topic T3i Failure to Focus on Low Light in EOS DSLR & Mirrorless Cameras

T3i Failure to Focus on Low Light

tconstan — Fri, 12 May 2017 18:15:27 GMT

My T3i with the kit lens (18-55 f3.5) hunts relentlessly when shooting in low light. Tried higher ISO but still cannot grab a proper focus. Additionally, when a flash is added (Sunpak 3000) it still has trouble finding focus. All ideas are welcome.

Re: T3i Failure to Focus on Low Light

kvbarkley — Fri, 12 May 2017 18:35:45 GMT

Are you using the disco flash?

Does the Sunpak have IR assist?

Re: T3i Failure to Focus on Low Light

ebiggs1 — Fri, 12 May 2017 22:05:00 GMT

Does the Sunpak 3000 talk to the Rebel? If it doesn't, it doesn't help that it is there. You might try a 430EX instead.

Re: T3i Failure to Focus on Low Light

ScottyP — Fri, 12 May 2017 23:18:30 GMT

I had a T3i that would hunt and hunt indoors. Not even in all that dark a scene. It was one of the main reasons I upgraded. It is frustrating and even sort of embarassing to be trying to take a picture but instead, while your subject stands there, your camera is putting on a protracted buzzy strobe light show with the AF assist light trying to focus.

The T3i can only AF in dim light down to -0.5EV. Same with T4i, T5i and T6i. The T7i now autofocuses down to -3EV, which is the same as the 6d, and now the 5D4.

Re: T3i Failure to Focus on Low Light

tconstan — Sat, 13 May 2017 12:31:32 GMT

Ebiggs1, thanks for comment. The 3000c is supposedly an ettl unit.

Re: T3i Failure to Focus on Low Light

tconstan — Sat, 13 May 2017 12:34:03 GMT

Scottyp, thanks for comment. I am frustrated and close to upgrading. Tryng to decide t6i or t5i. The t7i is a bit pricey right now.

Re: T3i Failure to Focus on Low Light

Waddizzle — Sat, 13 May 2017 13:15:57 GMT

@tconstan wrote:
Scottyp, thanks for comment. I am frustrated and close to upgrading. Tryng to decide t6i or t5i. The t7i is a bit pricey right now.

As long as your T3i is still in good working, then either a T5i or a T6i would be more of a replacement than a significant performance upgrade. A T6s would come closer to being an actual upgrade than either of those bodies.

The T7i seems to be aimed to occupy the top spot in the Rebel lineup. It looks to be a good camera, but I have reservations about battery life between charges, because of its' smallish battery.

The 80D is a best buy in the Canon DSLR lineup, IMHO. Look for it in the Canon Direct eStore Refurbished section. There should be a link to the Online Store in the lower right corner of the forum pages.

The best way to improve your photos is to use better lenses. But, quality lenses tend to cost even more than camera bodies, although there are a couple of good Canon lenses selling at thrifty prices. The "nifty fifty" EF 50mm f/1.8 STM lens is a great lens, and an EXCELLENT teaching tool because of its' wide f/1.8 aperture. If you do not own a "fast lens", meaning f/2.8 aperture or better, then I recommend that you consider giving a lens upgrade a thought.

Re: T3i Failure to Focus on Low Light

tconstan — Sat, 13 May 2017 13:22:38 GMT

Waddizzle, thanks for your opinion. I have been looking at refurbished and will probably go that way. All but one of my lenses is Canon: 50mm f1.8 from my old Elan, 10-18 f3.5, 18-55 and 55-250 kit lenses and a Sigma 28-200mm f3.5. All are terrible in low light with the 50mm beeng passable.

Re: T3i Failure to Focus on Low Light

Waddizzle — Sat, 13 May 2017 14:37:31 GMT

@tconstan wrote:
Waddizzle, thanks for your opinion. I have been looking at refurbished and will probably go that way. All but one of my lenses is Canon: 50mm f1.8 from my old Elan, 10-18 f3.5, 18-55 and 55-250 kit lenses and a Sigma 28-200mm f3.5. All are terrible in low light with the 50mm beeng passable.

You're not going to get very good low light performance from a Rebel. I do not know, yet, how well the T7i can perform in low light. The 80D is very good in low light, and produces images with much less noise than the 7D Mark II.

The 6D has long been one of the best cameras for low light. The 80D is nearly as good the 6D. The above photo was shot with a 6D and the EF 70-200mm f/2.8L IS II USM lens, with standard room lighting. The settings were 1/125, f/2.8, ISO 10,000.

The bar had about 15 foot ceilings and used the older, incandescent "hi-hats" light fixtures mounted in the ceiling tiles. It was a two story building, with the upper floor removed to create a larger open space.

The 77D could have low light performace similar to the 80D, I wouldn't know. The 77D looks to be a great camera, except it has the same small battery as the T7i. I don't think there will be Canon battery grips available for either one of them, either, which I find to be rather curious. Maybe, they just don't sell many grips in that customer demographic.

Having a grip can make a big difference with a large lens, with it's large focusing motors. The 1D series have a battery grip already built into the camera body. I recently spent several hours wandering around the woods and a couple of lakes, with the Canon EF 100-400mm Mark II.

I shot over 700 photos with a 1D Mark IV, and battery indicator still had full bars. I use BBF. Disabled the auto-preview after every shot. And, I also disable the camera body to keep hunting for focus if it gets lost.

Re: T3i Failure to Focus on Low Light

tconstan — Sat, 13 May 2017 19:38:43 GMT

Kvbarkley, the 3000c has infrared assist. I don't understand disco flash reference.

Re: T3i Failure to Focus on Low Light

Waddizzle — Sat, 13 May 2017 20:09:50 GMT

@tconstan wrote:
Kvbarkley, the 3000c has infrared assist. I don't understand disco flash reference.

Cameras with the built-in flash can use it as a "focus assist" beam.

It is a feature that can be enabled or disabled, depending your mode dial setting on top of the camera. During a low light focus scenario, the camera will raise the flash, and then rapidly fire it like a strobe light in a disco.

Whether or not the flash will fire when you take the shot is an entirely different setting. Again, by "disco flash", he means "focus assist."