G10, Manual underexposed

[Tom Kreider]

Need some help here, please.

I'm trying to learn how to use manual mode, using pointers in this forum and with some pricey underwater photography books. However, my trial shots (above water) always are way underexposed. For example, I set the G10 on full Auto, take a very well exposed shot, and then look at the settings the G10 choose, ISO, Shutter speed, Aperture, etc. I then go to Manual and adjust to the identical settings, and the histogram (& LCD screen) show that the show will be way to underexposed, click, and it is... what gives? Any help is appreciated. I leave for the Aquacat in 12 days and I'd hate to have to resort to "full auto" or "underwater scene" for the whole week.

I should say that this is using no flash. With flash, everything is fine, but without, I seem to need to open the aperture full to 2.8 and then set the shutter speed to way to long to get proper exposure in manual. Yet, in Auto, it shoots just fine without flash and with reasonable settings.

Please help. Thanks!

 

[PlanetMarz]

Tom,

Have you looked to make sure you didn't move the exposure compensation dial on top of the camera on the left side? If you accidentally spun the dial to -1 it would be underexposed without flash but ok with flash.
Not much else I can think of except that you should be shooting in Raw which means that you need to get comfortable with M, Tv, Av or P. Program mode may be your best bet if you are used to shooting full auto.

I just got my G-10 a while ago and I love it - the image quality doesn't keep up with my DSLR but its small and relatively light and takes really nice images for a Point and Shoot.

Good luck,
Curtis

EDIT - after re-reading your post I would also recommend that you review how your camera is metering the scene as well as disable the auto ISO adjustment. Try to shoot in M or Av - Program mode is also a nice way to go if you are shy about using M. I have had to go deep into the menus to find all the different metering and "auto" settings.

 

[Tom Kreider]

Curtis, thanks for your thoughts. Yes, shooting RAW and no, the exposure adjustment is set at 0. I've tried all three metering modes, spot, evaluative, and center weighted. Manual still looks dark. I'm not actually shy about manual, I'm just trying to figure out why, with the same settings as Auto, everything is underexposed in Manual. Thanks again.

Still looking for ideas.

 

[M_Bipartitus]

I would start with partial manual settings such as Av or Tv. Most Canons don't change many settings when you change between Av, Tv, and M, so you may have better luck comparing the exposures from Av and manual. You will need Auto ISO off.

When I shoot underwater (or above for that matter) I mostly use Av. This allows me to control aperture (thus depth of field) and the camera takes care of shutter speed. When using strobes, I set exposure compensation to -1 or even -2 and eTTL takes care of the proper flash exposure. This allows me to keep the background dark (-2 stops) and have the close subject properly exposed. This works for may subjects, but is a creative choice. That is it tends to separate the subject from the background. For example, this shot was done so that the strobes lit the front of a coral head and the coral farther back had less exposure.

The only time I use Full Manual mode is if I already know a good exposure value (from Av, for example), if I want almost only strobe light (say a night dive), or if I'm using the 40 year old film camera.*


It might help if you posted a sample list of settings and the photos in both Auto and Manual modes.


* Honestly, when I use the old Hasselblad I still typically take a few frames with the dSLR to test the exposures. I know of some large format photographers who use G9/G10 for this. They used Polaroid back in the day.

 

[Jeff Toorish]

Here are a few thoughts that might help.

Digital sensors are not like color negative film, they are like color chrome film. That is a significant difference. With a digital camera, it is critically important that you expose for the highlights, not the shadows. The shadows are going to be dark, that's the nature of the animal --but you can do a lot to bring out the shadow detail in post processing. If you expose for the shadows, you are going to blow out the highlights and you will never get anything out of an over exposed highlight.

Every camera has its own oddities --I use a g9 for some shoots and I find it's exposure is pretty much what I would expect from my SLRs but maybe the g10 is different.

I advocate using an incident light meter, even though pretty much all cameras today have very sensitive built in meters. The incident meter is still an excellent starting place for exposre.

If I don't have my incident meter with me, I can still get a pretty good exposure starting place using the sunny 16 rule.

Hope this helps.

Jeff

 

[Tom Kreider]

Thanks to all for your input. I'm gonna have fun exploring this camera!

Sunny 16 Rule...

 

[Packhorse]

If all settings are the same then the exposure should be the same unless the lighting has changed. Something is different But what?? Perhaps its the ND or neutral Density filter turned on in manual mode but not auto???

 

[Tom Kreider]

Exactly!!! I've spent a few hours with the user guide and the menus on the G10. I've recreated every setting that I could find was used in the Auto shot and set that exact setting in Manual... the manual shot comes out darker.

the search continues...

 

[jimorus]

Why not try actually metering in manual. A grey card is nice but there are plenty of things that are close enough. Green grass in the same light as your subject is one. The northern sky, away from the sun, is another. I have even used old asphalt at an airshow.

After you understand the meter you can even use the back of you hand. It is always with you. Just meter off a known value, say green grass that is in the same light as your hand. Then meter off your hand. Depending on your skin color or tone you may be a bit over exposed or under exposed as compared to the grass. In my case correct metering off my hand would be to adjust shutter and aperture to show approximatly one and a half stops over exposed.

Then there is always the sunny f16 rule--Full sun use f16 and 1 over the film speed. Since the camera only goes to f8, use 1 over twice the film speed.
Example set iso to 100--the film speed
The proper exposure in full sun is an aperture of f16 and a shutter speed 1/100--1/125 is close enough
Since you don't have f16 use f8 (one half of f16) and a shutter of 1/200(twice as fast as 1/100)

When my wife and I were self teaching 35mm slr we shot hundreds of rolls of film before we understood that meters can be fooled by reflective or unusually bright objects.

Sail boarding is full of color and full of action but the reflective water just blows the meter away. Using the meter and whatever auto mode just underexposed everything. If we turned away from the water and zoomed in on a tree in the sunlight and manually metered on the leaves and then turned around and shot the sail board shots manually they were dead on.

a bit of experience developing showed us that digital is a bir more sensitive to exposure and as far as sucking a bit more out of a negative is different than from a digital file. Film gives you a range of exposure than can get you a good shot from 2 or 3 stops underexposed to 2 or three stops overexposed. Slide film maybe a stop or a stop and a half either way. On both it is easier to pull a picture from a bad neg with more or less light when printing.

Digital is closer to slide film than negative film when you shoot and print, but when you do digital manipulation you can get the same six stops as negative film by stacking layers and using different blending modes and layer masks.

Annd for those that may feel Photoshop is cheating you can bet that most everythign you see from negs has been custom printed and dodged and burned. With Photoshop you dodge and burn yourself with no toxic developing chemicals, dark room machinery ore secret recipes.

jimorus

 

[Tom Kreider]

Wow, more stuff to learn. Thanks!!!