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05-05-2014, 02:38 AM   #121
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QuoteOriginally posted by DSims Quote
You won't be able to demonstrate that a photo of a runner or soccer player in full motion at 1/160 or 1/180s will ever freeze the motion as well as 1/800 or 1/1250s. You won't be able to produce the photos to prove it. But go ahead and try - we're all waiting to see the example photos!

So you can give all kinds of great technical explanations, but it won't work because you're leaving something critical out of your theory.


And my rather weird, example "translation" was simply to say that you are stating some small truth that doesn't really count for much when viewed in perspective, compared to the whole picture.

In case you were wondering, I've never tried that before either (that is, getting into an accident while picking my nose)!




This is terrible advice for a beginner. While it's conceivable there's some small advantage to using 1/180s compared to 1/250s on a Pentax, it will never freeze fast motion going in a different direction than you're panning the camera (if you're even doing that), so you have to stick to the standard rules of about 1/640 to 1/1600s minimum shutter speed if you want to freeze all the action in the frame.
"So you can give all kinds of great technical explanations, but it won't work because you're leaving something critical out of your theory."

i'll be the first to accept this, but it would be interesting to know what it is i'm leaving out

the theory here is indeed a bit non-intuitive, and it might not apply to many situations (like movement which is "composed", as i noted, not predominantly in one direction -- like the hokey examples). most of my experience with action shooting is rally (which is very different form hokey or runners etc), i agree without a test the "theory" is questionable.

to be fair, the discussion should have been started separately, not in a beignner thread, you've got a point there, i can see how it can only be confusing to a beginner. my bad there.

note: i never said "don't use anything above 1/180" i just said "don't expect anything above 1/180 to do miracles", that's all.

i'd say let's park this, or maybe move it to a different thread, so as not to hijak our new members thread (again, my bad there, apologies to the original poster)

05-05-2014, 05:39 AM   #122
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Perhaps you are misread in your line of thinking, it appears this applies to video not stills;

"Rolling Shutter is the way that most DSLR are shooting video. (and point and shoots and iPhones too). For 95% of the time it does not really matter what type of shutter is used for capturing video, in the other 5% it matters a lot. Following is a break down and explanation of what is Rolling Shutter why it is being used and what are its quarks"

WHY IT MATTERS?

Generally speaking, CCD sensors utilize a Total Shutter and CMOS sensors utilize Rolling Shutter. While there are many reasons for camera manufacturers to choose one type of sensor over the other – processing speed, power consumption, cost, complexity and more, CMOS sensors (which use the rolling shutter method) tend to deliver the image faster, thus clearing the sensor for the next shot.

This may not be an issue with stills, but is a huge factor when selecting a sensor type for video – the sensors needs to take 24,30 or 60 frames a second. This is why almost all our DSLR and Smartphones sensors are using rolling shutters.

Oddly enough, this is also when we can most noticeably see the effect of Rolling Shutter. Especially with fast moving or vibrating objects.


http://www.diyphotography.net/everything-you-wanted-to-know-about-rolling-shutter/

From your link:

Rolling shutter
From Wikipedia, the free encyclopedia

Rolling shutter is a method of image acquisition in which a picture or each frame of a video is recorded not from a snapshot of a single point in time

Last edited by Oldbayrunner; 05-05-2014 at 06:23 AM.
05-05-2014, 10:07 AM   #123
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the term "rolling shutter" has been made famous by the emergence of consumer video devices, but in general the term rolling shutter applies to all such shutters (where portions of the frame are exposed at different times, as opposed to a global shutter). anyway, the topic is a bit tricky and apparently people find their rolling 1/4000 very dear to their hearts, so let's let it rest or move it to another thread if somebody is still interested. in short, a rolling shutter works fine for "mostly static" subjects, or for freezing "local motion" within the frame (think of turning wheels on a fast moving car), it's not so good at freezing motion of the subject across the frame. Let's leave it at that.
05-05-2014, 11:03 AM   #124
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QuoteOriginally posted by Zealex Quote
Would that knock of AA battery holder be safe for use with my K-R? I have tons of AA batteries, but I'm not looking to drop 40 bucks on the original pentax one...
I bought the knock-off for my brother's K-r. Eventually I got him a second one. He thought the lithium battery wasn't as convenient. With two AA holders, he can swap them quickly for longer shoots.

05-05-2014, 11:11 AM   #125
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QuoteOriginally posted by Just1MoreDave Quote
I bought the knock-off for my brother's K-r. Eventually I got him a second one. He thought the lithium battery wasn't as convenient. With two AA holders, he can swap them quickly for longer shoots.
I'm going to order it once I'm home. I literally have an endless supply or rechargeable batteries... I could shoot for days, heck, weeks before running out of juice.
05-05-2014, 12:58 PM   #126
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QuoteOriginally posted by nanok Quote

i'd say let's park this, or maybe move it to a different thread, so as not to hijak our new members thread (again, my bad there, apologies to the original poster)
I think new members and old ones alike need to know this 'you get no improvement of freezing motion beyond 1/180' is a furphy, Nanok.

Perhaps a spinning aircraft propellor, but not one of your rally cars or basketballers sprinting across the court.

They will see more sharpness, not less, going from 1/180s to 1/1000.

Last edited by clackers; 05-05-2014 at 01:05 PM.
05-05-2014, 11:02 PM   #127
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i think old members and new ones alike need to make sure before making definitive statements. i already explained it's a bit more complicated than your simplified version above, even from the first post. you're trying to disprove something that was never stated, and with all due respect you don't have the data to go after it (and neither have i, as i already stated). read my last statement and think again

i would gladly do some testing, just for fun, (and i'm sure i'll find the results interesting even for myself), but i just didn't have the time. if you think no testing is needed, and that your "1/4000 is 1/4000 and the fact it's a rolling shutter makes no difference" is all there is to it, well..

happy shooting
05-05-2014, 11:31 PM   #128
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QuoteOriginally posted by nanok Quote
i think old members and new ones alike need to make sure before making definitive statements. i already explained it's a bit more complicated than your simplified version above, even from the first post. you're trying to disprove something that was never stated, and with all due respect you don't have the data to go after it (and neither have i, as i already stated). read my last statement and think again

i would gladly do some testing, just for fun, (and i'm sure i'll find the results interesting even for myself), but i just didn't have the time. if you think no testing is needed, and that your "1/4000 is 1/4000 and the fact it's a rolling shutter makes no difference" is all there is to it, well..

happy shooting
I would have said this was a cop out, until I saw this:

---------- Post added 05-05-14 at 11:47 PM ----------

QuoteOriginally posted by nanok Quote
the theory here is indeed a bit non-intuitive, and it might not apply to many situations (like movement which is "composed", as i noted, not predominantly in one direction -- like the hokey examples). most of my experience with action shooting is rally (which is very different form hokey or runners etc), i agree without a test the "theory" is questionable.

to be fair, the discussion should have been started separately, not in a beignner thread, you've got a point there, i can see how it can only be confusing to a beginner. my bad there.

note: i never said "don't use anything above 1/180" i just said "don't expect anything above 1/180 to do miracles", that's all.

i'd say let's park this, or maybe move it to a different thread, so as not to hijak our new members thread (again, my bad there, apologies to the original poster)
Thanks for your comment about it being a bit much in a beginners thread. I've now become a part of this too.

I think this is a shutter speed which probably works very well when panning with rally shots, and you may have (unfortunately) tried to apply it to action situations where the disadvantages of 1/180s would far outweigh the advantages. But your statement is interesting to me, and I can see how it might actually give better results than a slightly faster shutter, if you're going to be shooting around this fairly slow (for action) shutter speed anyway.


Last edited by DSims; 05-05-2014 at 11:49 PM.
05-06-2014, 03:23 AM   #129
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QuoteOriginally posted by nanok Quote
you're trying to disprove something that was never stated

Nanok, you seem to have forgotten what you stated, so let's have a refresher: "the highest useful shutter speed is really the sync speed (modern dslrs means somewhere between 1/160 and 1/250, pentax is 1/180 i think), making it faster than that will help little if at all."


QuoteOriginally posted by nanok Quote
and with all due respect you don't have the data to go after it (and neither have i

You can't possibly think our positions are equivalent!


You have the rules of evidence wrong.


The rest of the world doesn't need to confirm conventional wisdom, it's up to you to disprove it.

QuoteOriginally posted by nanok Quote
i would gladly do some testing

Glad to hear you're motivated, Nanok.


You could start in the K5 Sports Photography thread, and please identify which of the members' wastefully brief shots you think display distortion, blurring or missing parts of an object due to the rolling shutter effect. ;-)
05-06-2014, 05:35 AM   #130
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QuoteOriginally posted by nanok Quote
the term "rolling shutter" has been made famous by the emergence of consumer video devices, but in general the term rolling shutter applies to all such shutters (where portions of the frame are exposed at different times, as opposed to a global shutter). anyway, the topic is a bit tricky and apparently people find their rolling 1/4000 very dear to their hearts, so let's let it rest or move it to another thread if somebody is still interested. in short, a rolling shutter works fine for "mostly static" subjects, or for freezing "local motion" within the frame (think of turning wheels on a fast moving car), it's not so good at freezing motion of the subject across the frame. Let's leave it at that.
Now that you have hijacked this thread let's note a few things. #1 Most all cmos sensors use Rolling Shutter, which is not completely a bad thing . #2 What you really mean to be talking about is the Rolling Shutter Effects (artifacts); wobble, shew, smear or partial exposure which are more likely to occur when shooting video and in only in extremely isolated situations shooting still. #3 Can one duplicate it to prove a point it can happen, yep by shooting while rapidly wildly moving ones camera around hand held, shooting a propeller while in a fast moving plane, shooting from an unstable platform from inside a car, fast unstable movement while using an extreme telephoto lens or shooting at a faster sync rate than a flash allows.

For every 1 still photo taken under normal circumstances you could show having any of the artifacts thousands taken at a fast shutter speed would prove it as isolated.

For the newbies;


Last edited by Oldbayrunner; 05-06-2014 at 05:47 AM.
05-06-2014, 10:34 AM   #131
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QuoteOriginally posted by DSims Quote
I would have said this was a cop out, until I saw this:

---------- Post added 05-05-14 at 11:47 PM ----------



Thanks for your comment about it being a bit much in a beginners thread. I've now become a part of this too.
well, yes, in calling me out that i'm doing this in the wrong place, so i guess you're safe :P

QuoteQuote:
I think this is a shutter speed which probably works very well when panning with rally shots, and you may have (unfortunately) tried to apply it to action situations where the disadvantages of 1/180s would far outweigh the advantages. But your statement is interesting to me, and I can see how it might actually give better results than a slightly faster shutter, if you're going to be shooting around this fairly slow (for action) shutter speed anyway.
mhh, note really. in fact slightly faster works fine when panning, and even much faster works fine (though the "farther from sync you go" the more problematic it gets, panning aside), the only problem is that it will not fix your panning technique magically, basically what happens is if you're able to pan "well enough" for the sync speed, you'll be good, if not, increasing the shutter speed will prove frustratingly ineffective (not useless, iirc, but not even close in effect to what you'd expect); the picture will not look the same (many other things will look different), but neither will the faster shutter "fix what you want fixed", at least that was my experience (not scientific testing though, and other things come into play too, like focus, etc, so obligatory grain of salt etc)

i didn't mean to speak about panning exclusively anyway, but i admit i almost never shoot fast moving subjects from a tripod with high shutter speeds, so some sort of tracking is included in almost any action shooting i personally have experience with.

do you think the discussion is interesting enough still to move to a separate thread? i'm still curious what controlled testing will show, but i'm definitely not about to continue this here. beginner thread or not, this is clearly offtopic for this thread.

---------- Post added 05-06-2014 at 07:40 PM ----------

QuoteOriginally posted by clackers Quote
Nanok, you seem to have forgotten what you stated, so let's have a refresher: "the highest useful shutter speed is really the sync speed (modern dslrs means somewhere between 1/160 and 1/250, pentax is 1/180 i think), making it faster than that will help little if at all."





You can't possibly think our positions are equivalent!


You have the rules of evidence wrong.


The rest of the world doesn't need to confirm conventional wisdom, it's up to you to disprove it.




Glad to hear you're motivated, Nanok.


You could start in the K5 Sports Photography thread, and please identify which of the members' wastefully brief shots you think display distortion, blurring or missing parts of an object due to the rolling shutter effect. ;-)
Clackers, you seem to be unable or unwilling to read whole phrases.

please, let's continue this in a separate thread in the tech discussion section, or drop it, i think we've done plenty enough damage here already (and yes, i started it, my bad).
05-06-2014, 01:13 PM - 1 Like   #132
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QuoteOriginally posted by nanok Quote
do you think the discussion is interesting enough still to move to a separate thread? i'm still curious what controlled testing will show, but i'm definitely not about to continue this here. beginner thread or not, this is clearly offtopic for this thread.
I think it's at least interesting enough for some test shots. I don't see the point of "internet-arguing" in a beginner's thread, but if everyone can learn something, that's relevant.

You don't really lay out your theory in one post. It is apparently based on this: The shutter has two parts called the front and rear curtains. When you take a shot, the rear curtain starts out fully open, the front fully closed. The front curtain opens, the sensor is exposed to light, the rear curtain closes. The curtains are mechanical so they can only move so fast, and it is often useful to have a fast shutter speed. So when you want speeds faster than 1/180 sec., the rear curtain starts to close while the front curtain is still opening. In other words, at 1/180 sec. or less, the sensor at some point is completely exposed to light. At faster speeds, it is only partly exposed, by a traveling slit, the gap between the front and rear curtains. To get really fast shutter speeds, the rear curtain just gets very close to the front one. A mechanical trick.

It sounds like you think this has some effect on shots and everyone else doesn't.

I decided a ceiling fan was a good test subject. I put my camera on a tripod, put on a Pentax-F 50mm f1.7, focused in the center of the frame, in Tv mode. Some test shots showed I could use ISO 3200 for a useful range of shutter speeds. I took shots at 1/3000, f2.0, then pressed the AE-L button to keep that exposure. Then I stopped down a full stop in shutter speed, took a shot, etc. So my shots were:
1/3000, f2.0
1/1500, f2.8
1/750, f4
1/350, f5.6
1/180, f8
1/90, f11
1/45, f16
1/20, f22

Here is the first shot 1/3000:


IMGT5727
by just1moredave, on Flickr

And here is the shot at 1/180:


IMGT5731
by just1moredave, on Flickr

I have to say, all these shots look exactly as I would expect. The fan blades have more motion blur as shutter speed decreases, perfectly consistent with the shutter speed changes. With five blades, you can find one moving pretty close to parallel with that travelling opening. There's no panning and the blade speed is the same. So it's a decent test.

Unfortunately the fan is white, the ceiling is white, so the contrast isn't great. I raised it some in Lightroom, both shots the same. Also the fan wobbles slightly, and in Tv mode/fixed ISO obviously the aperture will vary, so DOF changes. I think this is visible in the first shot. I haven't thought of a better test and I'm not painting the ceiling black. Anyone else have a ceiling fan?
05-06-2014, 04:31 PM   #133
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Well, Dave, of course your shots show 1/3000 is much better than 1/180. Hats off to ya.


But you didn't need to defend common sense against a wacky theory (one that's just as misleading in a technical thread as a beginners, IMHO) - you could have better spent the time watching Game of Thrones or something . :-D
05-06-2014, 07:07 PM   #134
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QuoteOriginally posted by nanok Quote
do you think the discussion is interesting enough still to move to a separate thread? i'm still curious what controlled testing will show, but i'm definitely not about to continue this here. beginner thread or not, this is clearly offtopic for this thread.


please, let's continue this in a separate thread in the tech discussion section, or drop it, i think we've done plenty enough damage here already (and yes, i started it, my bad).
If you have some examples to show, then please start the thread.
05-15-2014, 09:41 AM   #135
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Hey I got a stupid question...

I'm thinking of getting a Class ten 64gb 90mb/s PNY SD card because it's on a killer steal deal at the moment. Don't really need that speed/memory but it has good reviews and is the same price of two class 10 16gb Sandisk SD cards at 30mb/s.

My question is do cameras have a limit on how much memory they can read and would the PNY work? I have the latest firmware for my K-r. I didn't find anything in my manual and googled it and only found that Kingston SD cards gave Pentax issues.

Thanks for reading.
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