Page 4 of 4 FirstFirst ... 234
Results 46 to 56 of 56

Thread: Auto Calibration for sources

  1. #46
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    Brian,

    I'd need to wait until tomorrow to find out the specific brand and length of cable, but we use component cables from both HDR-FX1s. However, and I know this is a red flag, for one of them, we have x cable connected to y cable connected to Sony's component to camera cable, while with the other one, we have just the y cable connected to Sony's cable. I might add that y cable is fairly flimsy. Is it imperative to have identical length and brand of cables for each source? Do you have any recommendations for good component cables?

    It's a shame that the Sony cable is incredibly flimsy.

  2. #47
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    The component cables we are using are:

    For Camera 1, from the Tricaster (with BNC adapters) a 10-foot long version of this cable:
    http://www.amazon.com/Steren-Python-.../dp/B000EA1LXQ

    Connected to one of the these:
    http://www.svideo.com/rgb12extension.html

    Connected to the Sony cable that connects to the camera's port.

    For Camera 2, we are using just the second cable (connected to the Tricaster with BNC adapters) connected to the proprietary Sony cable.

    Any suggestions? Is it better to use BNC cables with an adapter at the end to connect to the Sony cable, or to use component cables with the BNC adapter to connect to the Tricaster?

    What is the difference in quality, if any, between the following two cables, for a camera to Tricaster distance of only 25-40 feet?

    http://www.bhphotovideo.com/c/produc...Component.html

    http://www.bhphotovideo.com/c/produc...rformance.html

  3. #48
    Registered User
    Join Date
    Apr 2008
    Location
    Burlington, ON
    Posts
    156
    Considering replacing your current cabling with a better quality 75 ohm video coax in a multichannel snake with BNCs. You could use a couple of 50 foot mults, one per camera. This will allow you to continue working in your component workflow for connecting the cameras to the Tricaster.

    Suitable products are available from a variety of manufacturers... Belden, Canare, Clarke, Gepco, etc.

    Below is an example of the Canare 3 coax mult cable available from major supplier... customer has to terminate the ends or they can do it for you for an additional cost.

    http://www.markertek.com/Cables/Bulk...ca/V3-5C.xhtml

  4. #49
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    Excellent recommendation Brian, thanks.

    Here's a semi-unrelated question: I adjusted the brightness of the image from each of the two cameras (with the lens cap on) using the proc amp controls in the Tricaster, setting it to 7.5 on the waveform. After doing this, I'm still getting parts of the background of my set to come up as below 7.5 IRE on the waveform. Why is this?

  5. #50
    Registered User
    Join Date
    Apr 2008
    Location
    Burlington, ON
    Posts
    156
    I would suggest that you try the following:

    1) Set both camera to BARS mode, and then either use AUTO CAL or manually adjust the level or the camera bar signal at the Tricaster.
    If you adjust manually, follow this order:

    i) BLACK LEVEL or SET-UP/PED
    ii) VIDEO LEVEL or GAIN
    iii) CHROMA LEVEL or SATURATION (colour)
    iv) HUE or CHROMA PHASE (colour)

    When complete, switch both cameras back to CAM (BARS output off)

    2) Check the settings on each camera via the MENU:

    i) Switch ND off (I assume you are shooting indoors)
    ii) Null the COLOUR LEVEL and COLOUR PHASE for each camera, setting 0
    iii) Make sure AE SHIFT, and WB SHIFT are also set to 0.
    iv) Make sure the AGC / HIGH GAIN mode is set to 0db.
    v) Make sure the at the SHUTTER is not activated.

    3) Now shoot the your WHITE BALANCE card on both cameras, ideally positioned side by side, and under the same light source/condition.

    4) Manually adjust the IRIS + / - so that the white card is properly exposed. Use the ZEBRA mode set to 100, the card will be properly exposed to 100 units when you reduce the IRIS so that the diagonal highlight lines or the ZEBRA are gone from the Viewfinder or LCD screen display. You can slowly adjust the IRIS up and down slightly in order to better find this point.

    5) Activate the AWB - Auto White Balance - for both cameras

    At this point you can check the output of both cameras at the Tricaster.

    Ideally, the white card should appear uniform on the screen as you cut / take between the two camera sources. Also, the level should be uniform on the waveform display, and the the vectorscope. The white card should appear as a small circle, centered equally at the X and Y axis of the display.

    Refrain from making any adjustment to the performance of camera video at the Tricaster. If you see differences between the two cameras, double check the video path by switching the cameras back to BARS. Again, the BARS signal from each camera should appear equal between both cameras.

    If the BARS signal is appearing the same, but the WHITE card appears differ between one or both cameras, you should adjust for this difference at the camera. Use the WB SHIFT adjustment to make final adjustment.

    Now you can have both cameras shoot the "set" under normal set lighting conditions. Readjust the IRIS / exposure as required.

    Continue to visually evaluate the look of both cameras at the Tricaster. And again, refrain from adjusting for camera quality at the Tricaster. Use the Tricaster AUTO CAL or PROC adjustments in conjunction with the camera BARS signal to ensure that the video signal path is calibrated for proper set-up. video, chroma level and hue spec.

    Once you are happy with the match / look of the cameras shooting talent on the set, you can store this set-up into one of the camera memories. You would do this for each camera.


    Not sure if you have the operator manual for the HDR-FX1. You should refer to pages 34 thru 36.

    Here is a link to an url where you can access the manual if you require it.

    http://www.manualowl.com/m/Sony/HDR-FX1/Manual/245
    Last edited by Brian Mirrlees; 08-27-2012 at 11:46 PM.

  6. #51
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    Thanks for the advice on the proper procedure. A couple questions:

    1. If after auto-calibrating on the Tricaster using the camera's color bars the waveform shows a lower than 7.5 black and a higher-than 100 white, should I adjust brightness and/or contrast in the proc amp controls to put those in the right limits? Also, should the proc amp controls be used to adjust brightness and contrast if, when shining on the white card with the right exposure, it appears above 100 IRE?

    2. The issue we are having in the studio is that we have different lights, with slightly different color temperatures, on talent 1 (camera 1) and talent 2 (camera 2). In fact, there are two issues. One is that the color temp doesn't match PERFECTLY between the key and fill lights on each of the two talents, and secondly, that the color temp is unequal between the talents. Assuming I don't change the lighting setup by buying identically-colored lights, should I white balance each camera to its respective lighting condition? If I white-balance cameras 1 and 2 to the same lighting conditions (e.g. camera 1's lights) I know for a fact the white balance will be off, as expected, when I move camera 2 back to its condition.

    I realize that the ideal situation is to have lights with the same color temp, but it sounds like the best way to do this is to white balance separately and then adjust the WB shift in the picture profile in each camera to get them exactly right. Am I wrong?
    Last edited by celtics23; 08-28-2012 at 12:49 PM.

  7. #52
    Registered User
    Join Date
    Apr 2008
    Location
    Burlington, ON
    Posts
    156
    Quote Originally Posted by celtics23 View Post
    Thanks for the advice on the proper procedure. A couple questions:

    1. If after auto-calibrating on the Tricaster using the camera's color bars the waveform shows a lower than 7.5 black and a higher-than 100 white, should I adjust brightness and/or contrast in the proc amp controls to put those in the right limits? Also, should the proc amp controls be used to adjust brightness and contrast if, when shining on the white card with the right exposure, it appears above 100 IRE?

    Yes, you should be able to do this... adjust for the black level first, then adjust for the video level second... but only relative to the BARS signal from the camera.

    Question... by how much do the 7.5 black, and 100 white levels differ.? Can you try connecting the COMPOSITE video output from the camera to the Tricaster composite inputs and check if the level is the same or different.

    Also, if you have a contact at a local broadcast station or production house, ask if you could bring your cameras in to check the BAR output level on an external waveform and vectorscope... This would help isolate the level problem even further, maybe the levels out of the camera are low/high.... just a thought for further troubleshooting.

    If you are satisfied with the level of BARS from camera to Tricaster, either using component or composite outputs, and you still have have a high or peak white on the white card, then you should adjust the IRIS on the camera to reduce the light level accordingly (again, an easy check is to use the ZEBRA in the camera LCD/Viewfinder).

    Quote Originally Posted by celtics23 View Post
    2. The issue we are having in the studio is that we have different lights, with slightly different color temperatures, on talent 1 (camera 1) and talent 2 (camera 2). In fact, there are two issues. One is that the color temp doesn't match PERFECTLY between the key and fill lights on each of the two talents, and secondly, that the color temp is unequal between the talents. Assuming I don't change the lighting setup by buying identically-colored lights, should I white balance each camera to its respective lighting condition? If I white-balance cameras 1 and 2 to the same lighting conditions (e.g. camera 1's lights) I know for a fact the white balance will be off, as expected, when I move camera 2 back to its condition.

    I realize that the ideal situation is to have lights with the same color temp, but it sounds like the best way to do this is to white balance separately and then adjust the WB shift in the picture profile in each camera to get them exactly right. Am I wrong?
    It seems by your description that you are working in a situation with mixed or different light... and I would suggest this is the root of you problem.

    Are you sure that you have two light sources of different colour temperature, like tungsten or fluorescent light? Or are you confusing colour temperature with COLOUR MEDIA gel (Rosco, Lee, GAM) used on light fixtures to change the colour to a wash of colour used for dramatic effect?
    Last edited by Brian Mirrlees; 08-28-2012 at 05:16 PM.

  8. #53
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    I've attached a screenshot of what today's show looked like. Now, bear in mind that I'm waiting on an extra bulb to come in for the fill light on camera 2 (on the right, the guy with the headphones on),which should reduce the shadow on his right cheek and shoulder. Also, we are working on lowering the brightness of the monitor behind camera 1 (the monitor with the logo), and on trying to reduce the horrible glare on his desk, which is coming from his key light.

    The key light on subject 1 (again, on the left) is a Coollights 5600K fluorescent tube fixture. The fill is an intefit CFL unit with bulbs that claim to be 5200K (with the white diffuser which might raise the temp a bit). His backlight is a lowel omni with a full daylight gel.

    The key light on subject 2 is a supposedly 5400K and his fill is an interfit CFL unit with bulbs that very mysteriously say that are between 5000-5500K (!!). We don't yet have a backlight on subject 2.

    Apart from any other observations you might make about the shot comparison, would changing the tubes and CFLs of the lights to identical-color temperature and high cri lamps work to reduce these issues, or is this a fluorescent light issue that can't be resolved even with high cri, "high quality" lamps?

    Also, on a side note, I've been able to find kino-flo quality tubes online, but is it possible to get production-quality CFL bulbs with a definite color temperature, and if so, where?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	shot-comparison.jpg 
Views:	124 
Size:	77.1 KB 
ID:	106574  

  9. #54
    Registered User
    Join Date
    Apr 2008
    Location
    Burlington, ON
    Posts
    156
    Honestly, the pictures look pretty good judging by the screenshot you provided.

    I understand about the replacement lamp for the CAM 2 side fill fixture... I agree with you that, that should solve the problem with the shadow.

    For the reflection on the desk top, if you don't already have flags (like from a Matthews grip kit) you can easily improvise with using some "foam core" board - used for graphic art displays. We use it all the time, cuts very easily with a utility knife. Available in black and white surfaces. Cheaper too than a flag set.

    The brightness on the left monitor (logo loop) didn't bother me...

    Good call on using the 5500K range of light since you are working with live monitor screens on the set. Looks like you just have to make some tweaks on the larger LG screen.

    Another trick to try, is to route colour bars to the on set screens, and then shoot the screen with one of the matched cameras. Make adjustments to the on set monitor while looking at the feed of the camera on PGM out. Remember, you aren't trying to make the on set screens look good to the eye, but rather to the camera. Make sense?

    The only other thing I could suggest is to apply some make-up / powder to the on camera talent. Nothing major, but a little powder will help to even out the skin tone, and take off some of the shine from natural body oil and perspiration. If you do choose to try a make-up powder, make sure you use a product designed for television/video work. It should have a proper TV base. The problem with using regular make-up cosmetics is that they tend to have a yellow, or greenish base colour. This can make the talent look somewhat sickly looking on camera...

    I have no experience with the CFL lamps that you are using. I do work regularly with Videssence, Kino-Flo, and ARRI fluorescent fixtures, but the design and nature or the lamps is a bit different from the CFLs that you are working with.

    However, I would advise on standardizing / using one type of lamp and to use one with a colour temperature which is in the range of 5500K to 5600K colour temperature.

  10. #55
    Registered User
    Join Date
    Sep 2010
    Location
    Massachusetts
    Posts
    42
    I've been suggesting to both talents to put video make-up on both talents, but it hasn't yet happened hehe.

    I'm currently waiting for kino-flo to respond to an email I sent about True Match CFL bulbs (95 CRI, 5500K) that I found on their website but cannot yet find at any vendor. http://www.kinoflo.com/Kino%20Flo%20...ue%20Match.htm

    I think these would be ideal.

    Thanks for all the suggestions and help Brian.

  11. #56
    Registered User
    Join Date
    Apr 2008
    Location
    Burlington, ON
    Posts
    156
    If you are still interested in purchasing one of the DSC Front Box charts, you should ckeck out the DSC website and their August newsletter. They have a bundled sale available until Sept. 15th.

Page 4 of 4 FirstFirst ... 234

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •