AF Assist for Canons 61/41 AF

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I covered a major event in Trinidad this weekend - its called a carnival band launch, is a promotion for Mardi Gras 2013 held by all the major carnival promoters in Trinidad. It was an outdoor night amphitheater type environment where the conditions except for the main presentation are all low lighting conditions. I posted on
some of the challenges and summarized the shooting for what was my first major night event with the 5DM3 on my blog. I am amazed that you can get shots like this http://www.wilmark.johnatty.com/harts2013/h30876b03#h30876b03 at ISO25600, and there are many more at ISO25600. The biggest challenge is getting focus fast enough. Its a real pain. I wish somebody designed something to make the Canon 61/41 system perform better in dim light situations. Like a shoe mounted LED lamp. I know i can put a full flash and just maybe use the preflash, but this makes the set up heavier. And that issue with the black squares really messes things up too. You can only get focus when there is enough character in your framing with light in it. This really hampers your ability to use the low light capabilities of the new cams. What do you do to solve this issue? Are there any commercial products?



My blog here:
http://www.wilmark.johnatty.com/blog/2012/8/harts2013NightPhotography
The galleries shot are here:
http://www.wilmark.johnatty.com/harts2013/h356af3bf#h356af3bf
you can see the carnival presentation from here:
http://www.wilmark.johnatty.com/harts2013/h88fce06#h88fce06
 
R

Richard Lane

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Wilmark said:
I covered a major event in Trinidad this weekend - its called a carnival band launch, is a promotion for Mardi Gras 2013 held by all the major carnival promoters in Trinidad. It was an outdoor night amphitheater type environment where the conditions except for the main presentation are all low lighting conditions. I posted on some of the challenges and summarized the shooting for what was my first major night event with the 5DM3 on my blog.

..I wish somebody designed something to make the Canon 61/41 system perform better in dim light situations. Like a shoe mounted LED lamp. I know i can put a full flash and just maybe use the preflash, but this makes the set up heavier. And that issue with the black squares really messes things up too.

That looks like a really fun event. I'm jealous! My Father used to have a 52 ft. Sailboat (sold it 2 years ago) and we used to take it down to Antigua every year for Antigua Race Week and they used to have events like this too, and those were some of the best times I've ever had!

Anyway.., were you using AI Servo or One Shot, because AI Servo can struggle in low light and One Shot performs much better, except you will have to re-acquire focus after each burst. Also as stated in the other thread and in the Canon Manual, Spot AF is not recommended for low light situations, and AI Servo doesn't work well for stationary subjects in low light (when the subject distance to the camera is not changing).

I thought I read that the Flash AF assist beam doesn't work with AI Servo, in case you were using Servo?

Rich
 
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Hi Richard, thanks for the comment, Trinidad is the party capital of the Caribbean and there are big events like this every week. Its alot of fun putting your pics on facebook and seeing all the tags and comments, while you keep the HQ images linked on your server (Zenfolio in my case).

Thanks for the info about the best settings, I have never considered this for these situations. Although for the night in question, i was using single shot i believe, as there was not very much action. I played with the Playing with the point settings as much to get focus though, I used Expand Area AF and Zone AF.
 
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Richard Lane

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So, by Single shot, I'll assume that you mean One Shot and not single shooting.

There has also been some talk that shooting over 10fps can diminish AF capabilities in low light and Canon also addresses these limitations in the Manual, so you may want to limit your high speed continuous shooting to 10fps or less, especially in low light, low contrast situations in AI Servo. One Shot AF Mode performs better under these circumstances.

As far as AF point selection, if you have some slow moving subjects then I would use single point with 4 point expansion, so that you have better AF accuracy. Zone Expanded Area AF picks the points for you, so it may not pick the point that you want, especially in low light, low contrast situations. I'm defintely recommending that you place the AF point where you want it on your target, so that you may select a higher contrast area or an edge of the person or their clothing. If you leave it up to the Zone Area AF, that wont happen, since Zone Area AF likes to look for the closest part of your subject to focus on. Face detection is also poor in low light, low contrast situations, or with faces that are smaller and/or farther away.

Single point AF (4 point) area expansion may assist in low light low contrast, not because it lets more light in, but because the AF expansion area has the potential to expand to cover a larger area, so it will have a greater chance of locking AF on an area of higher contrast due to it's greater coverage area. The opposite is true of Spot AF, it will struggle due to the lower surface area that it covers on your subject.

I hope this helps!

Rich
 
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Sorry - it should be didnt move - I just used Zone AF and Expansion. I didnt try point +4. But I will now. I see the Trigger with the laser assist from wansen will ship from china in early sept, so i will wait for it to show on amazon. I think we will see a few autoassist products coming available in the next few months.
 
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I have been happy with my ST-E2, in a pitch black room I can nail focus with my 30D on a smooth (no texture) white wall at about 25-30 ft. Impressive, considering I normally can't lock focus on a smooth, white wall in good light because there isn't even enough contrast to detect a phase difference. Works perfectly with my 420EX flashes, and I've discovered in a small enough space line-of-sight is not needed to remotely trigger the slave flashes (do to reflections around the room). Very happy with my purchase (although I didn't pay nearly what the MSRP is, because I bought it broken and repaired it).

Downside on the ST-E2 is that it takes the [now rare] 2CR5 battery. Check to make sure it is available in your area (locally, or supplied by retailers that ship to Trinidad) before buying.
 
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