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Messages - Photopage

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Chronos User Discussion / Re: Extracting still images
« on: June 24, 2020, 02:30:26 AM »
Hi Photopage:

Sorry for the late reply.  Thanks for taking the time to try to verify the exposure.

In looking at the pictures, I am confused.  If each still is one microsecond exposure, why aren't the images much clearer.  In looking at the images, I have no idea what I'm looking at.

Thanks.

Hi rdemyan,
 I was using motion blur to work out the exposure duration.  No motion, no information.  So you are looking at a highly magnified image of a saw blade going at roughly 2000 rpm.  See attached jpeg for wide view.  Also, there was a good discussion about the differences in 2.1 and 1.4 sensors and how they deal with parasitic exposure.  You are right to choose the 1.4 for shorter shutter speeds.

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Chronos User Discussion / Re: Extracting still images
« on: May 02, 2020, 06:54:54 PM »
"The 2.1 can shoot with exposures down to a micro second.  I just tested it."

I've pretty much decided that I am going to buy one of the cameras.  The datasheet for the 2.1 says that the minimum exposure time is 10 microseconds and not 1 microsecond.  Would you please confirm that you were able to get 1 microsecond?

Also, is the fps really limited to 24,046 per the datasheet?  It seems odd for a higher resolution camera and given that the initial announcements for the 2.1 said the camera would be able to shoot 100K fps.

Thanks.


To test the 1 microsecond exposure I shot a 260mm diameter saw blade doing roughly 1800rpm.
To test the timing using household equipment only, I compared the distance between frames at 24000fps with the motion blur of the exposure at 1us.
jpeg of frame sequence attached
I know that this relies on the same piece of kit to both test and measure, but no-one is questioning the frame rates.
Looks good to me.
I also shot at 5000fps and got the same result, but there is no usable sequence at this micro scale, jpeg attached.
 

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: May 01, 2020, 09:24:48 PM »
Mostly 60mm micro Nikkor 2.8.  Some Nikon 50mm 1.4

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: May 01, 2020, 09:13:21 PM »
95% chronos, 5% Nikon.  The timelapse of the cake being decorated was shot on a nikon d4s, everything else was chronos.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: May 01, 2020, 09:02:14 PM »
some chronos 2.1 fun to promote a fine dining restaurant that's now doing luxury home delivery.  Made primarily for Instagram. @atticamelbourne @lunecroissant @colinpagephoto

https://youtu.be/44Oe9YlGQxM

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Chronos User Discussion / Re: Extracting still images
« on: May 01, 2020, 04:14:23 PM »
Anyone got any ideas about how to measure if the camera is doing what it says?  I think the maths is right, (1/24000)/360 x 8 for an approximate microsecond with an 8 degree shutter at 24000 FPS, but how do you test if that is actually what the camera is doing?
Happy to do the test if anyone has a method that can be with household items.

Exposure seems like the easiest option, but does the sensor have any reciprocity failure at very small exposure times?

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Chronos User Discussion / Re: Extracting still images
« on: April 29, 2020, 07:37:50 AM »
Hi, interesting discussion.  The 2.1 can shoot with exposures down to a micro second.  I just tested it.
Youíll need a lot of light, so using a flash as your light source is a good idea.
In my quick test, I used the highest standard setting, around 24000 frames per second and an 8 degree shutter to get the 1 microsecond exposure.  The camera crops the sensor to achieve very high shutter speeds, so resolution is greatly reduced.  At that speed I get a number of weíll exposed frames from a single flash.
I also tried at full resolution, but had no luck.  Thatís probably because I had no way of triggering the camera to the flash, and at full res the camera only grabs 1000 frames per second, and my little flash was most likely firing at around 1/4000th of a sec.  Iím sure you would get exposures if you tried for more than 5 minutes, or worked out a trigger / delay or used a longer duration flash.
You wonít get a million frames per second video by selecting an exposure of 1 us, but you will get a good 2meg still frame if you can figure out the light source or trigger, and a thousandth of a second later youíll get another still frame.
Sounds like fun

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: March 10, 2020, 03:00:07 PM »
Great result

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: February 14, 2020, 01:05:47 AM »
720p at 2000fps on Chronos 2.1 test
scaled up (automatically) in DaVinci Resolve

https://youtu.be/PKZ-PsBxJpo

and for anyone who's seen enough insects, these little guys eat em...back at 1000fps
https://youtu.be/4jxneiMJ5gI

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: February 13, 2020, 06:03:59 AM »
Gain test, just increased the gain as the sun was getting lower, leaving FPS, shutter angle and lens aperture on the same(ish) settings.

https://youtu.be/e7yymUQaXjw




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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: February 12, 2020, 01:26:02 PM »
Blue Skimmer dragon fly
https://youtu.be/lEF-KF-5rD4

Looks really great and sharp. Though it almost looks like it was shot in 500fps and slowed down to look like 1,000, is that because of the motion blur?

I'm still a lens noob but is that motion blur effect caused by the F4 aperture or the 357 degree shutter?
That is just the (basically almost full) 360 degree Shutter, that makes everything look like that.
That is also the Reason, why the common reccomendation is to use 180 degree shutter. This gives some amount of motion blur, but not too much, also 180 degree Shutter was used in Cinema Movies for a very long time, so we are very much used to the look of it.
If you go far below 180 degree, like, lets say 18 degree, your individual Frames will look Sharper, but the clip istself wont look as Smooth. For Pans or Fast Camera Movements, also anything in The Frame that moves Quickly will Look choppy. This is often used in Action Scenes or other Very fast Scenes to make it look more intense or harsh (maybe not alway as extreme as 18 degree, maybe more like 90 or so).
If you go way above 180 degree, like here 360 degree, everything just blurs together and it also looks odd. Thats why 180 degree is mostly preferred for Cinematic Shooting.
For Science and such, there may be other factors that come into play when choosing an Shutter angle. For example, if you know there will be a lot of very fast moving Objects, and want to actually get Sharp images of those, while in the air, you want your Shutter angle as low as possible and so on...

Yes Marcus, it was shot at 1000 FPS, but I wanted to slow down the playback to see more detail.  This is 10 FPS, so 100 times slower than real life.
Nikon1 has nailed the 357 Degree blur effect description.

I was trying out some options and playing around with the shutter angle to increase exposure while keeping the gain on zero, and the lens on f4 for a little more depth of field.
If anyone can tell me how to make insects stay in my plane of focus Iíd appreciate it!

Love the quality of the image at zero gain.  Will try higher settings today, and go back to narrow shutter angles for sharpness.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: February 12, 2020, 05:09:44 AM »
Blue Skimmer dragon fly
https://youtu.be/lEF-KF-5rD4

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Chronos User Discussion / Re: 11 second chronos 2.1 clip
« on: February 10, 2020, 12:56:00 AM »
Thanks Kron team,

received my 2.1 today.  Love the serial number.
here's a link to a little late afternoon daylight test
https://youtu.be/ytQchDACNkE

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Thanks for all the discussions on this topic.  I'm looking forward to receiving a Chronos 2.1 some time soon and I'm doing all the normal preparations, thinking about lenses, lighting and RAW processing workflow.  This thread has helped confirm my hopes that image quality is very good.
I've had a quick play with Aaron's dng files from his Pentax lens and uploaded the results here      https://vimeo.com/332620537

These images had lots of room to play, perfectly exposed and easy to fix the colour.  The colour chart was helpful too.

I'm a photographer and I used my normal tools, a calibrated Eizo screen, Capture One Pro to grade the files and Photoshop to output a video format.  I cropped to 720p for speed of upload.
There may be a better and easier way, but it's good to use the tools you are familiar with.

Cheers

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