deviantART: by:SparkyArt

deviantART: by:SparkyArt http://search.deviantart.com/?q=by:SparkyArt&section=today deviantART RSS for by:SparkyArt en-us Copyright 2009, deviantART.com Wed, 09 Dec 2009 21:13:12 PST deviantART.com http://blogs.law.harvard.edu/tech/rss http://s.deviantart.com/minish/widgets/apple-touch-icon-precomposed.png Well it's Happened - I'm Moving http://SparkyArt.deviantart.com/journal/17776652/ http://SparkyArt.deviantart.com/journal/17776652/ Thu, 10 Apr 2008 08:57:42 PDT
New Account:

]]> ~SparkyArt What Is... Aperture? http://SparkyArt.deviantart.com/journal/17764032/ http://SparkyArt.deviantart.com/journal/17764032/ Wed, 09 Apr 2008 13:17:18 PDT

When you look at the technical specifications of a digital camera, one of the very first specification mentioned is its maximum aperture and/or its aperture range.

What is 'aperture,' what is a good aperture range, and how is aperture relevant when it comes to choosing a digital camera?

What Is Aperture?

The main function of a camera lens is to collect light. The aperture of a lens is the diameter of the lens opening and is usually controlled by an iris.The larger the diameter of the aperture, the more light reaches the film / image sensor.

Aperture is expressed as F-stop, e.g. F2.8 or f/2.8. The smaller the F-stop number (or f/value), the larger the lens opening (aperture).

[Note: Many camera user manuals today will refer to the aperture in terms of "aperture value" instead of f/value. I'm not sure when this trend started but don't get confused between "aperture" and "aperture value." Aperture value" is simply another way of saying f/value.]

In practice, unless you are dealing with a fixed-aperture lens (many simple point-and-shoot cameras have only one fixed aperture), the aperture of a lens is usually expressed as a range of fstops.

When you read the specifications of a camera, the aperture may be expressed in a number of different ways, the following three being the most common:

* Maximum Aperture:

Max. Aperture F2.8

This simply states that the maximum aperture for the lens is F2.8.

* Aperture Range:

Aperture Range F2.8-F8.0

This states the max. and min. aperture, the assumption being that there are standard increments between them.

* Maximum Wide-Angle and Telephoto Apertures:

Aperture F2.8-3.5 or F2.8(W)-F3.5(T)

This gives the max. aperture for the wide-angle (F2.8) and telephoto (F3.5) focal lengths of a zoom lens.

It is usually not too difficult to figure out that a stated range deals with maximum apertures and not max and min apertures: the mimimum aperture should be quite small at F8, F11, F16 or F22.

A "fast" lens is one that has a large maximum aperture (F2.4, F2.0 for current digital cameras; F1.4, F1.2 for 35mm film cameras).

A Good Aperture Range

My personal preference for a 'good' aperture range is:

F1.8 - F16
F1.8 F2.8 F4 F5.6 F8 F11 F16

This tells us that the camera has an aperture range of F1.8 to F16; the maximum aperture is F1.8, and the minimum aperture is F16.

There are 5 f-stops between the max and min aperture. If your camera's lens is currently set at an aperture of F5.6, closing it by 1 f-stop would mean selecting F8; opening it up by 1 f-stop would mean selecting F4.
F1.8 F2.8 F4 F5.6 F8 F11 F16

How Is A Large Maximum Aperture Relevant?

A large maximum aperture is preferable to a smaller one since it gives the photographer more latitude in the kind of pictures that can be taken.

For example, it is pretty obvious that the larger the aperture, the better your digital camera will perform in low-light situations, since a larger lens opening is able to admit more light than a smaller lens opening.

A larger max. aperture also allows you to use a faster shutter speed to freeze action.

So, let's say the light meter in your digital camera calculates that for proper exposure in that indoor arena, you need an aperture of F4 and a shutter speed of 1/60 sec.
F4
1/60

To use a faster shutter speed (say, 1/250 sec.) to freeze action, you have to open up the aperture to allow more light in for that shorter amount of time.

For every shutter speed increment we go up, we need to open up a f-stop of aperture. From 1/60 sec. to 1/250 sec. there are 2 increments, so we open up the aperture by 2 f-stops, going from F4 to F1.8. Note that the camera would give proper exposure at 1/60 sec. at F4, 1/125 sec. at F2.8, and 1/250 sec. at F1.8, since all three aperture/shutter speed combinations allow the same amount of light into the camera. [Some digital cameras provide a '

rogram Shift' function to allow that very shifting of aperture/shutter speed combinations in tandem.]
F1.8 F2.8 F4 F5.6 F8 F11 F16
1/250 1/125 1/60 1/30 1/15 1/8 1/4

Of course, in a digital camera set on Auto mode, you can select Sports scene mode, and the camera will automotically select a fast shutter speed and the appropriate aperture. Likewise, in Shutter-Priority mode, you can choose which shutter speed you want (fas... ]]> ~SparkyArt What is ISO? http://SparkyArt.deviantart.com/journal/17594310/ http://SparkyArt.deviantart.com/journal/17594310/ Sun, 30 Mar 2008 17:40:07 PDT
ISO sensitivity expresses the speed of photographic negative materials (formerly expressed as ASA).

Since digital cameras do not use film but use image sensors instead, the ISO equivalent is usually given.

What ISO denotes is how sensitive the image sensor is to the amount of light present. The higher the ISO, the more sensitive the image sensor and therefore the possibility to take pictures in low-light situations.

And, where you would have needed to physically change to a different roll of film if you wanted a different ISO speed, digital technology allows you to simply dial one in. In this way, you can record images taken at different ISO speeds on the same memory card.

ISO Speed & Exposure

ISO speed affects the shutter speed / aperture combinations you can use to obtain correct exposure.

Suppose your digital camera's light meter warns you there is not enough light to correctly expose a scene. You could use the on-board flash, but let's suppose again it's not allowed (like in a concert or indoors recital).

You would then need to use a higher ISO. Set on "ISO Auto" mode, your digital camera will automatically select a higher ISO. Otherwise, you can manually select the next higher ISO and see if the increased sensitivity allows you to obtain a correctly exposed picture. If it does, you can now take a correctly exposed picture.

Similarly, if you find the camera is using a shutter speed that is too slow (1/60 sec. and slower) to handhold the camera steady and shake-free (thus resulting in blurred pictures), and you cannot open up the aperture anymore, and you do not have a tripod or other means to hold the camera steady, and you want to capture the action, etc. etc. -- then you might select the next higher ISO which will then allow you to select a faster shutter speed.

ISO Speed & Noise

However, all this increase in sensitivity does not come free. There is a price to pay with your image appearing more noisy.

See, when you boost the sensitivity of your image sensor by selecting a higher ISO, the image sensor is now able to record a fainter light signal. However, it is also true now that it will record fainter noise, where noise is any signal that is not attributed to the light from your subject. Remember that an image sensor is still an analog device and it generates its own noise, too! The increased sensitivity allows the image sensor to record more light signal and more noise. The ratio of light signal to noise (S/N ratio) determines the "noise" in your resultant image.

An image sensor is usually calibrated so that it gives the best image quality (greatest S/N ratio) at its lowest possible ISO speed. For most consumer digital cameras, this value will be expressed as ISO 50, ISO 64 or ISO 100. A few digital cameras use ISO 200 as their lowest ISO speed.

Just as with its film counterpart, an image sensor will exhibit "noise" (comparable to "graininess" in film) at the higher ISO speeds. Unlike film, where graininess can sometimes contribute to the mood of the image, noise produced by an image sensor is undesirable and appears as a motley of distracting coloured dots on your image.

ISO Speed & Image Sensor Size

The size of the image sensor determines the ISO speed range that a digital camera can use without suffering from undue noise. One reason for this is because the pixels on the larger image sensor can be larger and therefore receive more light, and thus have a greater signal-to-noise (S/N) ratio.

Most consumer digital cameras use 1/1.8 in. (and smaller) image sensors, so noise at high ISO is a problem. Though they will allow you to use a high ISO (such as ISO 400), the resultant image will usually be very noisy.

A digital SLR (dSLR), on the other hand, uses a large image sensor, usually full frame (24x36 mm) or APS-sized (half-frame). Noise is rarely a problem and the use of a high ISO 400 results in images with barely noticeable noise.

Practical Considerations

You obtain the best image quality by using the lowest ISO possible on your digital camera. If you want to ensure your digital camera always uses the lowest ISO setting, switch the ISO setting from the default "Auto ISO" (this setting is usually found in the Menu) to the lowest possible on the camera, say ISO 50.
If you mostly take pictures where there is enough light for a correct exposure, i.e. sunny outdoors, then using the lowest ISO on your digital camera will give you the best image quality your digital camera is capable of.
If you want to take pictures indoors where light may not be sufficient an... ]]> ~SparkyArt Horsography for Sale http://SparkyArt.deviantart.com/journal/17163099/ http://SparkyArt.deviantart.com/journal/17163099/ Mon, 03 Mar 2008 11:19:42 PST
]]> ~SparkyArt Dear Dogs & Cats: http://SparkyArt.deviantart.com/journal/17105155/ http://SparkyArt.deviantart.com/journal/17105155/ Thu, 28 Feb 2008 15:46:30 PST The dishes with the paw prints are yours and contain your food. The other dishes are mine and contain my food. Please note, placing a paw print in the middle of my plate and food does not stake a claim for it becoming your food and dish, nor do I find that aesthetically pleasing in the slightest.

The stairway was not designed by NASCAR and is not a racetrack. Beating me to the bottom is not the object. Tripping me doesn't help because I fall faster than you can run.

I cannot buy anything bigger than a king sized bed. I am very sorry about this. Do not think I will continue sleeping on the couch to ensure your comfort. Dogs and cats can actually curl up in a ball when they sleep. It is not necessary to sleep perpendicular to each other stretched out to the fullest extent possible. I also know that sticking tails straight out and having tongues hanging out the other end to maximize space is nothing but sarcasm.

For the last time, there is no secret exit from the bathroom. If by some miracle I beat you there and manage to get the door shut, it is not necessary to claw, whine, meow, try to turn the knob or get your paw under the edge and try to pull the door open. I must exit through the same door I entered. Also, I have been using the bathroom for years --canine or feline attendance is not required.

The proper order is kiss me, then go smell the other dog or cat's butt. I cannot stress this enough!

To pacify you, my dear pets, I have posted the following message on our front door:

To All Non-Pet Owners Who Visit & Like to Complain About Our Pets:
1. They live here. You don't.
2. If you don't want their hair on your clothes, stay off the furniture. That's why they call it "fur"niture.
3. I like my pets a lot better than I like most people.
4. To you, they are an animal. To me, he/she is an adopted son/daughter who is short, hairy, walks on all fours and doesn't speak clearly.

Remember: Dogs and cats are better than kids because they:

1. Eat less
2. Don't ask for money all the time
3 Are easier to train
4. Normally come when called
5. Never ask to drive the car
6. Don't hang out with drug-using friends
7. Don't smoke or drink
8. Don't have to buy the latest fashions
9. Don't want to wear your clothes
10. Don't need a gazillion dollars for college, and...
11. You don't have to pay for their wedding
12. And If they get pregnant, you can sell their children

]]> ~SparkyArt ~ Update ~ http://SparkyArt.deviantart.com/journal/16896162/ http://SparkyArt.deviantart.com/journal/16896162/ Fri, 15 Feb 2008 09:30:54 PST
]]> ~SparkyArt Print Requests http://SparkyArt.deviantart.com/journal/16462128/ http://SparkyArt.deviantart.com/journal/16462128/ Fri, 18 Jan 2008 15:53:24 PST
]]> ~SparkyArt A New Leaf for a New Year http://SparkyArt.deviantart.com/journal/16192251/ http://SparkyArt.deviantart.com/journal/16192251/ Mon, 31 Dec 2007 19:43:41 PST
]]> ~SparkyArt Clean Up http://SparkyArt.deviantart.com/journal/15436875/ http://SparkyArt.deviantart.com/journal/15436875/ Fri, 09 Nov 2007 16:03:36 PST

Well, it's been a while since
Damn, it sucks so bad that DA doesn't make it easy to clean up your deviations. I wish you could click a box, and choose wher eyou want to put them. Out of all the stupid things you barely use on DA, this could be most useful. Anywho, I'm out of school now for three weeks so, hopefully some inspiration will come...

This weeks featured artist is ElectronicRainbow

Requests

Closed...

Thanks for Visiting!

]]> ~SparkyArt Featured Artists: Cats http://SparkyArt.deviantart.com/journal/15126729/ http://SparkyArt.deviantart.com/journal/15126729/ Fri, 19 Oct 2007 09:33:46 PDT
For those of you who love cats, and want to check out some awesome photographs, here are some great one's out there that I know you would love to check out!

]]> ~SparkyArt Featured Artist: Artphr33k http://SparkyArt.deviantart.com/journal/15070839/ http://SparkyArt.deviantart.com/journal/15070839/ Mon, 15 Oct 2007 09:45:25 PDT
Have you ever wondered just how some of the people in our DA community just do the things that they do? Well, here is my featured artist for this week. Her name is Artphr33k and her illustration skills are beyond imagination...The skills behind the artwork is unimaginable and shows a lot of time and patience has gone into all of her art work. I would love for all of my friends and just passer byers to check her art out, it's amazing!

Here are some samples of

]]> ~SparkyArt James Martin, RIP my brother http://SparkyArt.deviantart.com/journal/14811188/ http://SparkyArt.deviantart.com/journal/14811188/ Thu, 27 Sep 2007 09:23:28 PDT
OCALA - James E. Martin may have been only 11 years old, but he was wise beyond his years.

"He always seemed to know much more about life and people than someone his age should," his mother, Catherine Martin, said Monday. "He felt things more than anyone I think I've ever known . . . He was an old soul."

James died Sunday night at Shands Hospital in Gainesville, a day after he was hit by a van as he attempted to cross County Road 467 near his school, Belleview-Santos Elementary.

James apparently ran or skateboarded into the path of a 1993 Dodge Caravan driven by Eugenio Serano, 46, of Ocala, around 7:50 p.m. Saturday, said Lt. Mike Burroughs of the Florida Highway Patrol.

"It appears that the . . . child ran out in front of the truck, just didn't see it," Burroughs said.

Catherine Martin was on her way home, having stopped at Wal-Mart after work, when she drove up on the accident scene.

"God brought me there," she said. "I could see the cars were stopping. I didn't know what it was. . Some spiritual thing physically lifted me out of the truck, and I was running, and I was saying 'God, no, not my child, not my child."

Paramedics took James to Munroe Regional Medical Center, and he later was flown to Shands. A neurosurgeon told Martin her son was brain dead, but his strong young heart kept beating. She knew what James would have wanted, she said.

"James would have wanted his heart to go to somebody. He was a giver," she said. "I wanted that part of him to live on."

Martin donated her son's organs to enable others to live.

"That's James' gift, to give another child a chance at a healthy life," she said. "I feel that nothing but good can come from this."

Martin described her son, born April Fool's Day 1996, as a "diamond in the rough." He was a happy optimist, she said.

"He looked to the light, and looked to the brightness," she said. "He found beauty in everything. . . He appreciated being given the opportunity to do the things that he did."

James loved sports, including football and competitive running. He shared his enthusiasm with the family's two Weimaraners, Pepper and Jay.

"He just loved them to death," his mom said. "He used to jump on the trampoline with them."

He loved music and video games, and the combination of the two.

"He picked up a guitar a couple of years ago and just started playing it," Martin said. "He loved Guitar Hero."

In a family that has seen tragedy in recent years, James was a source of comfort. His father died suddenly three and a half years ago while on a trucking run out of state.

"He helped me. He was my strength. He was my life," Martin said of her son.

Catherine Martin's mother, Nancy Louise Coate, died Sept. 5. James was at her bedside.

"He said, 'Nana, I'm here for you, and I know what you're going through, because my dad went through it, and he's in heaven with the light,'Ã" Martin said. "He was just so loving."

James was a fifth-grader at Belleview-Santos. Principal Troy Sanford got to know James last year, Sanford's first at the school.

"Those big brown eyes would always sparkle, and he was eager to help," Sanford said. "There was nobody that James didn't like, and nobody didn't like James."

In addition to his mother, James is survived by his sister, Jessica, 13, and two brothers, Michael, 20, and William, 23, and other family members.

As of Monday evening, James' organs had gone to at least four other people, helping to save lives. His mother believes that's what he would have wanted.

"I want this to be his cause, and his purpose," she said. "His organs are going to live on. He hasn't, in a sense, left us. He is still with us."

This was my brother, rest in peace.

]]> ~SparkyArt I was Featured! http://SparkyArt.deviantart.com/journal/13597261/ http://SparkyArt.deviantart.com/journal/13597261/ Tue, 03 Jul 2007 19:37:08 PDT
[link]

So fave it! Love it! Watch it! yea! ]]> ~SparkyArt Requests? http://SparkyArt.deviantart.com/journal/13261617/ http://SparkyArt.deviantart.com/journal/13261617/ Fri, 08 Jun 2007 06:21:38 PDT
]]> ~SparkyArt New DA Page http://SparkyArt.deviantart.com/journal/12838054/ http://SparkyArt.deviantart.com/journal/12838054/ Fri, 04 May 2007 09:25:33 PDT
]]> ~SparkyArt About Me http://SparkyArt.deviantart.com/journal/12742711/ http://SparkyArt.deviantart.com/journal/12742711/ Thu, 26 Apr 2007 13:16:58 PDT

]]> ~SparkyArt Hits Grand Prix http://SparkyArt.deviantart.com/journal/12247804/ http://SparkyArt.deviantart.com/journal/12247804/ Mon, 19 Mar 2007 16:33:33 PDT
CHECK THEM OUT!

]]> ~SparkyArt YAYNESS http://SparkyArt.deviantart.com/journal/12065530/ http://SparkyArt.deviantart.com/journal/12065530/ Mon, 05 Mar 2007 10:04:19 PST
]]> ~SparkyArt Maybe http://SparkyArt.deviantart.com/journal/10981777/ http://SparkyArt.deviantart.com/journal/10981777/ Thu, 07 Dec 2006 09:29:37 PST
]]> ~SparkyArt Wow http://SparkyArt.deviantart.com/journal/10598033/ http://SparkyArt.deviantart.com/journal/10598033/ Thu, 02 Nov 2006 20:41:10 PST
]]> ~SparkyArt Update http://SparkyArt.deviantart.com/journal/10408318/ http://SparkyArt.deviantart.com/journal/10408318/ Mon, 16 Oct 2006 03:49:36 PDT
]]> ~SparkyArt A Thousand Different Ways http://SparkyArt.deviantart.com/journal/10123601/ http://SparkyArt.deviantart.com/journal/10123601/ Tue, 19 Sep 2006 15:24:32 PDT ~SparkyArt How Come Everytime You... http://SparkyArt.deviantart.com/journal/9944482/ http://SparkyArt.deviantart.com/journal/9944482/ Sat, 02 Sep 2006 19:56:15 PDT

Check it out!

my buddy!

Support the Bunneh or DIE! ]]> ~SparkyArt