Flash exposure

Why does a frame exposed with a flash flicker? What can be done about it if you want to increase its duration?

The flickering is an artifact of the interlaced nature of video. It is a result of very thin (often horizontal) elements that exist on one scanline as is common in text or titling. This can also be the case in images with great deal of detail with high contrast.
As the alternate fields play, the flashing element is essentially being turned on/off. The basic strategy is to get the element to exist over two scanlines so it is refreshed every time the field plays and/or to reduce the amount of contrast so the difference between ON and OFF is not so noticeable.
Things to try (In increasing order of image degradation)
- (in FCP) field order>none
- (in FCP or Photoshop) reduce whites by 10% - reduces overly bright areas. You can also work to reduce areas of very high contrast.
- (in FCP) flicker filter - minimum
- (in Photoshop) motion blur>vertical> .2 - .5 pixels - blurs vertically only
- (In FCP or Photoshop) Gaussian blur> .2 - .5 pixels -blurs both horizontally as well as vertically
- (in FCP or Photoshop) deinterlace - throws away half the image and is generally not appropriate on scanned images
Remember: Unless you are viewing your work in the appropriate external NTSC/PAL monitor, you are playing blind. The computer monitor only shows you a half resolution proxy image.
good luck.
x

Similar Messages

  • Problem Viewing Flash Exposure Data in Bridge

    Hi Folks
    When I view flash exposure data on my camera it will show me the flash compensation value I have set eg -0.7 or +2. When I download the images and view the metadata in Adobe Bridge (from CS3) I appear to lose this information. It will tell me that the flash fired or nor, but that is about it!
    Is there anything I am missing here, or is it just a limitation of Adobe Bridge.
    Any information would be gratefully received.
    Regards

    I have been looking for the same information in CS5. Although I can't find it displayed anywhere in the Camera Data you can find it if you really need to.
    Choose File Info from the File menu and then go to the Raw Data tab. Use the search function to look for "FlashCompensation". I found it there for my Canon G11.
    Painful but works if you really need it too.

  • Flash Exposure Compensation Metadata

    Please allow Bridge to read and state the degree of Flash Exposure Compensation that a photo uses in its metadata. Currently, Bridge does not read this info for Canon photos but the info is in the picture.

    Yes, yes and yes. Its a good thing I kept Breezebrowser

  • Flash Exposure Compensation Value Not Displaying in EXIF Info

    When adjusting Flash Exposure Compensation on Nikon D4 camera (not on the Speedlight) the set value is not showing in EXIF Field in Aperture 3.4.1.  It always shows as a 0 value regardless of camera setting.  When I open the .nef  in Nikon View NX (v2.2.4) the set value for Flash Exposure Compensation is accurately shown in the EXIF info.  Have tried editing the Aperture EXIF fields (removing Flash Exp Comp and re-entering it) but, to no avail. Has anyone seen this, or  know of a solution?  Are any D800 users seeing the same thing?
    Thanks!

    Greg,
    All the references to the element "rdf:value" in the XMP Specification 
    Part 1 appear in discussions about the implementation of XMP Qualifiers.
    Page 21,
    The presence of property qualifiers is indicated by a special use of 
    the rdf:Description element. Each rdf:li array item in the example 
    contains an rdf:Description element, which itself contains the 
    following:
    --  a special element called rdf:value that represents the value of 
    the property
    -- zero or more other elements that represent qualifiers of the value. 
    In this case, there is one property qualifier called ns:role.
    Page 26
    Other qualifiers cause the RDF for the qualified property to look like 
    a struct with a special rdf:value field. The presence of rdf:value is 
    what denotes this as a qualified property.
    Page 28
    For qualifiers other than xml:lang, RDF forces the qualified property 
    to look like a struct with a special rdf:value field that contains the 
    actual value from the XMP Data Model. The other fields of the fake 
    struct are the qualifiers. The presence of rdf:value is what 
    distinguishes a real struct from a qualified property.
    I assume that you are not trying to implement XMP qualifiers. Perhaps 
    you should use vra:value instead?
    Carl Rambert, Pound Hill Software

  • Flash exposure correction not show in Aperture 2 metadata view??

    When using the nikon SB-600 flash exposure correction the information is stored in the NEF/RAW file, a read back in Nikon' View NX sofware is correct. However the read back in Apple' Aperture is always set to 0ev (which is not correct).
    Any suggestion how to obtain the correct metadata? Use a plugin?

    When using the nikon SB-600 flash exposure correction the information is stored in the NEF/RAW file, a read back in Nikon' View NX sofware is correct. However the read back in Apple' Aperture is always set to 0ev (which is not correct).
    Any suggestion how to obtain the correct metadata? Use a plugin?

  • 600EX Flash - 5D III. Flash exposure compensation.

    How can I set the FLASH exposure compensation from the CAMERA. It appears that I have to set the exposure compensation on the back of the flash unit. I would like be able to change the FLASH EC settings from the camera, not the flash unit.
    Solved!
    Go to Solution.

    Ok, I have my 5D III out with my 600EX-RT mounted.
    Let's make sure you don't have terminology confused.
    There are two different compensations... there's "explosure compensation" and "flash exposure compensation".
    If you meter exposure with the camera and then use the rear dial (assuming you did not disable it) after waking up the metering system then the rear dial will change the "exposure" compensation (this changes the metering for the AMBIENT light reading that the camera reads -- ignoring the flash).  So changing "exposure compensation" will not change the flash even if the flash is powered on and connected.  It would only change the camera.
    On the top of the camera, just in front of the top LCD screen, there are four buttons.  One has a dimple on it.  That button is the ISO & "flash exposure compensation" button.  If you press that button, then the rear LCD screen should show you that the rear dial will control "Flash exposure comp."    Turning the rear dial at that point will make the adjustment show initially ONLY on the camera LCD screen... UNTIL you press the 'Set' button in the middle of the dial.   Once you do that, the rear LCD screen on the flash will show that you have the flash exposure compensation enabled (it will ONLY show this when you wake up the metering system... if the metering system is allowed to go inactive the flash will only display the netural compensation... but as soon as you re-activate metering it will display your exposure compenation as set on the camera.
    Also... on the rear LCD screen there's a box just below the ISO setting that shows if you have flash exposure compensation set and the amount.
    This is all being controlled only by the camera -- I'm not using the menu buttons on the flash itself.  
    IF I DO use the buttons on the flash to set flash exposure compensation then the camera is locked out.  It will report what compensation has been set on the flash, but will not let me change it until I use the buttons on the flash to return it to 0.
    Does that help and are you able to do this with your flash?
    Tim Campbell
    5D II, 5D III, 60Da

  • Flash Exposure Compensation

    I am shooting RAW files with a Nikon D200 and SB-800 Flash. I use controls on SB-800 to adjust flash exposure compensation. When photos are imported into Aperture the flash metadata states "strobe return light detected". The flash exposure compensation field lists zero despite having set an exposure compensation on the flash. Any ideas?

    Yes, yes and yes. Its a good thing I kept Breezebrowser

  • How to unlock a Flash Exposure Lock?

    My 5D Mark II is set in Manual Mode with an attached Speedlite (580EX II).  I've set the manual settings to 1/400-F8 for an outdoor portrait.  When I depress the shutter release the settings switch to 1/200-F8 and record the image. Overexposed. 
    If I fire off 6-8 images, the camera will record 4 or 5 images at 1/200-F8, then it will record 2-4 images at 1/400-F8.
    I have already examined every menu function and tried (unsuccessfully) to reset the camera's settings.
    Does anyone have any explanation that could help me solve this issue.
    Thank you,
    Jim

    1/200th is the camera's max "flash sync" speed. You can't take an exposure faster UNLESS you enable high-speed sync ,ode on your 580 Speedlite. Keep in mind that high speed sync causes the flash to pulse light rapidly as the shutter sweeps across the sensor. That means the flash can't fire at full power because it needs to conserve enough power in the capacitors to be able to use the required number of pulses. E.g. If it has to pulse 4 times than no single pulse can use more than 1/4 of the power. You can cluster multiple speedlights to get around that problem.
    Tim Campbell
    5D II, 5D III, 60Da

  • More consistent ETTL II flash exposure with 580exII or 430exII

    Canon stated that the ETTL II is designed to treat the exposure as a "plane" and not as "point" to correct the inconsistent exposures due to various reflections.
    When I shoot in large, dark room,  the subjects at the front rows are well exposed, however the 2nd row subjects, only inches behind, are underexposed by 1-11/2 fstop. Is this a calibrating sync issue ?
    I used the 17-40mm f4 and 70-200mm f4 IS which have "distance infomation" incorporated into the ETTL II to prevent overexposure. Is it possible that this feature was over compensated? I have sent in for calibration several times already, why is it not fixed?
    Does the 6D or 5DmkIII have different design in ETTL II flash?
    I have tried to vary  the "evaluative" meter,  the "average" meter, AV mode, Tv mode, Manual mode  which doesn't seem to make a different in consistency. I noticed that some other cameras have spot meter for flash, and tend to have much brighter background than my 5DmkII at the same camera setting.  I can try to use the flash memory lock which sometimes can not afford the added steps.
    Thanks for your comments.

    Welcome to the Inverse Square Law. This video should answer your question.
    http://www.youtube.com/watch?v=f5BIvSBjvLg
    Website

  • Flash Exposure Bracketing T3i

    Hi, I am new to Canon and this is my first post.  I just got the T3i and believe it is not possible to do FEB with the built in flash.  Am I correct on that?  The direction to do that is with an external speedlite flash.  Which Speedlite model does FEB, and works best with the T3i?  Plus I like to use bounce flash too.
    Thanks
    CX

    Copperxray,
    I am sorry, but FEB is not available when using the built-in flash.  You will need to use an external Speedlite flash, such as the Speedlite 600EX-RT or the Speedlite 430EX II.  Both of these allow you to do bounch flash as well.
    If this is a time sensitive-matter, additional support options are available at Contact Us.
    Did this answer your question? Please click the Accept as Solution button so that others may find the answer as well.

  • EXIF data - e.g., Flash Exposure Compensation - is it hidden someplace?

    I see in LR various pieces of EXIF data, but can't find FEC. Is it hidden someplace? Thanks.

    Rob, this looks very good! Would any possible bugs in the code be limited to problems in searching on or viewing metadata, or does it have the potential of corrupting the LR database itself? From my limited understanding of the internals of how LR works, it seems to me that plugins would not be able to damage the LR database. Thanks!

  • Standardizing exposure across multiple images using a gray card

    Hi,
    I am studying chest feather coloration in Barn Swallows, and take pictures of swallow chests against a white background with gridlines, while always including a gray card in the image. In order to evaluate chest color between birds, the lighting, exposure and white balance for all images must be identical.
    I place my tripod in the shade whenever possible and set exposure manually (using the spot meter on a D200) to be 2 stops underexposed, and use fill flash to provide the bulk of the light. This gives me even lighting, but because of the automative flash exposure adjustment, each photo has slightly different luminance.
    I was under the impression that adjusting exposure would be a snap by clicking on the gray card in each image and telling my software to adjust it to 18% reflectance. However, Lightroom does not seem have such a feature. This seems very strange given how frequently one is instructed to standardize exposure with a gray card.
    Adding to the problem is that my gray card (from Delta) has a lot of microscopic variation in its surface in brightness (and hue). While Lightroom gives me a white balance adjustment eye dropper, it seems to be limited to sampling one pixel, rather than averaging values over a number of pixels. Because of the limitations of my gray card, Lightroom's white balance eye dropper is of little use, as the white balance vary dramatically depending on which pixel on the gray card I sample. Is there a way to change the size of the area sampled for white balance purposes?
    Thanks much,
    Gernot

    Gernot,
    I think the thing to do is to use a consistent setup, which means no TTL on the flash and a set distance from the subject, and minimise ambient light effects (small aperture).
    Alternatively you could photograph a "colourchecker" with each bird and use a calibration script on the raw files to sort out the settings each time - a bit lengthy though, expect about 20 minutes a time. However, it would be quite definitive.
    As far as the "single point" problem goes, you could set all the noise sliders to the max to blur out the imperfections in the card, take a sample, then undo the noise corrections.
    I can't help thinking that for reference work like this, Photoshop is the tool for the job and LR will help you get organised into PS, but it won't replace it.
    Damian

  • Canon 5D3 Feature Request / Wish -- Manual exposure auto shutter speed toggle

    I've been using Canon gear the last six years & I don't know if this is currently possible in any camera body. If not, I believe it would prove highly helpful for working professionals.
    When working in time-sensitive situations, I find myself frequently forced to use Av mode when I would prefer to remain in Manual exposure. Additionally, I find myself slowed down within Manual exposure mode when moving between inddor and outdoor light and/or other situations of dramatic ambient light fluctuation.
    My wish would be for a menu assignment function for the "multi-function" button (next to the shutter release). Pressing the button while in M exposure mode would then set the shutter speed (like in Av mode--and another option could emulate Tv mode), and releasing the button would resume normal M exposure mode usage.
    Personally, this is my biggest wish for the 5D3, and I would LOVE to see it implemented. (My second wish would be for the flash exposure lock to set the exposure of Flashes which are otherwise set to manual flash exposure, but that's another story).
    Thanks,
    Bert

    Nope. That's a 1D X feature.

  • HDR w flash

    1) Nikon D-200; 105 mm lens; SB-600 speed flash in combination with a lens mounted ring flash.
    2) Nikon is mounted on a rack and pinion stand with rotating head.
    3) Sample is a highly reflective metal sample exhibiting small cracks and some corrosion.
    4) Camera focus, aperture, iso setting and shutter speed remain fixed; stops adjusted using flash exposure.
    The reflectivity of the metallic sample makes image capture of surface structure, small cracks and limited areas of corrosion difficult to capture. Seemed like a good option for Photoshop HDR capability.  Have tried bracketed series involving 3 to 11 images.  Histograms suggest the dynamic range is being covered by the image series.  Photoshop reports there is not sufficient dynamic range to build an HDR image.
    I read somewhere that Photoshop uses EXIF info when building HDR images.  Are the fixed camera settings keeping Photoshop from building an HDR image?  Should I be looking at something else?
    Some sample histograms randomly selected from cropped thumbnail versions of an image series.  I've pushed as far as two stops on either side of the samples shown here (almost all black and almost completely white but Photoshop indicates there is insufficient dynamic range to build HDR in all instances).

    Here's the link to the Photoshop Macintosh and Windows forums:
    http://forums.adobe.com/community/photoshop/photoshop_macintosh#
    http://forums.adobe.com/community/photoshop/photoshop_windows

  • Match Total Exposure Not Working For Me

    I am taking several pictures (sometimes 100s) of the same object in a studio setting.  I have all of the camera controls locked down in manual mode so things like ISO, aperture, and shutter speed are uniform across the entire shoot.  I am also using flash for external lighting.  My problem arises because the flash will produce different levels of light from shot to shot (despite being in manual mode) so the pictures have different lighting levels - some are brighter than others.
    Is there any way to batch process these photos to have a uniform level of light?  It seems as though the Match Total Exposure feature creates no change at all.  Is that because the ISO, aperture etc. is the same in all the pictures?  I need a way to correct for the fluctuating light output of the flash.

    >Is that because the ISO, aperture etc. is the same in all the pictures
    Yes. That is exactly what "Match exposures" does. It looks at ISO, aperture, and shutter and corrects to get to the same EV. If all your images were shot at the same settings, they can't be corrected this way. This is not the way to do consistent flash exposure BTW. You should be correcting either flash output or aperture based on distance (or ISO if you don't want to change aperture or flash intensity) as the intensity of light on your subject decreases inverse square law with distance. Most camera systems can do this automatically based on focus distance and some through the lens flash metering but it is possible to do this manually too. If your flash is off camera (e.g. shooting through an umbrella or bouncing on a ceiling or somesuch) you often don't need to do this and you can stay at one exposure since the distance of the flash to your subject generally doesn't change and so amount of light on the subject doesn't vary.
    > I need a way to correct for the fluctuating light output of the flash.
    Can't be done easily in Lightroom. The only way is manually correcting visually. It is almost impossible to automate something like this although I guess you could generate some scripts in Photoshop that looks for common tones (like flesh tones) and equalize them. Not at all trivial though and very much a highly advanced thing to try. Your best bet is manual exposure compensation. Should be very quick. Just arrow through and correct either in quick develop with a few clicks or in Develop.

Maybe you are looking for