Usage of quick shutter speed/high ASA

[Gno]

Newbie question,

I was toying with my camera yesterday and out of curiousity tried using the high speed option to snap pictures without using the flash. I found that in "Auto" mode, the pics were blurred due to insufficient light. However, when I used the high speed option, the pics were of much better quality.

As such, I'm curious if the same will work underwater. (this question arises coz I dun have an external strobe).

Anyone tried this before?

Just curious!!


Appreciate any advice/comments!!!

 

[ssra30]

I think I need a little clarification, first , are you using digital or film camera?
Usually the higher the ASA/ISO the more grain you are going to get with picture. If you are using digital camera, I would not use anything beyond 100 (at least with the Oly digital). I don't really know much about film.
Also, when you say highspeed option, do you mean you use a shutter priority mode (rather than auto, manual or aparture priority mode)?
At least on my Oly digital, when in auto mode, the camera seems to pick the widest aparture ie F 2 or 2.8, and fast shutter speed.
Generally if you don't have enough light, the picture is just dark. If it is blurred, it is either the camera could not focus (happen often in low light situation) or the shutter speed is too slow and you could not hold the camera still for the duration (usually I try not to have shutter speed slower than 1/80 second or 1/60-if I feel lucky) or if it is a picture of a fish, you can get motion aritfact (blurriness) if the shutterspeed is too slow, to get a still picture of most fish, the shutterspeed should be at least 1/100 or faster.
When you say that you get better result with high speed option, my guess would be that the blurriness is from motion artifact either by you or the subject from too slow a shutterspeed.

 

[Gno]

Gosh ssra30,

I feel like a total dufus. Most of what you said sounded greek to me!!!

I'm using a digital camera (3.2m).

Also, when you say highspeed option, do you mean you use a shutter priority mode (rather than auto, manual or aparture priority mode)?
Yes, thats what I meant from a newbie point. (I was told that a faster shutter speed like taking pics for Formula 1 cars would ease the lack of light concerns).

After, reading the entire post, I think you are right in that my problem lies with the moving object I'm trying to take i.e. motion artifact

My curiousity stemmed from the view (I'm probably wrong here) that if the shutter speed is fast and the ASA is high, I wouldn't have too much problem with moving objects or where there is low light! (limited experience from my old film camera).

Thanks a lot ssra30!!!

 

[ssra30]

Alright, we are getting warm here here is a few basic things.

When you use faster shutter speed, you will actually need more light ie 1/400 second will be darker than the same picture taking at slower shutter speed eg 1/60 second.

Using higher ASA/ISO such as ISO 400 will make the picture brighter than 100 but at the cost of noise. You will get more grain in the picture.

To take picture with low light, what you want to do is open the aparture wider eg F4 instead of F8.
If you want to use semi automatic mode, aparture priority is probably better. Just select whatever aparture you want, generally around F5.6 and see what the camera select for shutterspeed. Again, shooting moving fish, you want to make sure that the shutterspeed is 1/100 or faster, if shutterspeed is too slow, just decrease the F-number (open the aparture more) Don't forget the smaller the fraction number eg 1/400, 1/1000 the faster the shutter speed.
Remember though, the wider the aparture (smaller the F number)
the smaller the depth of field you are going to get (minumum and maximum distance where things will be in focus). Not too big an issue with digital camera when you are in normal mode but become more important in macro mode.

Well, hopefully this sounds a bit less like Greek

 

[Gilligan]

Gno you may want to check out this site as it is very helpful in the use of manual versus auto settings underwater. Even though the site is for the Olympus 5050 camera the info applies to other digital cameras. I have found that using manual settings gives far better results than the auto ones underwater. ssra30 has given you good info. Don't forget you are not using a strobe and your built in flash underwater is good to about 3 feet max., so you have to factor that into your equation. One thing I am trying, and it seems to work, is to set my internal flash on it's max setting (+2.0 on the Oly C4000) which allows me to use slightly higher F stops and faster shutter speeds than on the normal flash setting of 0.0.

 

[Gno]

ssra30,

Aaaaaaarrr!!!!!!!!!!

I will digest what you have posted over the weekend and will revert if I have any further queries!!!

Now I can safely say I know slighty more about the shutter speed stuff.!

Thanks a lot!!!

Giligan,

Thanks for the tip too!!!!

PS: At the rate things are going, I think I might as well change to the Oly from my current Canon S30!!! More stuff on the Olys than Canon!!;-0

Gno

 

[andrea31419]

Thanks...I've learned something too. I'll be practicing this weekend with my Olym C4000Z.

A.

 

[Cecil]

Gno, I'll give you the short answer. Use the higher ASA underwater, unless there is a lot of natural light. You will get more noise but that is better than motion blur. I lose more pictures to motion blur than just about anything else.

 

[g8trdiver]

The techniques for good exposure should be the same for Digital and Film.

Any good photography reference (class, book, website) will teach the basics of getting the right amount of light on your "target" (film or chip). Even the concept of graininess translates in both worlds.

The nice thing about digital that you don't have with film is the white balance.

Otherwise, pretty much all of the concepts you can learn about photography can be achieved on either medium.

Another nice thing about digital: Trial and Error is much less expensive! Just hit "delete".

Have fun experimenting!!!

 

[blacknet]

Hello,

A few quick comments.

I found that in "Auto" mode, the pics were blurred due to insufficient light.

After, reading the entire post, I think you are right in that my problem lies with the moving object I'm trying to take i.e. motion artifact

First off your pics will NOT blur to do insufficient light, that's just a myth. Repeat after me, light is light is light. The reciprocal rule applies in this case. It states for hand holding when your shutter speed is slower than 1/focal length of the lens then you will get camera shake, i.e. our moving body whether it be motor control, heart beat, nerve movements etc... "A" modes do not take this into account; it's up to the photographer to do that. NOTE: if you have an IS lens this rule still applies but with some serious modifications.

A low light motion shot presents its own challenges. In the afternoon's we switch to 400 iso film and in most cases that is sufficient. This is where strobes come into play, to fill flash the moving subject(s) but never use strobes on aquatic mammals or deep sea creatures.

If you went to the tips/techniques section you can read the article I wrote about camera modes and numerous techniques on dealing with these problems.

Ed