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Messages - 1022mm

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Chronos User Discussion / Re: Spare Battery with charger for chronos 2.1 hd
« on: February 04, 2024, 06:18:39 PM »
I've run my 1.4 for about an hour plugged into an inverter powered by a car jumper pack, with more battery life to spare.  Cheap, and it works.  I regularly run my 1.4 for 6-10 hours at a time plugged into an inverter in my car. 

Chronos User Discussion / Re: Fitting the Micro Four Thirds Mount
« on: June 22, 2023, 10:12:50 AM »
I've been shooting using a C-to-EF adapter on my Chronos 1.4 since March of 2019 with great difficultly.  No C to EF adapter on the market is stable enough to shoot with the weight of a the 11-16mm EF lens.  The connection continually works loose, causing the backfocus distance to change which makes the lens go out of focus and require resetting the focus.  This happens nearly every time the camera is picked up, and I have countless shots ruined by being out of focus due to this issue.   I eventually bought a rail system to provide more support to the entire setup, but even this was not enough to stop movement of the lens on the adapter.

The MFT mount appears to have completely fixed this problem. I have a native MFT wide-angle lens and an MFT-to-EF adapter using the same 11-16mm lens, both are rock solid now and I don't need to keep using the unwieldy rail system.

Thank you, that makes perfect sense!  I'm likely going to go with some sort of a fisheye MFT lens, as it simplifies the setup and gives me a little wider frame than what I have with the 11mm lens.

I'm currently using a Tokina 11-16mm on the Chronos 1.4 using an EF to C mount adapter.  The field of view on the Chronos at 11mm and the full 1280 width setting (IE at 1280x720 at 1,502fps) is considerably more narrow - possibly two to three times more so -  than the equivalent field of view on my Canon EF DSLR.  I suppose then the question would be what would the EF crop sensor conversion factor to the Chronos be?

I'm familiar that the field of view narrows as you reduce the frame size to increase the FPS. The baseline I'd be looking at for a conversion factor would be at the full 1280 width on the Chronos 1.4 as it compares to the frame on a full-frame or crop-sensor DSLR.

I decided to get the MFT mount due to my ongoing problems with the physical stability of the c-mount adapter.

I suppose the bulk of my confusion comes from never using an MFT camera or lens before.   I know about the crop factor as it pertains to using a full-frame lens on a crop sensor camera, but many sources say that MFT lenses on a MFT mount all have crop factors of 2X.

Is there a nice shorthand way to calculate effective focal length and f-stop for lenses mounted on the Chronos using adapters?

For instance, I know that using the EF-to-C mount adapter increases the lenses' effective focal length (making it less wide) and raises the effective f-stop (making it slower).  Presumably, so does the new MFT mount due to increasing the distance from the sensor to the lens.  Even more so if using an EF-to-MFT adapter stacked onto the MFT mount.

I was hoping there would be simple conversion factors/ formulas you could use to predict how any given lens will end up when using various adapters on the Chronos.

For example using a 9mm F2.8 EF-mount fisheye with an EF-to-MFT adapter on the MFT mount might end up as a factor of 2, resulting in an effective 18mm F5.6 lens.  I was hoping there would be a nice easy multiplier you could use like that.

Any EF lens users with this new mount, what EF to MFT adapter did you end up using?  Most of the ones I see available have electrical contacts to pass through the autofocus and aperture control, which are unnecessary in this application.  However, most of the ones without the electrical pass-throughs are pretty low quality with bad reviews.  I need something that works well, but don't want to spend the extra money for the ones with the electrical contacts that I don't need.  I'm also hoping to minimize the hit on effective field of view and f-stop.

I'm also open to just getting a native MFT wide-angle lens.  Currently using the Tokina 11-16mm EF mount.

Chronos User Discussion / Re: Filming lightning
« on: April 06, 2023, 04:28:40 AM »
I do a lot of filming of lightning with the Chronos 1.4.   Keep in mind that what you are trying to capture with high speed cameras is the *leaders*, which are very dim relative to the very bright return stroke. The leader propagation is the interesting part of a lightning flash to capture in high speed, so you would expose for them rather than the bright return stroke.  This means the return stroke will almost always overexpose, but it's no big deal as it's not the part of the event that has much you can resolve at the Chronos' framerates.

Again, lightning leaders are faintly luminous and do not show up well on the Chronos unless they are relatively close (within 2 or 3 miles) or they are the brighter ones associated with a high peak current flash.   The fastest lens you can afford at its most wide-open aperture helps.   I am using an F2.8 wide angle lens, and I can capture most leaders within 3 miles distance.

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: November 13, 2021, 10:35:47 AM »
Thank you!  I am using a Tokina 11-16mm, EF-to-C mount.

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: October 26, 2021, 06:21:58 AM »
I started shooting above the 10k FPS mark on the 1.4 this weekend, and managed to capture two cloud-to-ground lightning strikes.  496 x 268 at 10,034 FPS.

Update after shooting with this rig all spring and summer.   In addition to the Camvate rail system, I bought a different brand of lens adapter - a Vello (first one was the Fotodiox).   The two brands are very similar.

Sadly, even with all of the bracing from the rail system, the simple act of repeatedly setting the camera down on the passenger seat of the car over months of use was enough to start loosening things up again.    The Vello adapter screws now require re-tightening after a day or two of use, and the camera's lens mount actually has started rotating slightly.  With the wide-open aperture (and associated narrow depth of field) required to get useable exposures in outdoor daylight, these even very slight movements often require refocusing the lens - a task very difficult without very bright daytime lighting conditions.   The loose lens adapter screws often allow the lens to wobble on its axis, meaning one half of the image is in focus, the other out of focus.

I have added a zip tie to further secure the lens to the rail's y-support, but this is only a stopgap.   My next measure will be to install a tripod head in my car to perma-mount the rig, so that the lens never encounters *any* lateral force. It appears just the weight of the camera resting on its side is enough to work it loose over time.  It certainly appears that a native mount is going to be the only long-term stable solution.

Again, I usually need to set focus during the day and rely on that setting for the evening and nighttime.   Getting a good focus set in the dark, even when the camera is set to 30fps, is many times impossible.

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: August 11, 2021, 08:55:44 PM »
This year I shot lightning footage at 6,000FPS (actually 6,002 FPS at 640 x 354) on the 1.4.  Here is the highlight reel of those captures:

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: June 22, 2021, 08:27:42 AM »
This year I've been shooting lightning with the 1.4 at 6,000 FPS.   (Actual framerate is 6,002 fps at 640 x 354).   The following is the best storm I've had for this purpose, with 17 captures at that setting.   I also had a 30fps camera recording simultaneously for most of them.

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: June 12, 2021, 10:22:58 AM »
Thank you!    It's challenging to get lightning shots to work well.   What you're really shooting with high speed is the initial "leaders" which are much dimmer than the main "return stroke" that other cameras are capturing.    These only tend to expose well within a couple of miles distance. 

Just an update to this thread.   I ended up going with a CAMVATE rail system to support the camera and the lens as one rigid unit.   This seems to have solved all of my focusing issues by eliminating all possible sources of movement.  The extra weight makes handholding for more than a few minutes at a time awkward, but I have production-tested this setup on the road during the past month, and it has held up very well. Thanks to all who offered suggestions!

Chronos User Discussion / Re: Chronos 1.4 Footage Thread
« on: June 05, 2021, 08:18:07 PM »
Hello all, I recently posted a highlight reel from two years of slow motion lightning video captured with a Chronos 1.4 at 1,500 FPS across the Great Plains & Midwest.

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