Tech question...struggling with light / exposure

[havoc]

Quick question for you guys. Over the Goodwood weekend I was struggling to get enough exposure on my panning shots, both on the hill and the rally-stage. Kit / settings as follows:-

EOS20D
70-300IS or 28-135IS (both used without IS...looking at the results maybe I should have switched it on, but wanted to preserve battery power), both with skylight filters only

Shutter-priority, set at 1/160 or 1/200
ISO at 200 (sun/cloud) or 400 (rain/woodland)
f/4 - f/5.6, depending on zoom level


So...was I doing something wrong? Was I expecting too much of the camera? Is there something wrong with the kit?


Thanks all,

Martin.

[RobDickinson]

"Shutter-priority, set at 1/160 or 1/200
ISO at 200 (sun/cloud) or 400 (rain/woodland)
f/4 - f/5.6, depending on zoom level"

If that wasnt letting enough light in then you needed to do something to help.

Panning etc means you cant adjust the shutter speed, that leaves opening the lens up (restricted by max apature?) or hiking the ISO another stop.

[MonkeyHanger]

Get rid of the filters and don't be scared to increase the ISO.

ISO 800 is perfectly usable on the 20D as long as the exposure is correct

[MonkeyHanger]

A quick example which should be a good reference for the Rally Stage...EXIF is intact for those with the appropriate plug-ins.

Shot in a gloomy Dalby Forest on last year's R.A.C. 1/320th@ F6.3 ISO 800 On the 20D with Sigma 120-300 (no filters )

[havoc]

Rob,

Can't open the lenses up anymore - that's at the limits. The 28-135 has an f2.8 bottom-end, but I could never get it below about 4 or 4.5 because I was zoomed-in at between 70 and 120 the whole time. The 70-300 starts at f4.

MonkeyHanger said:

Get rid of the filters and don't be scared to increase the ISO.

ISO 800 is perfectly usable on the 20D as long as the exposure is correct

Hmmm...might try that. Been loath to go above 400 as on holiday forgot to switch from ISO1600 leaving a cave and got a bunch of clearly grainy shots (until I worked out why the shutter speeds were so quick (on Aperture-priority mode).


The other problem I had was the background - depending on where I was panning I either had a neutral-darkish background, or near-white. As a result I've also got a few over-exposed shots!


Oh...forgot...I was varying the camera between 0 and 2/3 stop extra exposure, depending on the light (sun/cloud/sun/rain/hail/sun...), and trying to compensate for that damned Park Grandstand in all-white!!!

[poah]

leave the filter on lol

if your pics where dark then your shutter speed was not slow enough for the light and you shoul dhave bumped the ISO up. post an example

[havoc]

poah said:

if your pics where dark then your shutter speed was not slow enough for the light and you shoul dhave bumped the ISO up. post an example

I'd sort of worked that one out thanks. I was asking whether it sounded reasonable or not!

Looking through the pics again the main problems seem to be where there's high contrast in the shot - in the paddocks, on the rally stage, cars going under the bridge, white background when shooting across at Park grandstand.

Which, OK, I guess I should have expected. I guess I'm just surprised that what the human eye can deal with easily the camera struggles with...and I've not had any (noticeable) problems like this in the past...

[RobDickinson]

Havoc it sounds like the meetering getting confused not an outright exposure issue.

I assume you were not on full manual mode and the camera was metering, most likely on some full frame mode rather than center weighted or partial/spot.

Thats more likely to cause issues when theres realy bright and realy dark sections and the camera doesnt know/understand how you want the whole scene exposed so takes a bad guess.

Dialing in EV is only of use if the conditions are constant.

[havoc]

RobDickinson said:

I assume you were not on full manual mode and the camera was metering, most likely on some full frame mode rather than center weighted or partial/spot.

Thats more likely to cause issues when theres realy bright and realy dark sections and the camera doesnt know/understand how you want the whole scene exposed so takes a bad guess.

Dialing in EV is only of use if the conditions are constant.

That sounds like it could well be the case Rob. I was focusing on the centre-point only, but confess I've no idea how it was metering...it's an aspect of photography that still comes under the category "arcane arts" for me!

Certainly the worst results were when the cars were under/near the bridge...foreground light, background light, car and centre of pic in shadow.

[Ledaig]

havoc said:

Can't open the lenses up anymore - that's at the limits.

Oh...forgot...I was varying the camera between 0 and 2/3 stop extra exposure, depending on the light (sun/cloud/sun/rain/hail/sun...), and trying to compensate for that damned Park Grandstand in all-white!!!

If your on sutter priority and the lens is already fully open, exp comp will not make any difference as the lens cannot open further.

[TRACKDEMON]

In the abscence of a proper light meter the best technique is to take a shot of the point you'll be shooting at using multi point metering. Take a few shots until your happy with the exposure (check histogram), then dial those in as manual settings.

Effectively your trying to get closest to a balanced exposure as you'd get off a grey card then locking in the settings so the camera isn't thrown by different colour cars or more/less white in the frame..... some camera's exposure metering systems are more consistant than others! The more white there is in a frame the darker your camera's metering system will make things.

[havoc]

Steve,

Not bad advice...except not sure how much it'd have helped...I was panning and taking multiple shots, and the background went green/tan to green/white to black to multi-coloured people.

[RobDickinson]

Sounds like you were on the wront meetering mode for the job.

Meetering works like this...

It tries to turn the area of intrest to an 18% grey.

So if your meetering the whole frame it tries to adust that to 18% grey overall. If theres more bright/white it'll underexpose, more dark it'll overexpose (to whats 'real').

This sounds like what was happening - your camera meeters the whole scene, sees the bright foreground and background and says wow too bright, reduce the amount of light. Ok if your intrested in the bright areas, but you were shooting the car in the dark area in the center.

Solution? Change meetering mode. None are perfect all need help at times, its more important to understand what they do.

What you wanted is something that meeters for the car, which is rather less than full frame, not sure what modes/camera you have but your probably after either center weighted (meeters the whole scene but gives much more bias to the center 20-30%) or centerpoint (9% center on the cheap canons) or even Spot meter (3% or so center).

Something like spot meter can be much hit & miss as the whole scene too...

[havoc]

I think that's exactly what it was. Not come across it before as all the other m-sport photography so far has been at circuits with pretty neutral backgrounds. Goodwood was a little...unique!

OK, next lesson for me to teach myself...how to pick a metering mode!


Thanks for the explanations and advice Rob (and TD!).

[TRACKDEMON]

havoc said:

Steve,

Not bad advice...except not sure how much it'd have helped...I was panning and taking multiple shots, and the background went green/tan to green/white to black to multi-coloured people.

You'd still have gotten more consistant results in manual mode - take a reading from the lightest panning point, take a reading from the darkest, average the exposure then dial it in manual. Dark would be dark, light would be light, and the cars would have been consistantly exposed..... of course this ignores the vagaries of passing cloud etc altering the scene but you get the idea. Its not really practical to manual meter for every passing car @ FoS as they arrive too quickly so I think thats the best compromise.....

[jezza l]

TRACKDEMON said:

havoc said:

Steve,

Not bad advice...except not sure how much it'd have helped...I was panning and taking multiple shots, and the background went green/tan to green/white to black to multi-coloured people.

You'd still have gotten more consistant results in manual mode - take a reading from the lightest panning point, take a reading from the darkest, average the exposure then dial it in manual. Dark would be dark, light would be light, and the cars would have been consistantly exposed..... of course this ignores the vagaries of passing cloud etc altering the scene but you get the idea. Its not really practical to manual meter for every passing car @ FoS as they arrive too quickly so I think thats the best compromise.....

Interesting info in the thread, thanks guys.

I ended up doing pretty much what trackdemon said. Though because the light was changing so frequently I did struggle and some of my shots didn't come out to well sadly. I started off with IS0100 on saturday morning then as the light diminished I ended up at ISO400.