D200 AF assist lamp.

[neil_parker]

I am wondering if the D200 AF assist lamp is useful with all lenses, or just the low end

zooms. With my 17-55 f2.8, the lamp is completely blocked with the hood, but seems to

work a bit with the hood removed.

 

I prefer using the (enormous) hood when possible, so am wondering whether the light

adds any help to this AF-S lens. Nikon recommends removing the hood when using. But I

found that this lens does a good job of focussing w/out the lamp, even in marginal light.

[frank_skomial]

"with all lenses, or just the low end zooms."

 

Read in your manual for D200 range of operation of the auto focus assist light. You may discover that the range is very short, so perhaps more appropriate for wide to normal lenses ?

 

What gave you idea that is is just for low end zooms ? because they are not huge ?

 

When assist light is blocked by a huge lens hood, the light assisting performance is degraded, but usually operates with whatever assist light exists.

 

You can see that lens hood can cast a shade on part of the photographed area when assist light is ON, so one would assume that a wider lens see more area, and can see also areas that are not in the shade caused by lens hood.

 

Selection of matrix metering could help.

[neil_parker]

Little info on the assist lamp in the manual. Just an EV range that the AF will work in. How

does matrix metering (which I am using so far) affect the AF? Sorry if these question are

basic, I am new to AF, as well as to the D200 :).

[frank_skomial]

Hi Neil,

 

No need to be sorry, and everybody needs to ask questions, mainly because Nikon's publications lack desired depth of information.

 

The Matrix metering covers more or less entire frame, so the areas that are not shaded by the lens hood are also visible, and the lens hood obstructing impact on measurements is lesser.

 

Possibly, when spot metering, smaller area is taken into consideration, and at close distance, that could happen to be the shaded areas, (shade caused by the hood for the focus assist light).

 

So, in Matrix metering huge lens hood impact is less affecting the auto focus.

 

I used a rubber hood for my 20 mm lens that was way too big, and replaced it with a smaller and shorter metal hood (having the same angle of view as the rubber type), and auto focus works much better, in low light condition, and even with spot metering.

[richard_speer]

So, should I ONLY use the lens hood in bright light situations?

[ramon_v__california_]

the lens hood is used primarily to block off unwanted light.

so there is actually no need for the AF-assist lamp. you normally turn that off. well, i do.

 

i also have the 17-55mm on my D70 and use the hood. and yes, there is logic in using matrix metering against spot when using the 17-55mm with the hood on situations when you want or need to use the AF-assist lamp.

 

have fun with your excellent combo.

[todd1664878707]

I always keep my lens hood on even in dark venues when I don't have to worry about stray light. The hood doubles as a lens protector. I usually carry at least two cameras on me and one is usually swinging around. The first thing that makes contact with something is usually the front of the lens. This way, the hood will protect it. Also, it's a lot harder to have something rub up against the front of the lens and scratch the glass if there is a hood on.

[richard sweet]

I have the same problem with my D200 and Sigma 24mm-70mm f2.8. It also blocks the in-built flash at the wide end of the zoom, creating a ugly dark round shadow on the rottom edge of the frame.<p>

A easy way round it is to get a SB-600 or SB-800, this should get rid of the flash problem and also help the AF assist as they both have a wide "AF Assist Illuminator".<div></div>

[lex_jenkins]

Choosing one of the single sensor focus bracket options can often greatly improve AF performance in difficult lighting. The fancier multi-sensor options are best reserved for use in brighter light.

 

In low light the SB-800 projects a red cross-hatch pattern as a focus aid. And there's plenty of clearance for any lens hood. It can be set to project the AF assist pattern without activating the flash, but it's not a perfect solution. For one thing, it's big and heavy for use just as an AF assist lamp. For another, it doesn't offer an always-on option - the flash/camera decide when the lamp is needed. But it helps.

 

Presumably the SB-600 offers the same feature. Dunno whether the new SU800 offers this feature. If so, it would be smaller and lighter in weight and still provide clearance for large lens hoods.

[neil_parker]

Thanks for the tips, I have been using this with only the single central AF bracket, on 'S'

focus mode. (except w/ my AIS/AI lenses of course). The first day I used in to shoot a band

in a nice night club, dividing my pics between available light 1600 and flash 200.

Unfortunately I will be limited to my antique viv 285 for some time, it will be a while before

an SB 800 is in the budget:(

 

If I understand correctly; using matrix metering with the hood and AF assist will benefit my

exposure accuracy, not my focus accuracy, right? Really it seems to me that the AF assist

light adds no benefit when the 17-55 hood is used.

 

I found the focus w/out the assist to be quite crisp and fast in the ever-changing light

situation of a live musical perfomance. And uh that zoom is sharp.<div></div>