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Messages - Photopage

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: June 03, 2021, 06:42:23 PM »
Penfolds Wine https://www.youtube.com/watch?v=yjpcpZa6CHs
Bottle rotation shot on Hasselblad with Phase One IQ160 back (for use as stills on posters), all other movement shot on Chronos 2.1 with Nikon lenses. DaVinci resolve for colour and editing

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Chronos User Discussion / Re: Why the vertical color bands
« on: December 16, 2020, 03:01:27 PM »
I suspect you are experiencing increased noise because you are under exposing your images.
Think about Signal to Noise ratio.
In photography the signal is Exposure. Think of the sensor noise as a constant, although external factors like heat can increase noise. 
At correct exposure the noise is not visible.  As you begin to under expose you images (reduce the signal strength) the noise becomes more visible.  If you find that you need to brighten the shadow areas of your image in Post production, you will see noise in those parts of the image, because post production adjustment increases both the signal and the noise, making the noise more visible.
Using analogue gain in the camera will help, but will also increase the noise.  Digital gain just increase signal and noise together, ie no advantage if your goal is quality.
For noise free images use more light, closer to the subject, use faster lenses and read the many posts on this forum about this subject.  If you cannot do this you will not fix the problem.

If you are sure that your zero gain image exposure is perfect, post the DNG file so others can help you assess.

The noise has nothing to do with colour issues.  Re colour, buy a grey card/ white card, use the custom white balance feature on the camera, shoot RAW and make fine adjustments in post production, or you might have to learn to love purple.

As for the chef shot,  this image is both under and over exposed in the same frame.  Unfortunately you cannot fix this image.  It was doomed from the start because of the lighting.

Some people think photography is about cameras and lenses, when the most important thing for a professional is the lighting.  This is a classic example of too much light in the specular highlight on the stainless steel sieve and not enough light everywhere else in the image.  Watch some you-tube videos on lighting techniques and have another go.  You have lots of good options here, like a side or back light, and most photographers use more than one light for a reason.

Here's a good hint, If you are standing at the mouth of a cave looking in, the light would be very similar to the chef image.  If you want the chef to look like he's in a cave, you've nailed it. 
If you want him to be in a nice bright kitchen, light the background.  If you want him in the dark, and your attention is on the stuff falling out of the sieve, then backlight the stuff falling out of the sieve, and leave the area behind the action nice and dark for contrast.

Lighting is hard, but once you start thinking about it you will see a dramatic improvement in your images.
FYI I am a professional photographer with 35 years experience and I am still learning and enjoying the challenges of making amazing images every day.  The Chronos 2.1 can make beautiful broadcast quality images, but you will need to work hard to get those images.  Not bad for the price.

Good luck!
Col



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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: October 19, 2020, 07:14:20 PM »
Another one, Laowa 24mm PROBE, 1000 fps, 18 db gain and a lot of noise reduction.

Does anyone have any suggestions how to get rid of the vertical lines from the sensor? Is there any special software.

DaVinci Resolve 16 studio version $299 US. You can download the free version and see a watermarked preview.
For this kind of vertical banding I have use Fusion, Revival, Deband.


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Chronos User Discussion / Re: Review of Chronos 2.1
« on: October 11, 2020, 07:03:48 PM »
Hi Sergey,

sounds like you have a problem with your camera.  I save everything through esata to SSD and it works perfectly.  I've made over 100 saves in the lase two weeks and the camera has not hung once. 

Have you tried to update or reinstall the firmware?

Cheers,
Col


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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: October 11, 2020, 06:58:37 PM »
walking through grass with Gimbal
https://youtu.be/S26uWyOLue8

Wine pour
https://youtu.be/HMf8QtQxrUE

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: October 09, 2020, 07:09:23 PM »
walking though long grass, no gimbal, no stabiliser test.  https://youtu.be/pCWv7Esp_-o
will do a gimbal test tomorrow.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: October 05, 2020, 04:59:03 AM »
Good bright studio shots Martin.  What lights are you using?
Col

Wow! Yes, really nice shots! Great.

Yet another test throwing a lime through water.

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: October 01, 2020, 05:30:09 PM »

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Chronos User Discussion / Re: One line of lighter pixels in saved video.
« on: September 27, 2020, 02:28:39 PM »
I now do lots of Black calibrations when Iím working.  As the camera starts up and slowly gets hotter I Black Cal for every take.  Once the camera is running at a constant temp I do a calibration about once an hour.  Any change of Shutter angle / shutter speed needs a new Black Cal, and any other changes like FPS and sensor size, black cal.

I dont like the exposure slider.  Itís way too easy to change the shutter settings, and looks the same as the playback slider, which I use all the time.  Iíve accidentally changed the shutter dozens of times by mistake.

Hope your line is fixed now?

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: September 11, 2020, 09:36:27 PM »
Had my 2.1 for 12hrs now took it into the garden shots some frames. EF to c mount adapter using canon EF lenses. H264 lut applied in resolve. this camera is the real deal, worth the wait.

https://vimeo.com/457154964

Amazing images!  Good to see more Aussie Chronos users

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Software Dev / Screen Brightness Control
« on: September 09, 2020, 05:08:15 PM »
I have a 2.1 and the screen is amazingly bright. Great for outdoor shooting in sunlight.  But when I'm shooting in the studio I would like an option to control the brightness down to a level that matches the viewing conditions.  Would this be something that a future update could include?
Love the camera, thanks!

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Chronos User Discussion / Re: Post Chronos 2.1 clips here!
« on: September 07, 2020, 07:13:35 PM »
Drinks test with 2.1 and Hive Plasma lighting
https://youtu.be/TS7iinpBuqA

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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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