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Topics - wilheldp

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Chronos User Discussion / Focusing Troubles
« on: October 03, 2017, 05:30:38 PM »
I have shot several videos with my camera now, and I'm having a lot of trouble getting the subject in focus.  I am using the focus peaking, and try to get the greatest concentration of cyan dots on my subject, but everything I shoot seems to come up ever-so-slightly out of focus.  I rarely use the kit lens down to F1.2 (shoot mostly in bright sunlight or with Godox + Fresnel directly on subject), so I don't think tiny depth of field is my problem. 

Does anybody have any tips for proper focusing?  I'm assuming this is just a photography problem (I don't have a lot of experience with manually focusing video lenses), but I can't seem to grasp it after 20 or so videos.

Software Dev / Saving, Software Request
« on: September 25, 2017, 04:02:48 PM »
EDIT: I figured out what I did wrong while writing this post.  It turns out that the SD card I was using was previously used as a boot disk for a Raspberry Pi.  While it was an 8 GB card, it had been formatted FAT16 with a 60 MB boot partition.  The behavior I describe below was what happens when you run out of space on your SD card.  I'm going to go ahead and post this for two reasons.  One is to let people know what it looks like when you try to save to a full SD card.  And Two, to make a software request that an error message be added to the camera software to let you know that your SD card is full instead of entering an endless save loop.

I got my camera today, and everything was in great shape.  Only issue was the backfocus screw not being tight (ended up turning the C-CS adapter when I installed the lens for the first time).

My first shoot was the obligatory water droplet, and everything went fine.  Marked in and out, and saved.  mp4 file works fine.

My 2nd and 3rd shoots were the obligatory lighter strike and a small firecracker exploding.  On both of these, I marked in, marked out, and hit save.  The save buffer went through the marked frames, but then it started over from 1 and went through all 8700+ frames...repeatedly.  It got stuck in an endless loop both times, and I had to hard reset it both times.  The files created during this process are corrupted and won't play.

For comparison, my successful water droplet video is 14 seconds long and ~35 MB.  The failed videos are 4 MB and 2 kB.  I think the size of those files is a function of number of frames it was at when I hard reset the camera (the second time it happened, I knew to look for it, so I reset the camera right after it restarted saving from frame 1).

General high-speed discussion / Measuring Speed
« on: September 18, 2017, 12:39:10 PM »
Is there a proper name for the backing board that you can place behind a fast-moving subject to measure its speed?  The Mythbusters used them all the time, and I've seen them on some ping pong cannon videos too.  Basically, it is black and white lines of known width (inch/foot, or metric markings).  If you know the frame rate of the camera and playback frame rate, you can measure the exact distance that an object moves between frames, and calculate its speed.

I'd like to do some of those experiments with my Chronos.  I can probably make one, but if they are relatively cheap to buy, I'd rather go that route.  I don't have a lot of spare time at the moment, and I'd be worth it to me to just buy such a board unless they are exorbitantly expensive.  As of yet, I've failed to find a string of search terms on Google or Amazon that gets me what I want.

Chronos User Discussion / New Pre-orders
« on: August 08, 2017, 05:58:54 PM »
I see that the pre-order page now says that orders are scheduled to ship at the end of August.  Is that still an accurate estimate?  Is that the timeframe where the store page will switch from pre-orders to just in-stock or BTO orders?

Also, are there plans in the works for a "next-gen" Chronos with a throughput higher than 1.4 Gp/s, or will there be quite a bit of time spent refining the software rather than working on hardware improvements? 

I really want to pull the trigger on one of these, but I'm a little gun-shy.  At the moment, I'm already 1000 GBP in the hole after Graham Rowan failed to deliver the FPS1000 after I made a deposit (I know...I know...I've seen the comparison between the low-end FPS1000 and Chronos.  I'm just bitter that I have neither my deposit back, nor a camera, no matter how crappy). 

Also, I have a near-term use for the Chronos at work, so a long delay may get me in hot water.  The alternative is to pay for a rental on a Phantom which would cost nearly as much as the Chronos (just for the rental), and would be overkill (don't need Phantom performance for the task at hand).

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