A violet flower

[cristen]

Camera Canon EOS 500D
Exposure 0.067 sec (1/15)
Aperture f/5.6
Focal Length 53 mm
ISO Speed 100
Exposure Bias 0 EV
Flash Off, Did not fire

I love the color and the satiny texture of the petals. I also like the yellow radiating from deep within the (pistil). Your comments as to composition and camera settings are most welcome. And please, can someone also help me ID this flower? Thanks a lot.

[PaulE]

The flower's common name is morning glory and in some places it is considered a weed as it spreads quite rapidly. All in all a really beautiful flower. (Do a search on your search engine)
The flower's petals appear out of focus. Perhaps if you used a higher f-stop to get more of the flower in focus.
The composition and DOF I like except for the leaves under the flower. The one appears more in focus than the flower itself.
Hope this helps

[cristen]

Originally Posted by PaulE

The flower's common name is morning glory and in some places it is considered a weed as it spreads quite rapidly. All in all a really beautiful flower. (Do a search on your search engine)
The flower's petals appear out of focus. Perhaps if you used a higher f-stop to get more of the flower in focus.
The composition and DOF I like except for the leaves under the flower. The one appears more in focus than the flower itself.
Hope this helps

Thanks for your help, PaulE. I know about the morning glory but I was a bit confused because the leaves were quite large. I used to see them smaller. Now as for the settings, I have to agree with you that the focus is a bit off and the aperture, too. I am still so careless about the settings. Thanks, again.

[PaulE]

Hi Cristen,

Do a search for morning glory and you will find that a lot of flowers are categorised under that name. An excerpt from this page:
Morning Glory | The Flower Expert - Flowers Encyclopedia
Morning glories belong to different genera with slightly different floral, fruit and leaf characteristics. But all Morning Glories produce typical funnel-shaped blossoms in white, red, blue, purple and yellow.

Hope that clears up the bigger leaves?
Keep well
Paul

[cristen]

It did, PaulE... thanks. Have a nice day.

[chicagojohn]

Originally Posted by cristen

Camera Canon EOS 500D
Exposure 0.067 sec (1/15)
Aperture f/5.6
Focal Length 53 mm
ISO Speed 100
Exposure Bias 0 EV
Flash Off, Did not fire

I love the color and the satiny texture of the petals. I also like the yellow radiating from deep within the (pistil). Your comments as to composition and camera settings are most welcome. And please, can someone also help me ID this flower? Thanks a lot.

I read Paul E's comments, but on my monitor (and I looked also at the Flickr image) I don't see the petals to be that out of focus, actually.

First of all, technically, at 1/15 second (was this hand-held?? if so WOW), and a relatively low f/number, you could have gone up, say, 3 EV by increasing ISO to 800, probably without significant noise (and it could have been dealt with if present by a noisware program you can get a free version of). So that 3 EV would have bought you going from f/5.6 to maybe f/11 almost.

But then what would have happened to the relationship between the focus of the purple petals and the green leaves? Well, DoF increase would have reduced the difference between them. In my imagination, I think that would have made the image worser, not more betterer.

OK, so beyond that, when I see this, I love the fluidity of the purple petals and the dynamic range going on within them. It reminds me of flowing waves.

And then at the base of the flower, that light seems to be projecting upward and outward like a "shout-out" to the sun, sort of. And I just think that the whole composition works very well as regards light and color. Everyone is different in their perceptions, but that is mine for what it's worth.

As for the aperture idea, I would think it's problematic in this case because I think that a disjunction between petal focus and the background is important to how this image works.

[cristen]

Originally Posted by chicagojohn

I read Paul E's comments, but on my monitor (and I looked also at the Flickr image) I don't see the petals to be that out of focus, actually.

First of all, technically, at 1/15 second (was this hand-held?? if so WOW), and a relatively low f/number, you could have gone up, say, 3 EV by increasing ISO to 800, probably without significant noise (and it could have been dealt with if present by a noisware program you can get a free version of). So that 3 EV would have bought you going from f/5.6 to maybe f/11 almost.

But then what would have happened to the relationship between the focus of the purple petals and the green leaves? Well, DoF increase would have reduced the difference between them. In my imagination, I think that would have made the image worser, not more betterer.

OK, so beyond that, when I see this, I love the fluidity of the purple petals and the dynamic range going on within them. It reminds me of flowing waves.

And then at the base of the flower, that light seems to be projecting upward and outward like a "shout-out" to the sun, sort of. And I just think that the whole composition works very well as regards light and color. Everyone is different in their perceptions, but that is mine for what it's worth.

As for the aperture idea, I would think it's problematic in this case because I think that a disjunction between petal focus and the background is important to how this image works.

Hello again, CJ.

So, did this image work?

Yes, that shot was hand-held. I took this shot while on a short break during a seminar. I do have a tripod which I always carry around but, well, I find it cumbersome to set-up.

I don't know, but it's been my habit to use ISO 100 when taking outdoor or in the shade shots for fear of noise as I don't have any noise reduction program. Or if ever I download one, I still have to figure out how to use it. (Whew! And I have not even made considerable progress in Photoshop!)

Whenever I take pictures, I really forget about technical details and all. I just satisfy my eye for the beauty of what I see and take the shot. Is this wrong?

[chicagojohn]

Originally Posted by cristen

Whenever I take pictures, I really forget about technical details and all. I just satisfy my eye for the beauty of what I see and take the shot. Is this wrong?

I don't know if there is any "right or wrong" to any of this. But I don't think it hurts to understand the tradeoffs involved in EV (Exposure Value).

So, we all know that shutter speed is a tradeoff if we want to avoid camera shake or stop motion or maybe show motion as a blur.

In ISO, which in digital is amplification, higher iso and higher amplification can amplify noise and reduce the signal-to-noise ratio. But this isn't going to be much of a problem at ISO 800 or below and even above especially if you don't have large expanses of dark or uniform color like a sky. You can download a free version of a program like Noisware which is incredibly simple to use if this becomes a problem, which it shouldn't for a good DSLR such as you are using.

In aperture, the tradeoff is depth of field. Wider the aperture (lower the f/number), the less the depth of field. (The actual aperture diameter is the lens focal length divided by the f/number; e.g., for a 50 mm lens at f/2.0, the aperture would be 50/2 or 25mm, which is just about 1 inch diameter.)

So, right or wrong, I don't think it hurts to understand the strengths and weaknesses of each of these three ways of changing exposure value an knowing you can trade one exposure value in shutter speed, for example, for another one in aperture or iso, and vice versa.

1 EV is a doubling of light falling on the sensor. So in shutter speed, going from 1/15 to 1/30 is -1 EV. Going from 1/120 to 1/250 is -1 EV.

In ISO, going from 100 to 200 is +1 EV. Going from 400 to 800 is +1 EV.

In aperture, however, it varies with the square of the f/value. So the f-stop range is as follows in 1 EV units: 1, 1.4, 2, 2.8,. 4. 5.6, 8, 11, 16, 22, 32, 45, 64

So let's say you have a scenerio where the ideal exposure would be f/8 at ISO 200 and 1/60 shutter speed. But you want to minimize depth of field to highlight the focus of a flower (in focus) against the background (more out of focus).

So if you were to go to an f/2.8 (maybe the minimum your lens has available) that would be a change of plus 3EV units; it is three units over from f/8 to f/2.8 in the above list, a larger aperture and more light to the sensor. So to maintain exposure -- the amount of light falling on the sensor -- you would have to compensate with -3EV in exposure or ISO. You could get 1EV in a positive direction (less noise) by reducing ISO from 200 to 100. That may be as low as you can go in ISO (amplification). You could get another -2EV, again in a positive direction by going from 1/60 to 1/250 in shutter speed (less chance of camera shake or flower motion if you happened be shooting a rapidly growing plant)

So as an example, that's what I'm getting at. Each of these three have advantages you might want to maximize in any given situation. So swapping EV's you can trade off one against another to get what you want. Not that there is any "right or wrong" just choices you can see and use versus ignorance.

That's my story, and I'm stickin' to it....

[cristen]

This is a long read, CJ.I've bookmarked it coz I will be learning a lot from this. I took a pic this afternoon, keeping in mind the higher ISO so I can use a higher shutter speed, but forgot to adjust the EV again. My camera only has (+) and (-) 2 and I must admit, up to this time, I am still familiarizing myself with my camera.

I really appreciate your help, CJ. You are so patient in explaining every technical detail.

I posted the picture in the weekly assignment and maybe you can spare a comment or two.

[chicagojohn]

Originally Posted by cristen

but forgot to adjust the EV again. My camera only has (+) and (-) 2 and I must admit, up to this time, I am still familiarizing myself with my camera.

I'll look at your assignment picture, but while your camera has something called an EV compensation setting that you can change +/-, what I am talking about isn't that.

I'm talking about the EV values for shutter speed, ISO, and aperture. Without regard for the EV compensation setting, what I'm saying is that each of the three processes -- shutter speed, ISO, and aperture -- have their effects on the image. These are, respectively, motion/blur, noise, and depth of field.

So by understanding how settings on each of these are related to exposure value, and thinking about the effects you want to obtain in a specific image, you will then be able to determine how to optimize the three settings to get the best result with a proper exposure. Exposure Value is another way of saying 1 "stop". Going from f/8 to f/11 is one stop. Going from ISO 200 to ISO 400 is one stop. Going from 1/250 to 1/60 s shutter speed is two stops. Or substitute "EV" for "Stop". So you can balance one against another to get the freeze/motion, noise level, and depth of field you want.

That's it in a nutshell.