Aperture and shutter speed

[Anonymous]

Ok, guys- I need some hand holding here.

Was fiddling around with my Coolpix 4300 last night trying to employ some techniques you folks have been edumacating me with. Namely, increasing the aperture, and shutter speed. I don't quite understand everything yet, so forgive my ignorance.

So I figured out how to work the aperture, but it seems this camera only has two settings- minimum and maximum (2.8 or 7.6, I think). I used the maximum for snapping fish pics. Ok, shutter speed- I started with 1/100. That was way too dark. 1/60- still too dark. (no flash, BTW) 1/30- better, but still dark. Less than that, I got blurry fish.

I don't have a remote flash. I tried it with the flash on, but no success- not sure if the metering is set funny, or if it overrides my manual settings when I put the flash on.

Do I have the right concept for snapping fish pics- increase the aperture and decrease the shutter time? How do I get it from being so darn dark?

Any suggestions? Not even sure if this camera can use a remote flash even if I did have one.

Thanks,
HD

 

[Len]

By increasing the aperature, it means using the smaller f-stop number. It's kinda confusing, but f/2.8 is a bigger aperature then f/8. So go with 2.8 or as big as the camera will allow. THe bigger the aperature, the more light it lets in through the lens and the faster you can set the shutter speed.

As you found out, the faster the shutter speed, the darker the picture is because it doesn't let enough light in. But at the same time, the clearer the picture is because it captures the image faster. Go as fast as you can. A little underexposure is ok and can be corrected in photoshop. In fact, underexposure for digial cameras is recommended because sensors have a relatively narrow dynamic range and it's best not to overexpose because you can't retrieve lost highlight information. However, post processing is quite capable of retrieiving dark shadow information, hence slightly underexposing for digital is preferred.

There's also one other setting you can adjust to try to get faster shutter speeds: Exposure compensation, aka EV. Try setting the EV +1 to +3 to see what works best for your situation. This type of compensation will allow you to be 1 to 3 "stops" faster, which means you can use significantly faster shutter speeds to capture sharper images.

Whew ..... that was a mouthful. HTH. I know it can be a little confusing.

 

[Anonymous]

Yes, that does help, Len. Thanks.

Hm. I could swear I tried the 2.8 setting with the same shutter speed, and it came out darker than the 7.6 aperture. But then, I didn't even know what that really meant, so there's a strong chance I am wrong about that.

Ah, the EV thing may indeed be helpful! It sounds like that could take care of my problem.

Underexposed is an understatement for these pics. As soon as I get photoshop up and running again, I'll experiment.

Thanks!

HD

 

[Len]

F stop is the ratio of the "openness" of the blade to the focal length. The closer you get to 1, the more open it is (1:1 ratio is wide open). A F2.8 aperature will allow twice as much light in as a F5.6 aperature, and a F5.6 will allow twice as much light as a F11 aperature (ad naseum). So the smaller the F-stop number, the more open the aperature is and the more light gets to the sensor during any given period. The more light getting to the sensor, the faster you can set the shutter speed to capture moving objects.

FYI: photoshop can retrieve shadow details really well, but clipped hightlights can't be retrieved. Install photoshop and work with some underexposed images and you may be pleasantly surprised Try to get exposure as right on as possible though, since retrieving details from underexposed images tends to make the photo noisy/grainy.

On a similiar topic, depth of field is directly related to how you set your aperature, but because the sensors on consumer cameras are so small, all the images have pretty deep depth of fields regardless of aperature (relatively speaking compared to 35mm or even dSLR size sensors). That's why it's harder to get the blurry backgrounds with consumer cameras.

 

[Anonymous]

So is it just me, or does a 2.8 setting seem like a strange maximum? Is it usual for a consumer camera to only have two choices, or am I doing something wrong?

 

[Len]

The maximum f-stop is lens dependent, and f2.8 is actually a fairly common max. I'm not familiar with the 4300, but it is not uncommon either for consumer cameras to have limited fixed aperature settings. For prosumer and pro cameras, you can usually adjust aperature by 1/3 stop increments, but consumer cameras sometimes limit you to two or three aperatures.

 

[Anonymous]

Well as Jack Johnson would say, I guess I have the f-stop blues.

Photography and reefing shouldn't go so well together. They're both too expensive to do at the same time! :lol: I want a dSLR...........

 

[mkirda]

Do I have the right concept for snapping fish pics- increase the aperture and decrease the shutter time? How do I get it from being so darn dark?

Any suggestions?

It sounds to me like the settings used are wrong.

Here is what you can do to learn how things work wrt shutter speeds, aperture and depth of field...

Set the camera on a tripod. Focus on something in a constant, even light field. At night, in a room, with the lights on is perfect for this. The object you focus on can be as simple as a cup on a table...

Set lens setting for the largest f-stop available. Next, start shooting at each shutter speed you have available. You can do it by stop if you want, cutting the shutter time in half each time from one second. (i.e 1 second, 1/2 second, 1/4, 1/8th, 1/16th, 1/32nd, 1/64th, 1/125th, 1/125th...)

From there, you will find a couple which are *close*, but one should be light, one should be fairly close and the last one would be dark.
Let say for this example, that 1/4th is too light, 1/8th is just about right, and 1/16th is a little too dark.

So, if the camera's largest f-stop is f2.8, the next level down might be f3.5. Using this setting, I'd try 1/4th second first. What was too bright, should now be just right. Moving up to the next f stop, f5.6, the setting for the shutter should now be 1/2 second. Moving up to f8, we are talking about 1 second...

Now, take these exposures taken at the different f stops, then view them on-screen. Pay careful attention to the what is in focus. At f2.8, the background should be a blur. At f8, the background should be sharp...

I recommend that everyone do this with their cameras when they get them so they can have some idea how it performs. Nothing beats testing the camera for getting a feel for its real performance. And given that, in this case, it is a digital camera, the cost is negligable.

Regards.
Mike Kirda

 

[Len]

One more idea that popped in my head: check the ISO you're using. If it's ISO 100, try ISO 400 to get sharper (although a bit more grainy pics).

 

[TS]

Try shooting in aperture priority mode, that way you pick the aperture and the camera selects the fastest possible shutterspeed given your lighting.

On my CP880 it's "A" on the mode dial.

Travis

 

[Anonymous]

Last three suggestions- testing, ISO, and aperture priority mode:

Good ideas! Thanks for the advice, all!

I'm stoked- by next week I should have my P-shop up and running again. I'm going to have to print this thread out so I can remember everything, and then spend some quality time with my fish tanks.

You know, I think it's time to get a few dwarf guaramis- the neat neon kind. Maybe some glass catfish and some cardinals to spice things up. This is for the FW tanks, of course, but should make for interesting pics as well.

Thanks a heap, guys! I will let you know the results.

 

[mountainbiker619]

hd,

What is your tank lighting and what have been the best settings on your 4300?

 

[Anonymous]

Wow, was this thread only in August? I feel like I have learned so much since then.

Tank lighting is 110watt PCs and 30watt NO actinic. I couldn't say it has "best settings" because they change for every shot. I don't take photos using ISO 400 because they suck major crap (IMO). I use 100 whenever possible. But a pretty common setting for me is f-2.8, 1/60 sec. for fish pics.

If I'm shooting corals, I will often decrease the shutter speed, and decrease the aperture to get better DOF.

HTH

 

[mountainbiker619]

hd,

What white-balance setting do you mostly use?

 

[Anonymous]

The auto is decent, but I found that setting it manually is best. I took a piece of white plastic, dunked it in the tank under the lights, then set my WB on it. It was the only way I could get a true tank-light white balance. Under my lights, the fluorescent setting 1 works pretty well too.

But, you can correct this pretty easily in Photoshop too.