[BruceBanner]

I was just reading the review about the K-1 and its Burst rate under different conditions;

Pentax K-1 Review - Performance and Burst Mode | PentaxForums.com Reviews

I'm in Jpg mode, but in a very dark room, I'm getting only about 30 shots off before fps drops compared to the review stating I should be getting 70-90 (depending on writing to one or both cards). It does state the test was done outdoors in bright conditions so I'm guessing the environment does make a big difference? I was shooting 1/250 ISO 800, as I said though only getting around 25-30 shots before fps drops. No Corrections on.

I was also curious about these following brain farts ;

- Does changing the size of the Jpg make a difference to the burst rate? Changing from L(36mp) and *** down to M(22mp) but still ***?

- Does applying the 1:1 Mode instead of FF or Crop increase burst rate or help the buffer out additionally? I know that the 1:1 in RAW mode is kinda 'fake', using certain RAW Developers you can claw back the crop, but with Jpg it would be baked in? Would it not behave like Crop mode and lead to faster fps and better buffer?


Cheers!

BB

[Ivan]

What kind of memory card do you use? Everything that loads the processor slows down the series. Even the noise suppressor. You need to completely repeat the test conditions. And then draw conclusions.

[BruceBanner]

What kind of memory card do you use? Everything that loads the processor slows down the series. Even the noise suppressor. You need to completely repeat the test conditions. And then draw conclusions.

Extreme Pro 95mb/s Sandisk or higher.

I haven't really tested anything at this time than just that, I was just amazed to getting only about half of what the article managed to achieve with a scene that was metering at -1ev with 1/250 with an ISO at 800. All lens correction was off, noise etc.

I'll retest in brighter conditions, I just had no idea that the conditions in which you shoot in dictate so wildly the results. I thought the buffer limit would not alter that much it would be just a case of having garbage images

[stevebrot]

I'll retest in brighter conditions

Retest in M mode so that you have unambigous control over shutter speed and aperture. Turn off AF and SR as well as all JPEG processing options. Use shutter speed of at least the X-sync speed.* Choose maximum aperture, otherwise the time for actuation (down/up) will slow things down. Don't use aperture ring, otherwise the time for actuation will be maximized. Use well-lit blank wall or open sky for subject.


Steve

* There may be some benefit to using near max shutter speed, depending on shutter.

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Last edited by stevebrot; 02-05-2020 at 01:58 PM.

[DeadJohn]

I was shooting 1/250 ISO 800

The added noise at higher ISO might increase the JPG size, because noise can look like fake detail that can't be compressed as much. As an exercise, take a picture of something like a black t-shirt (noise is more visible on dark objects) at extremes of 100 ISO and 6400 ISO to see how file sizes differ.

Does changing the size of the Jpg make a difference to the burst rate? Changing from L(36mp) and *** down to M(22mp) but still ***?

Lower resolution uses less memory, so can be written to the card in less time.

Does applying the 1:1 Mode instead of FF or Crop increase burst rate or help the buffer out additionally?

1:1 mp count and file size is smaller than FF, larger than crop.

[stevebrot]

The added noise at higher ISO might increase the JPG size

I have done comparisons at base ISO vs higher and this rings true, though I am not sure where the actual time lag factors in.

Lower resolution uses less memory, so can be written to the card in less time.

I tested this on my K-3 and found the opposite to be true on that camera for both smaller size and lower quality. The bottleneck is only partially in the data bus.


Steve

[Ivan]

It remains to conduct the series in jpg, on the basic ISO, with a disconnected correction. But it seems to me that there will be no success. It's too big a difference. If a series of frames is important to you, there's a reason to contact the service or let them show you how to set up your camera.

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Last edited by Ivan; 02-07-2020 at 03:24 AM.

[BruceBanner]

Retest in M mode so that you have unambigous control over shutter speed and aperture. Turn off AF and SR as well as all JPEG processing options. Use shutter speed of at least the X-sync speed.* Choose maximum aperture, otherwise the time for actuation (down/up) will slow things down. Don't use aperture ring, otherwise the time for actuation will be maximized. Use well-lit blank wall or open sky for subject.


Steve

* There may be some benefit to using near max shutter speed, depending on shutter.

My test was done (fwiw), Av mode with fixed ISO (800), aperture f2 or so, AF off, spot metering aimed at a bright monitor in a dark room, this gave 1/250. No fluctuation in shutter speed whatsoever throughout all the 30 odd shots (which is what I counted before running into a drop of fps).

I will test tomorrow as I have the day off, hopefully somewhere brighter to allow a good 1/2000 and base ISO etc. I will turn off SR as well as you suggest.

Jpg Correction stuff then.. I think I was in Natural for the Image Mode, no tweaking of it, and all other image processing off (no Clarity or any of that stuff). I'm just curious now as to what contributes Jpg Processing. Highlight Correction and Shadow Correction?

The added noise at higher ISO might increase the JPG size, because noise can look like fake detail that can't be compressed as much. As an exercise, take a picture of something like a black t-shirt (noise is more visible on dark objects) at extremes of 100 ISO and 6400 ISO to see how file sizes differ.



Lower resolution uses less memory, so can be written to the card in less time.



1:1 mp count and file size is smaller than FF, larger than crop.

I only mention this as it would appear to be true on paper, but for example using 1:1 in RAW mode makes no difference whatsoever because its still actually capturing data in the cropped parts. I wondered if this was true for the 1:1 in Jpg mode as well or if it behaves differently. We already know that Crop mode is actually a proper crop (no regaining the crop from a RAW file in that ratio) but I was curious about the 1:1

I have done comparisons at base ISO vs higher and this rings true, though I am not sure where the actual time lag factors in.



I tested this on my K-3 and found the opposite to be true on that camera for both smaller size and lower quality. The bottleneck is only partially in the data bus.


Steve

So are you saying using M or S rather than L or less *'s would actually result in a slower performance than just using native L with ***? See I could believe that to be true, somethings are faster in their native than having to 'think' and produce something other than default/native. My brief test between using M and L seemed to be the same amount of shots but again these were not great conditions.

So about file sizes, in general then, are well light bright sunny day shots smaller sized than darker shots? It does sound in theory that smaller file sizes - higher fps and better buffer capability as well as recovery, but I dunno... maybe it all just averages out due to computational effort?

It remains to conduct a series in jpg, on the basic ISO, with correction disabled. But it seems to me that there will be no success. Too much difference. If a series of frames is important to you, there is a reason to contact the service, or let them show how to configure the camera.

Ok... not sure of what you're saying here at all...

[Ivan]

I do not question your professionalism. I am a random person on the Pentax forum. But one of my cameras is an old K7 which I like. He does not make more than three ravas in the series. Not under any conditions .... With K1 I would go to service. It costs money and should work.Yes, and I'm Russian, I use Google translator. Excuse me.

[sbh]

- Does changing the size of the Jpg make a difference to the burst rate? Changing from L(36mp) and *** down to M(22mp) but still ***?

Shooting in jpeg only:

JPEG L * * * => 29 shots
JPEG XS * * * => 31 shots
JPEG XS * => 31 shots
JPEG L * => 41 shots

- Does applying the 1:1 Mode instead of FF or Crop increase burst rate or help the buffer out additionally? I know that the 1:1 in RAW mode is kinda 'fake', using certain RAW Developers you can claw back the crop, but with Jpg it would be baked in? Would it not behave like Crop mode and lead to faster fps and better buffer?

No. 14 shots until slowdown for both on my K-1. But cropping to APSC speeds up the framerate and goes up to 52 shots until slowdown.


I did some quick testing in FF mode. In RAW, the buffer can only take a certain amount of data until it's full. For example: I can take 13 shots at 1/250 or 23 shots at 1/8 until the frame rate drops. However, the 13 shots at 1/250 take 3 seconds and the 23 shots at 1/8 take over 6 seconds. Both equal roughly 4 frames per second.

In JPEG I get 45 frames at 1/1000 until the frame rate slows down and seemingly endless shots at 1/250 and 1/30 (I stopped at around 350 frames).

Turning on lens corrections (fat fifty) slows down the frame rate to approx. 1 fps starting with the first frame.

[stevebrot]

Yes, and I'm Russian, I use Google translator. Excuse me.

You are in good company. Many of our users are not native English speakers and many use a translation service when posting here. @Brucebanner was just saying that the translation was not very good. I was also a little confused until I saw you are in Riga and might be a Russian or Latvian speaker. Our conversations here are generally pretty friendly and not as rough as some of the eastern Europe forums.

I can only guess how this comment translates back into Russian!


Steve

[BruceBanner]

Shooting in jpeg only:

JPEG L * * * => 29 shots
JPEG XS * * * => 31 shots
JPEG XS * => 31 shots
JPEG L * => 41 shots




No. 14 shots until slowdown for both on my K-1. But cropping to APSC speeds up the framerate and goes up to 52 shots until slowdown.


I did some quick testing in FF mode. In RAW, the buffer can only take a certain amount of data until it's full. For example: I can take 13 shots at 1/250 or 23 shots at 1/8 until the frame rate drops. However, the 13 shots at 1/250 take 3 seconds and the 23 shots at 1/8 take over 6 seconds. Both equal roughly 4 frames per second.

In JPEG I get 45 frames at 1/1000 until the frame rate slows down and seemingly endless shots at 1/250 and 1/30 (I stopped at around 350 frames).

Turning on lens corrections (fat fifty) slows down the frame rate to approx. 1 fps starting with the first frame.

Thanks for doing that, much appreciated. You missed my one point however;

I already knew that selecting 1:1 for RAW makes no difference compared to FF, that is because (as I said) that the crop is not really 'real'. Taking a 1:1 RAW file to LR will show the crop section, however taking the same 1:1 RAW to RawTherapee for example can give you back the crop areas, proof that at the time the shot was taken it's still collecting the data from the cropped area.

I'm curious in Jpg mode if when acting in 1:1 if there is a similar performance boost like using the APSC crop mode, i.e. I doubt we can claw back the cropped areas from a Jpg version of the file... but I could be wrong, so I need to test that.

My take away message from the tests you have performed here is the following;

1) There exists a sweet spot for optimum/maximum amount of shots grabbed, it relies on some boosting of ISO at times. For example if taking slower shutter shots you can have the ISO low (1/30, ISO 100, under good conditions you can expect to get over 100 shots. But if pushing the shutter speed up to 1/250 you may need to boost the ISO to compensate, thus still getting a high amount of shots (100+). However there is certain shutter speed regardless of reasonable ISO given (1600 with 1/1000) that will result in quite a dramatic cut off (45shots), so shutter speed seems to be quite instrumental in determining how many shots can be taken in succession before reaching buffer. If someone wanted a very long burst session then we ought to keep an eye on the shutter speed and not let it rise too high.

2) Switching from L to M, S or XS has little impact on performance, probably to do with the fact its still recording data from the entire sensor (rather than crop and possibly 1:1, in jpg mode that is). However dropping IQ (*'s) does have an impact. The only question left now is that if the amount of shots obtained are similar between Jpeg L *** and Jpeg XS ***, does the buffer recover quicker once you hit it? I'm thinking it would simply be due to smaller files collected from the XS shots than L? So if you're happy to shoot M (22mp instead of 36mp) you might not get any more shots in the burst, however in theory the buffer will recover quicker?

You are in good company. Many of our users are not native English speakers and many use a translation service when posting here. @Brucebanner was just saying that the translation was not very good. I was also a little confused until I saw you are in Riga and might be a Russian or Latvian speaker. Our conversations here are generally pretty friendly and not as rough as some of the eastern Europe forums.

I can only guess how this comment translates back into Russian!


Steve

yes I was going to say that I think this was purely language barrier related.

[Ivan]

You are in good company. Many of our users are not native English speakers and many use a translation service when posting here. @Brucebanner was just saying that the translation was not very good. I was also a little confused until I saw you are in Riga and might be a Russian or Latvian speaker. Our conversations here are generally pretty friendly and not as rough as some of the eastern Europe forums.

I can only guess how this comment translates back into Russian!


Steve

The translation of the comment was correct. Thank you for your understanding. It was nice to read your explanation.

[sbh]

...

My take away message from the tests you have performed here is the following;

1) There exists a sweet spot for optimum/maximum amount of shots grabbed, it relies on some boosting of ISO at times. For example if taking slower shutter shots you can have the ISO low (1/30, ISO 100, under good conditions you can expect to get over 100 shots. But if pushing the shutter speed up to 1/250 you may need to boost the ISO to compensate, thus still getting a high amount of shots (100+). However there is certain shutter speed regardless of reasonable ISO given (1600 with 1/1000) that will result in quite a dramatic cut off (45shots), so shutter speed seems to be quite instrumental in determining how many shots can be taken in succession before reaching buffer. If someone wanted a very long burst session then we ought to keep an eye on the shutter speed and not let it rise too high.

2) Switching from L to M, S or XS has little impact on performance, probably to do with the fact its still recording data from the entire sensor (rather than crop and possibly 1:1, in jpg mode that is). However dropping IQ (*'s) does have an impact. The only question left now is that if the amount of shots obtained are similar between Jpeg L *** and Jpeg XS ***, does the buffer recover quicker once you hit it? I'm thinking it would simply be due to smaller files collected from the XS shots than L? So if you're happy to shoot M (22mp instead of 36mp) you might not get any more shots in the burst, however in theory the buffer will recover quicker?
....

Good points, I'll try them in the next few days. I wouldn't have expected that changing shutter speed and ISO would have an impact on how fast the buffer fills. If ISO is the cause then it would indicate that data processing is different at different ISO – as you said.

I would have thought that shutter speed has more impact in a way that slower shutter speeds leave less time between exposures to process. So at faster shutter speeds, the data gets to the buffer quicker and fills it up faster than it is written to card.

Perhaps I can test that in studio by changing ISO and shutter speed independently by compensating exposure with light instead of camera settings.

[BruceBanner]

I did a brief run of shots in Jpg mode with 1:1 activated, it didn't seem to shoot any faster than FF. Whereas Crop mode there is a huge substantial difference in fps rate.