snubbr.com

AF assist light - how much does it help?
I'm planning to buy an amateur/enthusiast DSLR within the next six months. There are a few candidates, one of them has everything I'm looking for (or at least it looks like - it will probably be announced at PMA), except an AF assist light..

Now I'm wondering how much such a lamp really helps?.

Does the AF not work without it in low light situations at all, less accurate or just slower?How many low light photos do I "loose" without it?.

I plan to get a 1.4 or 1.7 prime lens for low light situations, in case the lens has a role in this, too...

Comments (12)

Ulrichsson wrote:.

Now I'm wondering how much such a lamp really helps?Does the AF not work without it in low light situations at all, lessaccurate or just slower?.

Basically the name says it all. It's a lamp designed to send out something the AF system can see with. It does help the AF system with objects close enough to be illuminated by the lamp. It does help in low light situations, but ONLY with getting an AF lock..

How many low light photos do I "loose" without it?.

An impossible question to answer. It would depend on every single specific of what you do and each shot's detailed circumstances..

I'm under the impression all DSLRs have some AF assist, usually by raising the camera's flash ( this does not mean flash has to fire ! )..

I plan to get a 1.4 or 1.7 prime lens for low light situations, incase the lens has a role in this, too..

You don't know what the lens will do for you but you are buying it anyway ? .

Please don't..

A prime lens ( and they come in all sorts of shapes, sizes and focal lengths ) will not get you a perfect low light shot. Use a flash if you can or use a long exposure and/or high ISO if you cannot. Using a prime with a wide aperture is difficult on a DSLR because two things happen at wide apertures. First depth of field is small ( it can be extremely small ), which means that only a very narrow range is in focus. This makes, e.g. close up shots of in-focus faces difficult.



You can, indeed, use a wide aperture lens to get low light shots, but it's harder than it sounds - a lot harder. The easy way is using flash where possible..

Camera have flashes for a reason. And on a DSLR you can raise ISO quite high and get acceptable result. It's best to get used to using kit lenses before spending money on lenses you don't know the pros and cons of..

StephenG.

Pentax K100DFuji S5200Fuji E900PCLinuxOS..

Comment #1

Ulrichsson wrote:.

I'm planning to buy an amateur/enthusiast DSLR within the next sixmonths. There are a few candidates, one of them has everything I'mlooking for (or at least it looks like - it will probably beannounced at PMA), except an AF assist light..

Now I'm wondering how much such a lamp really helps?.

A great deal..

Does the AF not work without it in low light situations at all, lessaccurate or just slower?.

MUCH less accurate and it will hunt..

How many low light photos do I "loose" without it?.

Depends on your lens and camera..

I plan to get a 1.4 or 1.7 prime lens for low light situations, incase the lens has a role in this, too..

The lens and any filters have a HUGE roll..

The AF assist helps a great deal. However if you have a really fast lens in many cases it is not needed. The AF assist on my Oly 510 is a pain (and I can only speak for the E500, E410, and E510). First it is very bright (I know, that's what you use it for). Second there are many times you DONT want to use a flash but you DO want to autofucus. With the my camera you would loose MANY shots in low light without the AF assist AND while using a slow lens.

A 1.4 or 1.7 should do very weill in general. Just remember if the camera can't see it, it can't focus any better then you could if you can't see it (and your eyes are generally better then any DSLR will be).Olympus E-510 and a bunch of stuff to hang on it...

Comment #2

Thanks for the answers. I think I have a better idea of the issue now..

I only have one more question: How does an AF assistent that raises the flash (without firing) work?..

Comment #3

Ulrichsson wrote:.

I'm planning to buy an amateur/enthusiast DSLR within the next sixmonths. There are a few candidates, one of them has everything I'mlooking for (or at least it looks like - it will probably beannounced at PMA), except an AF assist light..

Now I'm wondering how much such a lamp really helps?.

It's worth the extra money, as it does help significantly in finding and locking focus. If the camera doesn't have an AF assist lamp, you can always purchase a flash that will have it (at least for most major and minor brands discussed here on DPReview)..

Does the AF not work without it in low light situations at all, lessaccurate or just slower?.

It may or may not work depending on how dark the situation is. If it is completely black, you'll require an AF assist lamp, period. If it is very dim, the AF may hunt and hunt and hunt and never find focus. Using an AF assist lamp will help it achieve focus much faster. In poor lighting (but still adequate for AF) the lense may hunt and finally, after a second or two, find and lock focus. It may or may not be accurate, but with an AF assist lamp it would likely be spot on..

How many low light photos do I "loose" without it?.

Of course this question is unanswerable, as you've found out..

I plan to get a 1.4 or 1.7 prime lens for low light situations, incase the lens has a role in this, too..

A fast lense allows more light to hit the sensor and AF unit - more light allows more accurate AF. A faster lense will therefore allow faster and more accurate AF in low light situations than a slower lense would. In some cases very slow lenses cannot focus in low light at all. An example would be an f/5.6 lense with a 2X teleconverter on it - the effective aperture is f/11, and I don't know of any cameras that support f/11 AF in low light. There's just not enough light to divert to the AF unit..

Tim'Be the change you wish to see in the world.' -Mahatma Gandhihttp://www.flickr.com/photos/timskis6/..

Comment #4

Ulrichsson wrote:.

Thanks for the answers. I think I have a better idea of the issue now..

I only have one more question: How does an AF assistent that raisesthe flash (without firing) work?.

? Not sure what you're talking about. Some cameras may have the AF unit built into the pop up flash, but I can't recall any (if at all) have this. Some cameras use a strobing flash to find AF rather than an AF assist lamp. I really, really hate these, as do many other people..

Tim'Be the change you wish to see in the world.' -Mahatma Gandhihttp://www.flickr.com/photos/timskis6/..

Comment #5

Ulrichsson wrote:.

I only have one more question: How does an AF assistent that raisesthe flash (without firing) work?.

It doesn't. What's happening is that by the time the flash is up the camera has actually found a focus so doesn't need to fire the flash...

Comment #6

Just to be clear the Oly uses the strobing flash. And you are correct. I hate it. It is one of the few things that I would change about the camera..

MaddogOlympus E-510 and a bunch of stuff to hang on it...

Comment #7

Below you may find your answer:http://www.dcresource.com/forums/showthread.php?t=35675and here:http://en.wikipedia.org/wiki/Autofocus_assist_beam.

Ulrichsson wrote:.

I only have one more question: How does an AF assistent that raisesthe flash (without firing) work?.

Best Wishes, Ajayhttp://picasaweb.google.com/ajay0612..

Comment #8

Acsmith wrote:.

Ulrichsson wrote:.

I only have one more question: How does an AF assistent that raisesthe flash (without firing) work?.

It doesn't. What's happening is that by the time the flash is up thecamera has actually found a focus so doesn't need to fire the flash..

That's not right: the flash emits several short low-intensity flashes, which work in a way similar to what a focus-assist lamp would do in a camera equipped with one, enabling AF to work in low light (even in no light at all) situations..

It's just a different arrangement to achieve the same goal..

A focus assist lamp usually emits a strong red beam (which can be quite annoying to the subject -e.g.a small child), whereas the short low-intensity flashes from the onboard flash are white and similar to the low intensity pre-flashes, preceeding the "main" flash, used to eliminate red-eye in many cameras..

You "pays your money and takes your choice!" ..

Comment #9

Maddogmd11 wrote:.

Just to be clear the Oly uses the strobing flash. And you arecorrect. I hate it. It is one of the few things that I would changeabout the camera..

Yes, most Oly's use it, some don't. Even the E-3 uses it if the flash is popped up, but I find that (with the 12-60mm) AF is much faster if you don't use the strobing flash and only use the camera's AF mechanism. Oly decided not to put an AF assist on the E-3, claiming AF was good in low light and didn't need it. They are correct, it is good in low light, but still not as good as other cameras - it surely could have benefited from an AF assist lamp. I think it was the marketing that kept it off the camera..

MaddogOlympus E-510 and a bunch of stuff to hang on it..

Tim'Be the change you wish to see in the world.' -Mahatma Gandhihttp://www.flickr.com/photos/timskis6/..

Comment #10

AF assist has a maximumj range of about 10 feet. Given that 95% of my photography is low light and well beyond that range (theatre photography) the AF assist on my D80 and D50 are switched off by default..

I have few problems with AF even without it. Maybe I would have if regularly using an f/5.6 lens..

Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

Comment #11

I have specifaically experienced the flash popping and not firing at all - not even a tiny amount...

Comment #12

Click Here to View All...

Sponsored Amazon Deals:

1. Get big savings on Amazon warehouse deals.
2. Save up to 70% on Amazon Products.


This question was taken from a support group/message board and re-posted here so others can learn from it.

 

Categories: Home | Diet & Weight Management | Vitamins & Supplements | Herbs & Cleansing |

Sexual Health | Medifast Support | Nutrisystem Support | Medifast Questions |

Web Hosting | Web Hosts | Website Hosting | Hosting |

Web Hosting | GoDaddy | Digital Cameras | Best WebHosts |

Web Hosting FAQ | Web Hosts FAQ | Hosting FAQ | Hosting Group |

Hosting Questions | Camera Tips | Best Cameras To Buy | Best Cameras This Year |

Camera Q-A | Digital Cameras Q-A | Camera Forum | Nov 2010 - Cameras |

Oct 2010 - Cameras | Oct 2010 - DSLRs | Oct 2010 - Camera Tips | Sep 2010 - Cameras |

Sep 2010 - DSLRS | Sep 2010 - Camera Tips | Aug 2010 - Cameras | Aug 2010 - DSLR Tips |

Aug 2010 - Camera Tips | July 2010 - Cameras | July 2010 - Nikon Cameras | July 2010 - Canon Cameras |

July 2010 - Pentax Cameras | Medifast Recipes | Medifast Recipes Tips | Medifast Recipes Strategies |

Medifast Recipes Experiences | Medifast Recipes Group | Medifast Recipes Forum | Medifast Support Strategies |

Medifast Support Experiences |

 

(C) Copyright 2010 All rights reserved.