Problem with focus in darkness

[StratosB]

Hi to everyone.I use to take photos at friend's parties. I have the Nikon d3300 and I recently bought the sigma 17-50 replacing my kit one. The new lense has a bigger body so the beam from the auxiliary spot light is hidden,not at all but enough to have problems with auto focus.What I should do?
Many thanks.

 

[KmH]

Auto focus needs contrast (shadows) to work.
The built-in AF assist light should be plenty, and the Sigma 17-50 should not interfere so much with the assist light that AF can't do it's job. Unless your point of focus is way in front of the camera.
However you don't day what AF focus mode and focus area mode you are trying to use.

However, any light added to the scene aids AF, even if the light is from a handheld flashlight and/or the AF assist light.

 

[480sparky]

Buy a nice, bright flashlight.

 

[vintagesnaps]

Learn how to focus manually... Supposedly we can actually see to focus in low light better than what a camera is able to do. A camera is recording light, so low light is challenging what a camera can do.

Try to think about your vantage point - where to be and which way to face to get some light on the subject as much as possible.

 

[vintagesnaps]

Thanks Sparky, now I have a mental image of you walking around a party aiming your flashlight into the dark corners... better not do that! lol

 

[Braineack]

the lower end bodies really stink at focusing in the dark. I like when speedlights and radio triggers add beam assist -- works much better than the 1watt bulb on the body.

 

[Dave442]

If using the flash then use lens between 17-20mm and to f/5.6 and just set the focus at about 2 meters (manual focus) and start shooting. If you are using the flash then look at adding something like the SB-700 flash unit that has the infrared focus assist beam.

I have my camera set up so I can use the infrared focus assist of the flash unit, but then have a function button set so when I push it the flash does not fire (so I can focus in the dark and only use the flash when I want to).

 

[480sparky]

Thanks Sparky, now I have a mental image of you walking around a party aiming your flashlight into the dark corners... better not do that! lol

Is that when I wear my scuzzy raincoat?

 

[vintagesnaps]

Oh, I hope not. If you do, keep it closed...

 

[KmH]

the lower end bodies really stink at focusing in the dark. I like when speedlights and radio triggers add beam assist -- works much better than the 1watt bulb on the body.

Yep the entry-level DSLRs have AF modules that are less capable than the AF modules in the enthusiast, prosumer, and pro grade DSLR cameras.

The D3300 has the basic Nikon Multi-CAM 1000 AF module that has 11 AF points, only 1 of them (the one in the middle) a cross-type AF point.
By comparison the D7200 has Nikon's Multi-CAM 3500 II AF module that has 51 AF points 15 of them (an array in the middle) being cross type AF points.
Cross type AF points work better than non-cross type AF points.
Understanding Camera Autofocus

 

[adamhiram]

The D3300 has the basic Nikon Multi-CAM 1000 AF module that has 11 AF points, only 1 of them (the one in the middle) a cross-type AF point.

I think this is probably your best bet - stick with the center focus point in low-light situations, and learn to focus and ended. I think you’ll see a lot more keepers. I had this same issue with my D5100, and this was the solution that worked for me.