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Topics - 1022mm

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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.

Chronos User Discussion / High-quality C-mount lenses?
« on: May 09, 2021, 04:48:28 PM »
Per my last thread, I'm struggling with the C-to-EF mount adapter stability.   I'm not seeing any better C-to-EF adapters available than the one I already have, and I'm at the point of buying a rail system to support and secure the lens.   Rather than deal with all of that, I'm now curious about just going for a native C-mount lens.  When I look at those, however, it appears they are tailored mainly for CCTV camera applications and not photography/cinematography.   I'm willing to spend the bucks on a high quality (sharp and fast) wide-angle C mount if one exists.   Is anyone using such a lens?  Thanks again!

The E-mount adapter I'm using with my Chronos 1.4 has an issue with the three compression screws on its base constantly loosening with the slightest provocation.   This makes the lens "wobbly" and is often enough to affect the focus, leading to many ruined shots.   I have to carry a jeweler's screwdriver everywhere I go to keep them tightened, but it doesn't take much to re-loosen the screws.

This isn't really a problem with the Chronos per se, but is an issue created by the very small-diameter C-mount having to support the weight of DSLR lenses.  I'm using either a Canon 10-22mm or Tokina 11-16mm lens with my Chronos - not huge lenses, but big enough that the stresses on the small C-mount connection are enough to work things loose easily. 

Is there a good C-to-E mount adapter that would be more secure, or maybe some type of cinema-like rig that can support both the camera and the lens on a common frame?  Thanks for any suggestions!

I upgraded my software setup to Photoshop CC to have better control over the CinemaDNG files from the Chronos.    Everything I've shot after upgrading the camera's firmware to v0.3.1 works just fine.  However, some - but not all - of my older files shot before the firmware update (back when the raw to dng conversion script was used) are exhibiting a strange problem in the RAW editor.

Here's the file unedited straight from the camera after DNG conversion (see attachments below for full size):

When first opening the file in Camera Raw 11.3, the image has a "gray haze" with nearly 90% opacity, as if brightness has been cranked way up and contrast turned way down (see attachments below for full size).

Moving any of the raw setting sliders only applies those changes to the "grayed out" image - with one exception.  When you make the tiniest adjustment to the white balance slider, viola, the image suddenly shows correctly, and you can then make normal RAW adjustments to the other setting sliders.   The edits display correctly in Bridge and in previews.

However, if you go and add a spot healing to the image, the spot heal shows a black box in the final image, in Bridge, and in previews.    Re-opening the edited image in Camera Raw with a spot heal results in this (see attachments below for full size) - totally whited-out image with a green box where the spot heal is:

In all of those images, you can see the correct image in the "filmstrip" in the upper left, but this is not what is getting saved to the final image.

Does anyone know what is going on?   Again, some of my old files do this, some don't.

EDIT: can't figure out how to insert full size images inline, so to view these in full size, the corresponding attachments are below.   I tried using the bbcode img tag, but these are showing the thumbnail - grr

Software Dev / Problems after reverting from v0.3.2 back to v0.3.1
« on: June 21, 2019, 09:56:54 PM »
I installed the version 0.3.1 update early today and ran some test shots to ensure everything was working.   No problems.   I then applied the v0.3.2 update.   After letting the camera warm up for 40 minutes, I did the factory black calibration followed by another manual black calibration.     When I went to start shooting, there were multiple narrow vertical bands about 1 pixel wide across the frame (example attached) that would not go away with additional black calibrations.  This banding is very visible even on the LCD screen in both live and playback.  Note that I have had problems with banding not going away on my camera before this update, perhaps there is an issue with my camera's sensor that is causing this?

So, I reverted back to the v0.3.1 update, which was successful.   However, there are two problems that haven't gone away with several reboots:

1.) The "No Batt" indicator displays at the bottom.   The camera still operates without the external power adapter plugged in, but the "no batt" indication remains instead of the normal percentage remaining.

2.) The camera will not power down using the main power button.    A "hard" power down (holding the power button for 10 seconds) is the only way to turn the camera off.

Other than those two issues, the camera seems to be working normally (shooting, saving files, etc), though I have not yet put it through its paces on a normal shoot.

The attached image below is a frame after installing v0.3.2.  It is nighttime here and I am on the road, so no well-lit scenes were available.

Chronos User Discussion / Maze artifact with 1.4
« on: June 21, 2019, 03:43:47 PM »
Shooting in RAW, 1280x720, 1502fps today my video has this "maze" artifact across the entire image on every frame as well as a huge hue shift.   Normal black calibrations done before the shot.   Camera was on for about 20 minutes prior to the capture.  Anyone else see this before and know the cause?  I have been shooting with the same settings all year and this is the first time I've encountered it.

I was able to correct the hue shift in Photoshop's RAW editor, but the maze pattern remains.

First attachment below is a crop of the frame at 100%, second one is enlarged 4x.

Chronos User Discussion / Filename time stamp question
« on: May 09, 2019, 02:44:21 PM »
Is the time in the filename the time the video was captured into RAM, or the time it was saved to the storage medium? Thanks!

Have any shots been done on both the 1.4 and 2.1 in similar/identical lighting to show how much increased light sensitivity the new sensor will yield?   I do quite a bit of outdoor shooting where ambient light is the best I can manage in many situations.   Eager to see how the 2.1 improves in this area!

I just finished a three-day shoot with my new Chronos.  I'm very excited to have this new tool in the arsenal and I'm looking forward to putting it to good use during additional projects in the coming months.     Here's a quick rundown of my experiences.

- The camera was completely free of any software bugs or glitches.   No lockups, errors or anything else to report.

- Resolution/framerate were kept at 1280x720@1502fps for the entire project, and saved in RAW.  I ordered the SSD but it didn't arrive before this project, so I saved to the SD card.  No dropped frames were encountered.

- Lenses used were Canon 10-22mm for 95%, with some Canon 50mm 1.8 shots.

- The camera was powered on continuously for 8+ hours per day, with some recording intervals exceeding 5 minutes (waiting for just the right subject event to occur before triggering).   Absolutely no overheating issues or any other negative performance problems.

- We were shooting with natural light (large outdoor scenes) with many parts of the field of view not being well lit, especially later in the evening.   This resulted in pronounced vertical sensor banding.   I was unable to get rid of the banding despite numerous and frequent black calibrations.   Black cals were done at power-up and at regular intervals throughout the day, but they did not have a noticeable effect on the image.   Topaz denoise worked well for the most part to correct for this in post, though some shots were unsalvageable.

- The most difficult part of the workflow was focusing.  The edge highlight function is not reliable enough to depend on in production.  I ended up using trial and error, importing the video to a computer each time to check the focus, then marking the focus ring on the lens when I got it right.  The screen has a lot of noise in lower light, making focusing in those conditions, even using an external monitor, next to impossible.   I also had weird depth of field issues I'd never seen before.   At infinity, with the foreground all the way to objects about a mile distant in focus, the most distant objects were noticeably out of focus (including clouds in the sky and a city skyline backdrop).   I could not fix this problem.   It may be with my lens or possibly a backfocus problem, but I'm not really sure.  Anyone have any ideas?

A big request for future firmware would be the ability to pinch and zoom on the screen to enlarge objects to make focusing a little easier, plus maybe a "temporary max exposure" button to brighten the image temporarily for focusing purposes without resetting the resolution/framerate.   

- The Chronos shots were used with 1080p clips shot with other cameras.  The final project was delivered in 1080p.  I upscaled the Chronos' 720p to 1080p with relatively good success using "A Sharper Scaling" software.

In all, we were very pleased with the results we got from the Chronos.  It is really a game changer to have something like this on the types of projects I normally work on, it's a capability I didn't expect to have access to.

Chronos User Discussion / Black calibration best practices
« on: March 20, 2019, 10:16:10 AM »
I've been spending the past few days ironing out the kinks of my camera setup and workflow.  Everything is working great so far, with the exception of the vertical sensor banding.    I haven't been able to get consistent reduction in that using black calibration.     Is there a best practice for this?   I read on the blog that they had some success doing two black calibrations approximately 20 minutes apart, one at startup and a second after the camera had warmed up.    That hasn't worked as well for me yet.  I'm making extra sure the lens is completely blacked out when doing my calibrations.   Is there anything else I should be doing?

Has anyone had success generating a mask of the banding to correct in post?  Thanks!

Edit: I'm shooting at 1280x720 at the max framerate (1502) at default exposure settings (0db gain, etc) and saving in RAW.  Attached an example - 2 black calibrations about 5 minutes apart were performed before this was shot.

Chronos User Discussion / HDMI support
« on: March 18, 2019, 01:42:01 PM »
Hello all, sorry for being the annoying newbie, but I have a question regarding HDMI.  Is it currently supported?  The manual says it's not active yet, but the latest firmware specs say it should be enabled now.   I tried two monitors - both see the camera (monitor input shows an active signal) but the screen is black for both live and playback.  Is there a setting I need to toggle?   I couldn't find anything myself.  Thank you!

Chronos User Discussion / SSD rig parts list
« on: March 16, 2019, 02:58:33 PM »
I'm looking for some guidance on what is necessary to get my Chronos set up with a SSD.   I went to a large computer parts store (Micro Center) but got blank stares from the techs when I showed them what I was trying to accomplish.   

The problem apparently is that the eSata cable doesn't support powering the drive through the camera port.   On another thread, I saw an eSata-p cable mentioned, but I couldn't find such a thing being sold nor did anyone at the store know what it was.

I'm a bit of a newbie when it comes to eSata, so I might just be missing something simple.   Does anyone have a parts list of what they used to get a SSD setup working with the camera?  Thank you!

Chronos User Discussion / Infinity focusing in the dark
« on: March 15, 2019, 03:58:50 PM »
I'm a new Chronos user that will be doing some outdoor shoots this spring and summer.  Some at night (things like fireworks and hopefully some lightning strikes).   I'm using mainly Canon lenses with a EF-mount to C mount converter.

I've done a few trial runs at night, and I'm running into some difficulties with focusing.   Low-light scenes don't show up with enough clarity to focus using the Chronos LCD screen.   With my DSLR, I can get a nighttime infinity focus lock using things like distant streetlights and car lights, these are things that understandably won't show up at all on the Chronos LCD.  I have an external monitor on order, but I'm assuming it won't show much either.   I've tried getting a focus lock using my DSLR, then moving the lens over to the Chronos without any success.  I've also tried doing a daylight focus at infinity, then marking the focus ring on the lens for later.  The problem is that some of my lenses' focus rings are electronic without hard stops, meaning that marking the ring at a certain position doesn't guarantee that the internal focusing mechanism will actually be in the same position later.

Would it be possible to adjust the Chronos backfocus to exactly match my DSLR? That way I can focus a lens using the DSLR, then transfer it to the Chronos.   Right now that's my best idea, but wondering if anyone else had any other methods that have worked for you.

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