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Before The Coffee » Photography
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The maximum flash sync speed for the A7r is 1/160 sec and for the A7 it is 1/250 sec. Above those speeds is High Speed Sync territory. For a explanation of High Speed Sync scroll to the bottom of this post and read: “An explanation of High Speed Sync.” NOTE: I use White Lightning studio strobes and Nikon SB-800‘s with Pocket wizards so HSS is definitely not possible. However, the Sony HVL-F43M and 60M both have HSS so it should be possible with the A7(R). I’ve also heard that the Metz 52 AF-1 for Sony will also work in HSS Mode. Also, wireless with a small HVL-F20M on the hotshoe and a Metz remote will also work. The Metz 52 AF-1 is worth a look for the price and quality. WHY would I want to use High Speed Sync?  This image has no fill flash, exposure is for the sky while shooting into the sun. F/22 (for the star burst), 1/250, ISO100. Let’s say for example I want to take a picture outside and I want fill flash on the subject AND the sky nicely exposed. If I expose the sky properly I might need: f5.6 @ 1/800 ISO 100. My flash cannot work at 1/800 unless I have high speed sync ability. So my alternative without high speed sync is to shoot at f5.6 @ 1/160 ISO 100 but overexpose the sky more than 2 stops. The dynamic range of the A7R is so incredible that this setup can work but may push the limits of good techniques in post processing. What are my options if I have a flash without high speed sync abilities:
This posts explores number 5 with the Sony A7R. How much can I exceed the maximum flash sync speed and still get useful images? I worked with a rock band recently and we planned a sunset shoot. While we waited for sunset I did some test shots that exceeded the maximum sync speed of 1/160 second. I also took some studio shots of a backdrop with a scale marking 0-100% from top to bottom. When the shutter exceeds the maximum sync speed the top of the image becomes blocked by the flash exposure and the percentage can be read off easily. Conclusions with the A7r: NOTE: A flash image really consists of two exposures, one of flash that falls on the subject and one of ambient light. During “normal” flash photography (not HSS) the f-stop controls the flash power and the shutter speed controls the ambient. Why? Remember that the flash duration is very fast, 1/4000 sec for example, so a shutter speed of 1/40, 1/60 or 1/160 will not have an impact on how the flash lights the subject, but it will impact the ambient exposure. However, when in High Speed Sync the shutter speed does influence the flash exposure.  The maximum sync speed of the A7R is 1/160 second. Here you can see that the shutter does not interfere with flash exposure. At a sync speed of 1/200 second there is a minor impact at the top of the image. The slight darkness can be corrected in post-production.
At a sync speed of 1/250 second the top 10-20% of the image is blocked from flash exposure. At 1/250 second you can see the subjects are well within the area of flash exposure.
At a sync speed of 1/320 second the top 40% of the image is blocked from flash exposure. At 1/320 second you can begin to see the top 50% area is slightly impacted by loss of flash exposure. This could be corrected in post processing.
At a sync speed of 1/400 second the top 60% of the image is blocked from flash exposure. 1/400 second lacks flash exposure at the top 60% of the image. This is only useful when it’s carefully planned as part of the composition. Obviously this is not a successful setup for this shot. Final image taken at sunset. f10, 1/200 second, ISO 400 with fill flash. About 2 weeks later the band added another musician so we did a retake. I thought this was a cool shot for a band named, “Sky Came Burning.”
An explanation of High Speed Sync You can think of it this way. Imagine you’re sitting in the seats of a theater waiting for the show to start. The show begins and Curtain Man A opens the curtain from left to right. He pushes the curtain open but you cannot or would not want to take a picture until he reaches the other side. Curtain Man B closes his curtain and he also moves from left to right but he’s pulling a different curtain closed. If Curtain Man A gets to the other side and Curtain Man B waits before closing his curtain, then you have a clear shot of the entire stage. At the moment your picture is taken Curtain Man A and B are at opposite sides of the stage and your flash pops (1/4000sec.) and you get a picture of the entire stage. This is your camera at sync speeds slower than 1/160 sec. If Curtain man B leaves precisely when Curtain Man A arrives to the other side then at that precise moment a clear shot is obtainable. A fraction of a second before or after that moment either A or B respectively is blocking the stage with their curtain. That is the maximum sync speed of 1/160 second. Curtain Man A starts and 1/160 sec later he arrives at the other side, then immediately Curtain Man B begins closing. If Curtain man B leaves BEFORE Curtain man A gets to the other side then your single flash exposure will not get a full shot of the stage. The sooner Curtain Man B begins his walk pulling the curtain across the stage, the more the stage will be blocked. Remember you cannot take your picture until Curtain Man A reaches the other side. So your picture will be a portion of the right side of the stage. These are sync speeds faster than 1/160 sec. So how is high speed sync possible? Well it’s possible if the flash pop’s on and off very fast. In this scenario, you take the picture and Curtain Man A leaves the left side. Right behind him Curtain Man B begins his walk too. While Curtain Man A and B are walking across the stage there is a small gap between the curtains to view the stage. During their walk, your flash is popping the entire time, exposing the stage as they walk along….1/4000, 1/4000, 1/4000, 1/4000….. The flash continues to pop until Curtain Man A reaches the other side. The continuous popping of your flash allows you to expose the image with flash while using shutter speeds of 1/500, 1/800, 1/1600, even 1/3200 etc.
This is taken at f/16, 1/1250sec with the D3, single camera strobe full power. With HSS as the shutter speed increases the power of the flash has to increase, or get closer to the subject. I shot at f/16 for the star look in the sun.
Placing an ND filter on the lens and shooting a long exposure can give a nice moody feel. The technique is to shoot in normal daylight with ND filters and long shutter speeds. The Sony A7R has gotten a lot of attention for light leaks that take place around the bayonet – where the chrome ring contacts the anodized orange ring. http://www.dpreview.com/forums/post/53072154 I started with black electrical tape and recently discovered a hair tie (elastics) to be an easy, non-sticky alternative. It’s easy to carry in any camera bag too. Get the Goody variety because it does not have the metal connector and “it will give you the hold you need and the comfort you crave.” They are available at drug stores or online. They are the perfect diameter to stretch around the lens and fit snugly at the joint between the lens and body. Even if you catch them with your fingers while handling the camera they snap back into the groove. Also, it’s easy enough to leave on to cut down on moisture and dust and the possibility that “normal” exposures might be effected by a light leak. The biggest bonus is that it’s NOT unattractive! Goody hair tie around lens bayonet. Light leak present in upper right and left side. 30 seconds, f/2.8, ISO 25600. Exposure made within 3 inches of 60W incandescent bulb. Performing the same test with the Goody hair tie in place. No light leaks. Light Leaks with Studio Strobe (added 5/5/14) VIDEO of the Light Leak in the studio: https://www.youtube.com/watch?v=cbq_zXK3o0c
Light leak with camera near strobe. Strobe was placed lower left of camera. Settings: 1/60sec. ISO800, f/2.8.
Note: Numbers in parentheses refer to Menu tab and window within that tab, i.e.. Custom Key Settings(26) is the Second tab and 6th window in that tab. AF dominant setups: If your primary shooting preference is Auto Focus, change the AF/MF Button to TOGGLE in the Custom Key Settings(26). You will remain in AF and in the rare instance you want to use Manual Focus you just press and release the AF/MF button. It will stay in MF until you press the button again. I suggest turning on focus peaking as an alert that it’s in MF. If the camera is turned off, the next time you power up the setting will be AF. This is the setting that I use most of the time, it is easy to move to MF when I find AF isn’t up to the task. If you set AF/MF Button to HOLD in the custom Key settings then for the occasional MF you will need to hold down the AF/MF button while pressing the shutter release – a little bit awkward but doable with some practice. If you release the AF/MF button then follow with a half press of the shutter, AF will be reinitiated and your manual focus efforts will be gone. Setting the Focus Mode(12) to DMF (Direct Manual Focus). This will allow you to stay in AF and then if you decide to use MF then all you have to do is turn the lens focus ring while half pressing the shutter button. If you use DMF I suggest setting the Focus Magnif. Time(21) to 2 seconds. If you use No Limit then you will need to take the picture while in magnify view. Not really a bad way to work but takes a little getting used to. DMF Pros: Using MF is a fluid action and doesn’t require pressing buttons. Simply turn the focus ring and activate MF. DMF shows focus peaking while in Auto Focus. DMF Cons: It’s not good for tweaking or confirming AF – turning the focus ring activates MF and the magnifier but also changes any AF settings. Once MF is complete in magnify view it takes 2 seconds to return to full view. This can be too long or too short depending on the circumstances. It would be nice if a release of the half-press instantly returned to full view and a repress within say 2 seconds would keep the MF setting just achieved. It would give the user full control in timing the on/off of the magnify function. MF dominant setups: If your primary shooting preference is MF with intermittent use of AF, first change the Focus Mode to MF, then you can change AF/MF Button to HOLD or TOGGLE in the Custom Key Settings(26). HOLD is good because it allows you to press the AF/MF button and achieve AF without touching the shutter button. You won’t accidentally leave it in AF too. The only problem with HOLD is you cannot move the flexible spot AF area – it’s stuck where you placed it. You’ll have to get out of Hold, go to Toggle in the Custom Key Settings(26), then move the AF area. If you are ok with AF spot position always being fixed, (centered for example) you’ll get along fine with this setup. This is my preference for MF, it’s just a quick blip of the button, then back again. TOGGLE will give you control of the flexible spot areas for AF that HOLD does not. However, when you TOGGLE to AF you’ll have to follow with a half-press of the shutter to achieve AF. A little more cumbersome. When the camera is turned off it will revert back to MF. When should you turn AF w/ shutter OFF(24)? That means a half-press of the shutter will not initiate AF. You really don’t need to turn this feature to OFF. Even when it is ON when the camera is in MF it is off. Continuous Focus and Continuous Shooting This is the ideal setup for action shooting except things are a bit difficult with the A7R. The A7R does not have electronic first curtain – something that has been discussed at length in the forums with many pleas to Sony to release a firmware update. The challenge with the A7R is the EVF goes black at the start of the first frame making it difficult to maintain the Flexible spot focus on the moving subject. It’s like juggling and someone momentarily turns the lights off. A second option is to turn on AF tracking. This allows the camera to attempt to track the subject. I’ve not fully tested the reliability of this feature but in general I’ve found them to be hit or miss. Much like most “Auto” camera features, Exposure, AWB, Flash etc. they do not always do what you want. This is a vertorama taken with the A7R and the 35mm f/2.8. Manual focus on the rocks jetty in the distance for the top image and on the shells in the foreground for the bottom image. Both images taken at f/8.0 – a very sharp range for this lens.
Without reflection, we go blindly on our way, creating more unintended consequences, and failing to achieve anything useful. Margaret J. Wheatley Sony A7R 10-18mm f4.0, 1/2000, f/7.1, ISO200, post process CS6. |
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I like the tones in Tracks. Nice job Ferrell. Looks like you’ve gone a bit viral with the light leak video. 🙂
I think the light leak has a lot of people who have the camera concerned. It’s the type of photography that has caught camera engineers by surprise – long daylight exposures with ND filters. Sony is not the only camera so they all need to step up their machining tolerances. Keep up the great shooting John!