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Thread: Flash Photography

  1. #1
    Boatman's Avatar
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    Flash Photography

    I have an Olympus FL36 to go with my GH2 camera and use it primarily for family event photography. Experimentation with this combination led me to believe that the best setting was to put the camera in iA mode and let the camera and the flash unit figure things out. Frequently I use a ceiling or 45 degree bounce. As a general rule this has worked.

    On Christmas we had a number of relatives over and I shot around a hundred photos. Among them are a number of photos with significant ghosting in the images. The metadata showed that these shots were taken at around 1/10 of a second with f1.7. The flash did fire. Many other shots, which did not have ghosting, were shot at 1/60th or 1/125th of a second, also at f1.7 with flash. The ISO was 160 for all the shots.

    Reflecting on this, I’m of the opinion that my problem may lie with the iA mode. iA mode disables all the settings on the camera. I did some experimentation with the camera in shutter-priority mode at 1/125 and the ISO bumped up to 640. Using either direct flash with the diffuser or with a 45 degree bounce yielded consistent exposure without significant harsh frontal lighting. The f-stop used (auto set by the camera) ranged from about 2.0 to 3.5.

    I am aware that the flash needs time to recycle, but I have good batteries and with decent ambient light, the flash will recharge within seconds. (Recognizing that this is very distance dependent – longer range shots use more light and increase the recycle time accordingly.)

    What suggestions do others have for successful flash photography? Are there other tips I should be aware of?

  2. #2

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    Re: Flash Photography

    ISO 160 and f/1.7 doesn't sound like the "iAuto" is particularly "intelligent", as the sensor performs well up to ISO 800. If you can set shutter and aperture manually and use TTL-flash, I'd suggest setting the aperture to 2.8 or 4 or there inbetween and shoot at ISO 800 with the bounced flash. The long exposures kick in when the flash is insufficient, so you might have to open up a little, but I think that would solve the problem.

  3. #3
    DeepWater's Avatar
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    Re: Flash Photography

    I am just learning flash myself, so am not an expert, but it occurs tome that perhaps your problem is your flash sync speed. You might check your cameras manual and see what your max sync speed, or what you had it set on. I also don't know the olmpus camera, so am not familiar with what iA means. I know that with a Nikon, if you want the flash and camera to figure exposure you need to be in Aperture priority mode. Not much help I know but perhaps someone with more experience can enlighten us both!

  4. #4

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    Re: Flash Photography

    There is a lot of information here but it does relate specifically to Canon.

    http://photonotes.org/articles/eos-flash/index.html

    Most of it should be similar though.

    And, of course, a couple of tutorials from CinC http://www.cambridgeincolour.com/tut...mera-flash.htm

    http://www.cambridgeincolour.com/tut...ra-flash-2.htm

    Personally, I manually set my camera to suit the scene (shutter speed, aperture and iso) then let the auto flash output control take care of the flash strength. With a little bit of flash output compensation as required.

    But be aware of any limitations such as max shutter speed.

    Somewhere around 1/200 F5 iso 200 would be typical for me. But it depends on the actual scene plus lens and ambient light.

    But this is with a different camera from what you have, Homer.
    Last edited by Geoff F; 27th December 2012 at 08:39 PM. Reason: links added

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    Re: Flash Photography

    I'm not an expert either, but I usually do what Geoff does: set the camera manually and let the E-TTL take care of itself. My standard starting settings for indoor candids are ISO 400, 1/60, f/4.5. This is using bounced flash with a bounce card (a Demb Flip-It) to direct a little light straight forward.

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    Moderator GrumpyDiver's Avatar
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    Re: Flash Photography

    You were inadvertently using a technique called "dragging the shutter". As you have locked your ISO to a fairly low value of 160, I assume your aperture is wide open at f/1.7, so the only adjustment that the camera could make was with shutter speed.

    Your flash fires at somewhere around 1/1000th of a second, yet your shutter was open for 1/10th sec, so the flash froze part of the scene and the "ghosting" comes from the camera or your subjects moving during the time the shutter was open while being illuminated by the ambient light in the room.

    The fact that you are using an Olympus flash with a Panasonic camera is possibly part of the the issue. I suspect that they will operate properly if you were shooting in manual mode, but the fact that you are trying to shoot in an automated mode could be problematic. Your flash was designed to work with the Olympus E series cameras, so there is no guarantee that it and your GH2 are compatible. If you think of your GH2 as a computer that takes pictures; a computer that comminicates with your lens (the mFT standard takes care of some compatibility issues here) and your flash (which does not have any standards other than the trigger voltage), you might better understand what might be happening here.

    Bounce flash is a good technique, but there are a lot of variable involved in the shooting. Distance to the surface you are bouncing from, reflectivity of the surface, etc. all come into play. We could probably do a better diagnosis if you posted some of your images. I rarely use just bounce lighting when taking shots of people; I use a reflector card on the flash to send some of the light directly the subjects and do general illumination with bounce. This brightens up the eyes (pure bounce can cast dark shadows) and adds catch lights to the eyes.

    One of my flashes has a built in white card, but before I had it I just attached a piece of white cardboard onto the flash with some rubber bands and it did the trick quite nicely.

    Flash Photography


    The other suggestion I would make to you is to learn how to use your flash on manual. That way you won't be second guessing what your camera is trying to do.

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    Re: Flash Photography

    Quote Originally Posted by DanK View Post
    I'm not an expert either, but I usually do what Geoff does: set the camera manually and let the E-TTL take care of itself. My standard starting settings for indoor candids are ISO 400, 1/60, f/4.5. This is using bounced flash with a bounce card (a Demb Flip-It) to direct a little light straight forward.
    I agree with the above. However, when you are shooting with a flash of a different brand than your camera, your camera may or may not recognize that you have a flash mounted and ready to fire. It will also very likely not be controlled with ETTL through the lens metering.

    Note: There are some flashes made by third parties such as Sigma, Metz, Sunpak and others which have different models (or modules) designed specifically for cartain brand cameras. These for our present purposes can be considered the same as OEM flash units. There are also some manufacurers who have basically joined in manufacturing cameras. lenses and flashes which can work with either manufacturer's gear.

    What has happened in your case however is that the camera is exposing for the ambient light alone which results in selection of a large f/stop (f/1.7) and a very slow shutter speed (1/10 second). Obviously, the flash and the camera are not talking to each other or cannot understand the others language since the flash is talking in the Olympus language and the camera understands the Panasonic language. This slow shutter speed allows subject movement or camera shake to blur the image. A secondary exposure from the flash is superimposed over the ambient light exposure to give you the ghost image.

    You can possibly use your Olympus flash with uour Panasonic camera by using each in the manual mode at somewhere about 1/60 or 1/125 second and determine the f/stop manually!
    Last edited by rpcrowe; 27th December 2012 at 10:18 PM.

  8. #8
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    Re: Flash Photography

    Thank you all for your comments and suggestions. There are some good ideas listed. I've attached two photos as examples of what I experienced Christmas. The ghosted image is not the worst of the batch, I had already discarded the really bad ones. The Olympus FL-36 is the same flash as the Panasonic FL-36. They are documented to be the same flash unit; the only difference is that the Panasonic version costs a good deal more. The flash and camera are well mated. I re-read my GH2 manual and the manual for the FL-36. There is a setting in the camera’s flash settings to allow shutter speeds below 1/60th of a second, down to one full second. Otherwise, in iA mode, the camera is supposed to be limited to speeds above 1/60th. I figured this had to be the issue, but a check of the camera showed that I have the setting correct. I took a bunch of random shots this evening to see if I could re-create the sub 1/60th shots and failed to do so. When testing in iA mode nearly every shot is 1/60 or 1/125. I messed around more in shutter-priority and full manual to see how those settings worked. Using roughly f-3, 1/125 and ISO640 seems fine though sometimes the flash strength has to be dial up or down a bit if the subject is particularly dark or bright.


    As Inkanyazi noted, f1.7/ISO160 is hardly ideal with this camera - especially when I’m taking family photos that will never see enlargement beyond a 4x6 print or a standard computer monitor. I had previously experimented using some old manual primes with the FL-36 flash and found that putting the camera in full manual mode and using the TTL-Auto mode in the flash yielded perfect exposures. I also noted at that time that using a fast f-stop and ISO1200 would allow the flash to recycle in less than a second. Given that the FL-36 is famous for slow recycling, this was a bit of a revelation, but I see what is going on. By using the fast ISO and f-stop, the flash hardly has to work at all; it’s just fill flash to the ambient room light. As a result it does not fully discharge its capacitor and therefore recharges much faster.


    In my test shots today I noticed something new and useful in the settings for TTL-Auto and 'plain' Auto. When the camera is in iA mode, the flash will only operate in TTL-Auto mode. When the camera is in shutter-priority or full-manual (and I suppose aperture-priority, too), the flash will operate in TTL-Auto, 'plain' Auto or Manual modes. Using the TTL-Auto mode, the recycle time for a typical indoor 12' shot is about seven seconds. By changing the flash mode to Auto, no other changes to the camera settings, the recycle time drops to under three seconds. With a subject at 7', in Auto mode, I was able to shoot 15 shots before I had to wait more than a second to fire off the next shot. Clearly the TTL pre-fire and measurement is using a lot of flash's power. (Auto mode does not use a pre-flash for exposure correction, it is done in the camera and relayed to the flash.) I read through the GH2 manual, the Olympus FL-36 manual and the Panasonic FL-36 manual. None of these documents has any useful information about how the TTL-Auto and 'plain' Auto actually communicate with the camera, so I can't explain exactly what is happening.

    It appears to me that my thinking on iA mode is wrong. I'm better off in manual or shutter-priority mode and with the flash in the Auto mode, not TTL-Auto. I read several of the documents suggested and I will need to learn more about flash ratio, FEC and EC settings. Also, I need to go to more parties and take more indoor photos. Nothing like more practice to perfect your techniques!

    Ghosted Image, 1/8th second exposure
    Flash Photography

    Non-Ghosted Image, 1/125th second exposure
    Flash Photography

  9. #9
    William W's Avatar
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    Re: Flash Photography

    It occurs to me that there is a difference in the FLASH UNIT’s SETTINGS of those two images and this is confirmed by the EXIF.

    The (ghosting) First image’s EXIF records: “Flash Fired - Auto Mode”
    The (no ghosting) Second Image’s EXIF records: ”Flash Fired – Compulsory Flash Mode”

    The EXIF indicates that the CAMERA MODES for both images are the same.

    Therefore, it would seem logical to assume that in the two minutes between the two images being made - you either CHANGED the Flash Functionality OR the Flash’s Functionality was changed automatically.
    If the former is not true – then again, the most logical first guess is that the Flash Functionality was changed by a the FULL Recycle NOT completed - or the Unit has an intermittent fault.

    I suggest you follow the line of investigating the Flash Mode being used and confirm that a FULL recycle has taken place.

    WW

  10. #10

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    Re: Flash Photography

    Personally I would use the GH2's own onboard flash for family fun shots ... if people were going to be looking at the camera I might choose red-eye flash mode. The flash is so close to the lens that the harsh shadows of a flash on hot shoe are unlikely to be disturbing. One can try to be too good and foul up. The GH2 can also go to 12800 ISO and unless one is particularly allergic to noise ambient light will produce natural results for computer size images if you shoot tightly. Better noise than ghosting?

  11. #11
    Boatman's Avatar
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    Re: Flash Photography

    Flash Answers

    I found a very good article explaining TTL-Auto and ‘plain’ Auto flash modes at http://dpanswers.com/content/genrc_flash.php. I also read the CiC article Camera Flash: Exposure carefully. Tonight I reviewed my photos from Christmas and did a lot of documented testing with the flash and camera.

    First, I pulled all my discarded photos out of the trash and restored them to Lightroom. Using the time data I was able to see that the exposures with less than 1/60th of a second occurred when I was rapid-fire shooting. I always wait for the ready light, but this apparently is not accurate - more on this to come. In some cases a full flash would occur in under four seconds, in others a partial flash would occur after ten seconds. The slow shutter speeds were not 100% consistent with the time interval, but in all cases the bad shots are close together in time.

    The GH2 user's manual is pretty clear about the iA mode not shooting at a speed under 1/60th unless the slow-flash setting is on, which it was not. However, this is for the on-camera flash. The manual is unclear exactly how it handles external flash. It says nothing about what happens if the flash is not fully charged.

    Testing the camera I discovered several things:

    - Giving the flash plenty of time to recycle, in iA mode the camera will normally expose at f1.7, 1/125 and ISO160. You cannot change these settings. The shutter speed will occasionally drop to 1/60.

    - If you fire immediately after the ready light comes on in iA mode you have about a 50/50 chance of getting a sub 1/60 second exposure. If you wait two seconds after the light illuminates, you will get a 1/60 or 1/125 shutter speed.

    I think this fully explains the results I got on Christmas. I was shooting quickly and intentionally shooting immediately after the ready light came on. This is a bad practice with this camera using these settings. I went on to explore what other options might work better.

    First I switched the flash from TTL-Auto to Auto. Using this settin,g the delay between the shot and the ready light coming back on is momentary at most. Shooting with a 45 degree bounce on an item about 7' away, you can essentially take a shot every second until your batteries run out or the flash overheats. (I didn't prove either.) The shutter speed in 16 shots was 14 at 1/60 and two at 1/125.

    I went on and tested with P-program, S-shutter priority and M-manual modes. P does not give any significant advantages as it balances aperture and speed off of the base EV. You cannot set the shutter speed above 160 with a flash. S mode works very well. Set your shutter for somewhere between 1/60 and 1/160 and fire away. In most cases, the camera will pick f1.7 for the aperture and balance the image with the flash. I then tested manual mode. This, as Inkanyezi suggested, seems to work best. I took about a hundred test shots and compared the results:

    The information is laid out as - Flash Mode > Camera Mode > f-stop/speed/ISO > comments

    These shots were all shooting a common image, a chair with a jacket, located about 7 feet away using a 45 degree bounce flash.

    TTL-Auto > iA > 1.7/125/160 > not reliable, flash frequently fails to recharge fully. The flash will not go off until the ready light is on (thought the camera will take a picture) but shooting as soon as the ready light came on resulted in about 30% of the shots being under 1/60.

    Auto > iA > 1.7/60/160 > better as flash cycling is shortened to a couple of seconds (Note that earlier I said that you could not select this mode in iA, but in fact, you can.) No shots under 1/60.

    TTL-Auto > P mode > 2.8/60/320 > you can't actually set the speed in this mode with an external flash, but all the images came out 1/60. Exposures all good.

    TTL-Auto > S mode > f?/125/320 > images show f is being set to 1.7, recycle time is down to about two seconds. Exposures all good.

    Auto > S mode > f?/125/320 > images show f is being set to 1.7, recycle time is essentially zero. You can shoot a frame a second indefinitely. Exposures all good.

    Auto > M mode > 2.8/100/320 > 0 to 2 seconds for the ready light, but shooting as soon as it is on does not create any issues. Exposures all good.

    Auto > M mode > 5.6/100/320 > 5 seconds for the ready light, but shooting as soon as it is on does not create any issues. The images all look good but the histogram shows slight underexposure.

    Auto > M mode > 5.6/100/320 > flash +1EV > cycle time is up to 5-7 seconds. The images all look overexposed but the histogram does not go off the right end of the scale.

    The next results are from random shots taken in a moderately well lit living room at night. Distances ranged from 2 feet to about 15 feet. Again, a 45 degree bounce flash was used. I put in fresh Maha Immedion batteries at this point, though the other pair did not seem weak yet. An ambient room light exposure required 1.7/15/320, which is 3.5 stops under the exposure with flash of 2.8/60/320.

    Auto > M mode > 2.8/60/320 > images all look slightly over exposed, flash recycle time is negligible unless shooting all the way across the room, in which case it increases to about 3 seconds.

    Auto > M mode > 2.8/60/320 > flash -1EV > images look slightly under exposed, flash recycle time is negligible.

    TTL-Auto > M mode > 2.8/60/320 > images look good but the flash recycle time ranges from 5 seconds for close object to over ten seconds with objects across the room.

    So there it is. iA mode with external flash is NOT the way to go with a Panasonic GH2 camera. Also, I don't see any benefit in using the TTL-Auto feature of the flash unit as the Auto mode works just as well, cycles much faster and probably extends the battery life. From now on, I'll use manual mode and put some thought into what my ambient light requirements really are and how much flash I'll need to dial in to get things balanced. It's a bit more complicated than just putting the camera in iA and blasting away, but hey, the results are so much better than with flash bulbs!
    Last edited by Boatman; 29th December 2012 at 01:34 PM.

  12. #12
    William W's Avatar
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    Re: Flash Photography

    You learnt a great deal, well done.

    Quote Originally Posted by Boatman View Post
    . . . From now on, I'll use manual mode and put some thought into what my ambient light requirements really are and how much flash I'll need to dial in to get things balanced. . .
    Think about the ISO, also.
    ISO has the major governance of the Recycle Time in many shooting scenarios.

    WW

  13. #13
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    Re: Flash Photography

    Yes, I agree. I think f3.2,1/100 and ISO620 may be just about right with a little flash adjustment up or down. But as alway - it depends! At least now I have some idea of what I am doing

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    Re: Flash Photography

    Quote Originally Posted by GrumpyDiver;274738dark shadows)
    [url=http://www.flickr.com/photos/52469432@N05/8316218940/
    Flash Photography[/url]


    .
    With regard to the photo I would suggest the white card is superior, I use the bottom of a plastic icecream container. but beware of using the flash tilted forward as in the photo because there is a danger of light coming directly from the unit and lighting at a brighter level the top part of the photo.
    Further to my earlier comment it could be worth checking out the 'light scoop' or 'litescoop' since the onboard flash is quite powerful ...I did this with my FZ50 and a bit of builders aluminium paper/foil and it would have worked well but for the yellow ceiling in my room.
    Last edited by jcuknz; 29th December 2012 at 07:51 PM.

  15. #15
    William W's Avatar
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    Re: Flash Photography

    Quote Originally Posted by Boatman View Post
    Yes, I agree. I think f3.2,1/100 and ISO620 may be just about right with a little flash adjustment up or down.
    For Flash Candids on the hop at Functions I tend to start at ISO800 , and I have bigger flashes - but I want a very quick re-cycle - I think you are in the ballpark at ISO620 (640?)

    WW

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