Monday, May 21, 2018

Expose Your Triangle - Shutter Speed

It's called the Exposure Triangle....and seems to be one of the most confusing things in photography although it shouldn't be!  I've included graphics for linear and circular thinkers...something for everyone!

So, what is it anyway? The exposure triangle is three settings that go hand-in-hand that let you create amazing photos: ISO, Shutter Speed, and Aperture.

Today, I'll cover Shutter Speed. You can think of this in terms of 'how fast can you blink' and 'how much can you see when you blink fast vs slow.'

Shutter Speed is about movement and what movement or stillness you can capture by adjusting the setting.

If you blink fast, things tend to stand still, to be stationary. If you blink slowly (keeping your view straight ahead as your camera does), things tend to pass through your vision quickly and often at a blur.

The important principle to remember when you are changing shutter speed is that a fast shutter speed will freeze action but also lets in a lower amount of light. You will need a bright setting or additional lights to capture and freeze the action.

A slow shutter speed allows for blur of a moving object but lets in a greater amount of light.

Here are a couple of examples. I was playing around with long exposures (usually considered to be longer than one second!) and took these on my street. I wanted to capture the light trails of cars driving down the road.

These are completely unedited, taken July 27, 2017 at 9:58 pm. I was just behind the red truck parked on the street and had the camera mounted on a tripod. An FYI here: if you are shooting anything that's lower than 1/60 second shutter speed, it's advisable to use a tripod.



Headlights of approaching vehicle
F22
30 seconds
ISO 100
Focal Length 18mm
(the lens goes from 18-55 mm)






Headlights of approaching vehicle
F22
7.7 seconds
ISO 100
Focal Length 18mm
(the lens goes from 18-55 mm)




You can see how much additional light was let in with the longer exposure. Had I taken a regular shot at 1/60 or faster shutter speed, the photo would have been completely blacked out due to lack of light.

You can play with this by taking your camera to a busy street or a playground with lots of kids. Take a few shots at different shutter speeds and notice how the high shutter speeds freeze action but are usually darker, and the low shutter speeds show blurry subjects (cars/kids) but are quite a bit brighter.

Here are those Exposure Triangle charts again for your convenience.













Sunday, April 15, 2018

Expose Your Triangle - Aperture

It's called the Exposure Triangle....and seems to be one of the most confusing things in photography although it shouldn't be!  I've included graphics for linear and circular thinkers...something for everyone!

So, what is it anyway? The exposure triangle is three settings that go hand-in-hand that let you create amazing photos: ISO, Shutter Speed, and Aperture.

Today, I'll cover Aperture. Ninety-nine percent of the time, I shoot in Aperture Mode on my Nikon D3200 because my general area of interest is floral closeups and landscapes - talk about being on opposite ends of the spectrum! - so I do a lot with Depth of Field.

Aperture is the size of the opening of your lens. I'll not go into what all the stops mean, but aperture is measured in f-stops.  It seems counter-intuitive, but low number = wide open lens, high number = very small opening in lens.

Depending on your lens, it can be a very low number (wide-open) f1.4 or very high number (barely open) f32.  Think of it like a cat's eye:

When the pupils of a cats eyes are wide open, they let in a lot of light that allows them to see in the dark. A wide open lens also lets in more light and takes better photos indoors or in low light.

When the cat's pupils are narrow slits, usually when the environment is very bright. Just like an f32 setting, they let in very little light because the area is bright. Too much light - over exposed photos - lose most of the detail, it's just too bright. (Conversely, an under-exposed photo is one where there was not enough light.)


Wide open pupils - Aperture small number i.e. f1.4, f2.3, f3.4, etc. - lets in a lot of light. Blurs the background (called bokeh).
Nearly closed pupils - Aperture large number i.e. f24, f32, etc. - lets in a small amount of light. Focuses the background.


(These are NOT my cat photos.)




Aperture controls that mysterious thing called Depth of Field which represents 'how far can you see clearly and in detail?" and applies to your background.

If you want a closeup of a flower in your garden and a blurry background (called 'bokeh'), or if you are shooting in a dim indoor setting, you will want an aperture number that is a small number but wide opening that lets in lots of light, say f1.8 or f2.8.

If you want your background to be in detail - as you might with a landscape shot with meadow in the foreground and mountains in the background -  you will want an aperture number that is pretty high such as f18, f22, etc. It sees clearly at a distance.

Note that not all lenses offer all apertures! When looking at a zoom lens, for example my Nikkor 55-200mm, says on the box f/4-5.6. This means that at 55mm the smallest aperture (widest opening) this lens can provide is f4, and zoomed out to 200mm the smallest aperture this lens can provide is f5.6. On the narrow side (high number, tiny opening), 55mm will go to f22, and 200mm will go to f32.

The best way to understand aperture is to play with it. I have taken my camera set up on a tripod and taken photos of the exact same subject at different f-stops, starting with wide open (low number) and going to very small opening (high number), then comparing the clarity of the backgrounds. This is best done outdoors where you have some distant details to work with, like down the street, or out in nature with hills/mountains in the background. It's a great way to learn what the different stops do, and really shows the meaning of  'depth of field.'

You can see why it's important to have an idea of what you want to shoot before you purchase a lens. Will you be shooting indoors or in low light, or outside in bright light? Do you want closeups or wide angles? A lot of detail throughout your photos, or an artistically blurry background (bokeh) with your subject in perfect clarity and detail? 

Next time, I'll cover another aspect of the exposure triangle. Meanwhile, here are a couple of diagrams to help.

















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Friday, March 30, 2018

If you're not editing your photos, why shoot in RAW?

This is a question I saw the other day in one of the Facebook photography groups I belong to, and it got me to wondering, so I asked:

* Is there any value taking photos in RAW then converting to JPG as opposed to just shooting in JPG if you're not going to edit?

* Is there any value in comparing RAW to JPG as a personal educational tool? (How different are they, really, if you're shooting in, say, Aperture Priority as I do?)


About RAW and JPG:

If you haven't noticed already, your DSLR can save photos onto your SD Card in two formats: RAW and JPG. It can also save them in both formats simultaneously which is what I do. (Consult your camera's owner's manual for how to set the output formats.)

For folks who are taking photos to share online or send to friends, JPEG is good enough. If you want to get into the editing and/or artistic areas of photography, or printing your photos, you really want to be shooting in RAW.

Part of the reason is this: JPG format is edited by and in your camera, and only minimal editing is available afterwards. RAW is not edited in camera at all. You have far more ability to be creative within your editing software.


My questions were answered by one of the fellows who posted this link to the group.

RAW vs JPG Overview


It includes a 10-minute video and an article with photo examples of the differences, and the different capabilities allowed, when processing and editing JPG and RAW files.