Understanding F-Stops

Definition

F-Stop is a unit to express how much light is entering a camera lens. Example f/2, f/4, f/8, etc.

Explanation

Assuming this post is for beginners I am briefing out the dependent terminologies:

Aperture: Just like our eyes, camera lens has an opening that allows light to enter into the camera. This opening is termed as aperture.

Focal Length: Distance between the image sensor and optical center of camera lens. When you buy a lens for your camera, it will have a number on it, something like 18mm, 55mm, 105mm, etc. These numbers are called as focal length.

Letter “F” in F-Stop is called as focal length. Focal length divided by aperture determines the F-Stop.

Calculating F-Stop

For a 200mm lens with an aperture 50mm:

F Number = Focal Length/ Aperture

= 200/50

= 4

Finally denoted as F/4

For a 200mm lens with an aperture 25mm (decreasing the opening):

F Number = Focal Length/ Aperture

= 200/25

= 8

Finally denoted as F/8

Focal Length	Aperture	F-Stop	Conclusion
200 mm	50 mm	F/4	Bigger lens opening results in smaller F-Stops More light enters when F-Stop is small
200 mm	25 mm	F/8	Smaller lens opening results in bigger F-Stops Less light enters when F-Stop is large

How does this affect your photography?

Change in f number has a…….

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Protecting your Camera’s Sensor from Dust

Just like many of you I am also a believer of “Prevention is better that cure”. If you can prevent your camera’s sensor from getting dusty, you will never have to look for a cure. Here are a couple of important steps you can avoid getting dust into your camera:

- Keep you camera clean. If you can; avoid working in dusty areas.

- After shooting store your camera in a clean bag i.e. free from dust.

- Keep your replacement lens ready before changing the lens. This will at least reduce the time of exposure of your camera’s optics to dust. I have seen people first removing the lens, keeping it aside, grabbing another lens from deep inside of their bag while keeping the camera optics exposed to dust. I personally call it “abusing”.

- Before replacing make sure you dust off the rear of the lens mount of the replacement lens.

- While detaching the lens, face the camera downwards so that any dust particles present in the mirror chamber fall away from the sensor not on the sensor.

- After you have attached replacement lens, put back the end cap quickly on the last lens so as to reduce the dust that might fall on it.

- User blower bulb to dust off your optics. Never ever user compressed air or vacuum.

- Blow off dust before every session else you will have to curse yourself for returning home with those tons of photos containing dust spots that were present on you sensor before you even started.

- If available use your camera’s dust reduction feature. You can specify when to run this feature automatically i.e. at the startup or at the time you shut off your camera. I prefer to run the mechanism at startup as well as at the time of shutting off. The dust reduction mechanism basically produces vibrations on or around the image sensor making dust particles fall off.

Choosing a DSLR (Part-II)

In my last post “Choosing a DSLR (Part-I)” I explained one of the 5 steps that I would recommend to choose a DSLR. In this post I’ll emphasize on the remaining steps.

2. Getting familiar with the important features.

In the previous step I only stated the feature that you will be looking in your new DSLR. Let me brief out the features along with some common specifications.

1.1. Image Stability- One of the most important features you will like to have in your DSLR. This feature is required in almost all the available scenarios and comes in two ways these days; one integrated with in the camera body and other in the lenses. When activated minor tremble to the camera will be eliminated resulting in sharper, crispier images even in the darker conditions. Some manufacturers term it as “Vibration Reduction” and some call it “Image Stabilization” but both means the same.

1.2. Sensor Size- Basically larger sensors capture even a finest detail of your subject. Digital cameras use an array of sensors containing millions of tiny pixels which constitute to your final image. Each pixel contains a bucket like structure called “photosites”. When you press the shutter release button the light rays coming from camera’s lens is poured in to these photosites and once your camera completes the exposure, these photosites are sealed. These photosites are then internally processed to apply true colors using filters.

Although understanding these sensors is a big chapter and might occupy two three posts of mine but I tried my best to brief out in a layman’s terms.//

A camera that has large sensor will try to grab more of these light particles and thus fill in more of those photosites resulting in attaining a great detail of the subject. Following are some common sensor sizes available:

Sensor Type	Width (mm)	Height (mm)	Aspect Ratio
1/3.6″	4.000	3.000	4:03
1/2.3″	6.160	4.620	4:03
1/2″	6.400	4.800	4:03
1/1.8″	7.176	5.319	4:03
2/3″	8.800	6.600	4:03
1″	12.800	9.600	4:03
4/3″	18.000	13.500	4:03
1.8″	23.700	15.700	3:02
35 mm (film)	36.000	24.000	3:02

//
Sensor size Examples:

Camera	Model	Width (mm)	Height (mm)	Aspect Ratio
Nikon	D90, D80	23.700	15.700	3:02
Canon	EOS 450D / Digital Rebel Xsi	22.200	14.800	3:02

1.1. Burst Or Continuous Shooting Mode- As the name suggests, this feature[...]

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Choosing a DSLR (Part-I)

What DSLR should I buy? Is there an effective way to choose between different available DSLRs? Which one is the best DSLR in market these days? these are very common questions that I often get from my friends and readers, I thought why not scripting it for all my dear ones- It’s a good idea I guess

If you are in one of your initial phases of research and you still have doubts whether or not to upgrade your gears to DSLR then I would like to recommend you to read my post “Is it worth upgrading to DSLR?” Believe me you will not lose anything by reading it.

OK, now that you have made up your mind to buy a DSLR; let me take you through a range of steps that I usually recommend to make decision in choosing a good DSLR.

According to me a good DSLR is not the one which is expensive or has all the advanced features or has a live view or light weight but it is a camera that serves you with what you expect after paying thousands of dollars.

Just grab a pen and a paper and write down your own conclusions as against the 5 steps that I am presenting below:

1. What type of photography are you going to do?

2. Getting familiar with important features.

3. What’s your budget?

4. Compare and shortlist.

5. Step out to analyze.

Walla!! You are done. That sounds easy right??

Now let me dig into each of the steps which will make your life easier.

1. What type of photography are you going to do?

In brief, photography can be distinguished in a number of categories:

1.1. Indoor Photography

When you are planning to do a lot of indoor photography like shooting events mostly arranged indoors. Under this category you will mostly be shooting photos inside your premises, wedding halls, party halls, etc.

- You will be using external flash units a lot.

- You might have to shoot in no flash zones for which you will have to switch to high ISO settings.

- Due to dark conditions you will have to switch to lower shutter speed thus making an impact on the image quality due to hand shake i.e. Image stabilization.

- For image stabilization you will also have to have a tripod.

1.2. Night Photography

This is almost close to an indoor photography category and you will be mostly shooting stars, moon, city lights, fireworks, etc. under dark conditions.

- Again you will be using[...]

Is it worth upgrading to DSLR? (Part-II)

In my previous post “Is it worth upgrading to DSLR? (Part-I)” I wrote about understanding the characteristics, anatomy, Pros and Cons of point-n-shoot camera. In this concluding part I would like to brief out characteristics, anatomy, Pros and Cons of a DSLR. This will help you make a decision to whether or not to upgrade your gear to DSLR.

DSLR Characteristics

DSLR stands for Digital Single Lens Reflex. These cameras can be mounted with a variety of lenses like fish eye, wide angle, telephoto, etc. Such a variety of interchangeable lenses provides you with a greater creative control over ability to select lenses based on virtually any photographic situation.

The other major design difference between DSLR and point-and-shoot cameras is that most DSLRs only provide a “through-the-lens” optical viewfinder, although some models such as select Sony α (alpha) DSLRs feature the ability to compose and see a live preview of your shots on the camera’s LCD monitor. For DSLRs that don’t include this feature, you frame the shot by holding the viewfinder up to your eye.

Point-n-Shoot Anatomy

1. Light rays pass through the lens and strike a mirror.
2. The mirror reflects the light up to a focusing screen
3. Light rays then enter a block of glass called a pentaprism where they are reflected to produce an image which can be seen in the viewfinder.
4. When you press the shutter release button, the mirror flips up and shutter opens up which exposes the image to image sensor.

DSLR Pros

• Image Quality- These cameras[...]

Is it worth upgrading to DSLR? (Part-I)

With the advancement of technology and slashing prices of DSLRs these days many of you guys ask or at least have this question before upgrading from Point-n-Shoot camera to a DSLR. I get a lot of such queries from my friends and relatives, in fact I had this same question when I upgraded my gears to DSLR.

In this post I’ll try to cover all the aspects of ones needs to upgrade from Point-n-Shoot Camera to DSLR. I’ll compare the two and leave upon you to make the final decision. I’ll also provide links to various websites where you can gather more resources for your research.

In the first part I would like to brief out the strengths and weaknesses of a Point-n-Shoot Cameras and in the similar manner I’ll write about the DSLRs in concluding part.

Point-n-Shoot Characteristics

Point-and-shoot digital camera is defined by its in built lens which never separates from its body. The LCD (Liquid Crystal Display) always gets a continuous electronic version of the image. The image that the photographer sees through the viewfinder of a point-n-shoot camera is not the same image that passes through the primary lens of the camera. Rather, the image in the viewfinder passes through a separate lens. These cameras have focus-free lenses, with fixed apertures. These cameras also have a mode dial which enables you to easily select preprogrammed settings based on the scene (indoor, outdoor, day, night, portrait, landscape, macro, sports, etc.) without knowing the technical photography terms.

Point-n-Shoot Anatomy

1. Light passes through the lens and strikes a micro processing chip called Optics board which drives the lens motors for auto focusing and zooming.
2. Then it passes through another micro processing chip called Signal processing board which carries out the analog to digital conversion, auto focus, contrast, and data compression.
3. The final processed image is then passed over to the image sensor.
4. Image sensor passes it to the LCD.

Viewfinder sees altogether different image from a separate fixed lens.

Point-n-Shoot Pros

[...]

Understanding Shooting Modes (Part-IV)

In Understanding Shooting Modes (Part-I, II and III) I explained some of the auto and advanced modes. I’ll explain other available modes like Portrait, Landscape, Sports, Macro, and Night in this part.

Other Modes

In today’s cameras many other modes exist which I will be briefing out below. Availability and indication of these modes depends upon brand to brand. These modes are basically preprogrammed modes provided by your camera manufacturer.

 Portrait Mode

This mode is mostly represented by a head-and-shoulders icon. It creates a shallow depth-of-field thus throws out the distracting background. Turn the dial to use this mode and your camera will take care of everything else.

 Landscape Mode

This mode is mostly represented by a mountain icon. It produces a maximum depth-of-field allowing lens to capture everything….

Understanding Shooting Modes (Part-III)

In Understanding Shooting Modes (Part-I and Part-II) I explained Auto, Programmed and Aperture Priority Mode, I’ll explain and illustrate one of the other advanced modes called Shutter Priority Mode in this part.

Shutter Priority Mode

This mode lets you choose the shutter speed and the camera chooses the appropriate aperture (lens opening) for proper exposure.

Why to use Shutter Priority Mode?

Shutter priority will allow you to control how you capture your subject in motion. This mode is used when you want to increase or decrease the amount of blurring in the picture, the blurring is due to the motion of either the subject or the camera shake.

Try It

Visit some waterfall and experiment the following:

Slow Shutter Speed

1. Mount the camera on a stable tripod.
2. Turn your camera’s exposure mode dial to Shutter Priority.
3. Lower down the shutter speed to 1 Sec (or any thing above 1 Sec).
4. Focus the waterfall and press shutter release button.

Result Cameras shutter will allow light to fall on the sensor for….

Understanding Shooting Modes (Part-II)

In continuation to Understanding Shooting Modes (Part-I) where I described the Auto and Programmed Modes, I’ll explain and illustrate one of the advanced modes called Aperture Priority Mode in this part.

Aperture Priority Mode

This mode lets you choose the aperture (lens opening) and the camera chooses the appropriate shutter speed for proper exposure.

Just like human’s eyes, lens of a camera has an opening called iris that opens and closes according to automatic or manual settings. This in optical terms also referred as “Aperture”. Changing the aperture settings changes the size of the opening which controls the amount of light the lens passes through to the image sensor.

Why to use Aperture Priority Mode?

This mode is used when you want to have control over depth-of-field. This is measured in f-stops i.e. f/1.4, f/1.8, etc. Higher f-stop numbers indicate smaller aperture and vice-versa.

The “f-number” is the ratio of distance from the sensor/ film to the optical center of the lens in your camera. When you buy a lens for your camera, it will have a number on it, something like 18mm, 55mm, 105mm, etc. These numbers are called as focal length.

To put all of this simple, when the aperture of a 200mm lens (focal length) is 50 mm (aperture opening) wide, your f-stop will be f/4, because the ratio of 200/50 equals four. If you “stop down” your aperture to half that size – 25 mm wide – your f-stop will be f/8. (200 divided by 25.) So the “f-number” gets larger as you let in less light.

Understanding Shooting Modes (Part-I)

Today’s advance digital cameras basically perform automatically many of the tasks necessary for capturing a photo. The Auto mode or the Programmed mode is always a good option for beginners to shoot any scene. However, these modes don’t always produce up to the mark results. If you really want to utilize the power of your DSLR, you must learn and practice all the available modes.

Before discussing any of the available modes, we should understand exposure. Exposure is basically amount of light allowed to fall on photographic film (in case of a film SLR) or on image sensor (in case of a DSLR). The amount of light in a camera is controlled by setting the combination of Aperture and Shutter.

Auto (Point-and-Shoot) Mode

In Auto mode, it’s the camera that makes decision on what amount of light is allowed to fall on the sensor. Today’s digital cameras are intelligent enough to run their own algorithms to attain a best calculated aperture and shutter speed combination based on the projected scene. You don’t have to do anything more than to press the shutter release button. This method is also referred to as the “Point-and-shoot mode”.