things on different cameras and is used extensively (without you knowing about it) on camera phones.  Typically, you set the fps rate that you want (which will mean fixed focus if you want over 20 fps) and the number of frames that you want to capture, say 25.  When you push and hold down the shutter half way, the camera starts capturing images.  When you push it the whole way down, it saves the last 25 images and continues shooting at 50 fps until the buffer is full.

I have only used it once, trying to get a killer whale breach, and took 600 frames in 4 minutes - without getting a breach shot!

The other way that you can shoot at high fps rates with a camera that supports 4K/60 fps video is to shoot video and extract the frames that you want.  4K gives you 8MP images.

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Charles2
Charles2 Veteran Member • Posts: 6,353
Re: Rolling Shutter VS FPS confusion

Some cameras have a quieter mechanical shutter than others.

Some cameras pull up shadows better than others, so short shutter speed and high ISO are not as much a problem. Skill at post-processing the raw file helps.

Search for ballet photos on Flickr. Many of the photos are identified by camera and exposure data.

tony field Forum Pro • Posts: 10,904
Re: Rolling Shutter VS FPS confusion

Currantos wrote:

Thank you for the response, I guess it is different for different people and I definitely am not good enough to catch peak action with single shots and have to use faster FPS to catch it. Perhaps with practice and time, for now it is "gun the shutter" approach that is needed for me.

I have not had luck with anything slower than 1/250, hands and feet will be blurry and slightly indistinct. At 1/125 there is enough blur to make the pictures a little nauseating in my opinion on jumps or turns and looks smudgy.

Some of it could be explained perhaps by distance? I have not seen your site, will look later. Shooting from far away is easier on the blurriness as the relative distance traveled by the object is smaller. Shooting up close is much tougher to catch sharp. So if the blur is 3 pixels with 300mm and 15 pixels with 50mm shots they will look very different.

I generally use shorter focal length. My web page is no longer functional however here are a few samples from my DPR gallery

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Charles Darwin: "ignorance more frequently begets confidence than does knowledge."
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KLO82 Senior Member • Posts: 1,421
Re: Rolling Shutter VS FPS confusion

Dem Bell wrote:

Are there many CMOS sensors that can do much better than 1/40 sec?

A9/A9II is 1/160 sec and 1DX3/ R6 is 1/60 sec.

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