Basic question about focal length

[helmar_fernandes]

<p>Hi. I'm a Brazilian enthusiast of photography. Forgive my terrible English.<br>

I have a Nikon D5100 and there's something that may be very simple for you, but I still can't understand.<br>

I've bought a 55-200mm lens thinking that with this lens I would be able to reach distant objects, since I've read that what really matters is not the zoom but the focal length in a lens.<br>

So this is my question: I use to take pictures with a zoom camera (Canon SX110is) which is a 10x zoom with a focal range from 6 to 60mm. Since what really matters is the focal length not the zoom how can a 60mm lens can go further than a 200mm lens? Knowing that my crop factor in D5100 is 1.5x it means that I'm really taking pictures in 300mm. But this lens doesn't reach the half of the distance the Canon 6-60mm can reach.<br>

To get the same distance what kind of lens I'll have to buy? I'm a fisherman and I use to take pictures of birds in trees with my old 10x optical zoom lens. What do I do now? Take the Nikon and put it in a box and continue using my old camera? Or do I have to buy a 600mm lens to take the same pictures I use to take before?<br>

I know this is a very basic question for you, but this is confusing me.</p>

<p>I'll appreciate any advice.<br>

Thanks!</p>

<p>Helmar</p>

[JDMvW]

<p>What matters is the combination of the "crop" (the actual sensor size) and the focal length.<br>

I think, but am not sure, that on your Canon the ratio is such that your 60mm is roughly the <strong><em>equivalent </em></strong>of a 333mm lens on an old 35mm film camera.<br>

So, yes, the 200mm lens on the Nikon is shorter <em>in effect</em>, but there shouldn't be a lot of difference. To see significantly more 'reach' you probably need to go to one of the 70-300mm or so lenses.</p>

[jcuknz]

<p>A fun question for sure :-) <br>

The apparent reach of a lens depends less on its focal length than the size of the sensor it has behind it. The Nikon has an APS-C sensor of 23.6mm across while the Canon is 6.17mm across. Imagine the Angle of View or 'reach' one would get if you cropped the Nikon image to 6.17mm, or put another way cropped so you just used the centre 6.17mm instead of the full 23.6mm. The maths are beyond me but I guess in effect you have organised the Angle of View of a 500mm lens on the Nikon. In practice when comparing the cameras I guess you could crop the Nikon that much and still retain whatever image quality you have with the Canon but I have not done that and made the comparison so it is a guess on my part.</p>

<p>You need to get your mind around the concept of "Angle of View" which is the balance of the focal length and the size of the sensor. If you look at the Canon I think you will probably see markings on it indicating it has an AoV ranging between 36mm and 360mm compared with the 55 to 200 [ 82.5 to 300 with the crop factor] of the Nikon.</p>

<p>Angle of View is usually for simplicity [of those who have grasped the concept and confusion of those that have not] expressed in equivalents of the focal length of a lens used on a full frame digital or 35mm film camera. ie. with a sensor 36x24mm as opposed to the 23.6mm of your Nikon and 6.17mm of the Canon</p>

[martin_z.]

<p>Helmar, your English is far better than that of many Americans who post online.</p>

[john_wheeler6]

<p>Hi Helmar - I suspect you have two issues going on. Also, which camera is better for you depends on your needs and what meets your needs.<br>

<br />From an angle of view perspective only, your angle of view of you 55-200mm lens on a D5100 would require a 82-300mm lens on a 35 mm camera. (1.5X factor)<br>

<br />The angle of view of the 6-60mm lens on your SX110is would require a 35-350mm lens on a 35mm camera (5.8X factor) or a 23-233mm lens on your Nikon D5100 <br>

<br />Since you observe that you are over 2X off in total reach, I suspect that you are not just using the 10X optical zoom on your SX110is yet also some of the additional 4X digital zoom that this camera provides. <br>

That 4X digital zoom just records a smaller portion of the pixels in the center of the sensor. Effectively you taking a picture with digital zoom with a much smaller number of MPixels and reduced quality. This is all done in camera. You can do the same with the D5100 by cropping in post processing with a photo editor.<br>

So it depends on what you want and how much you want to invest. The larger sensor cameras inherently can provide a lower noise image (gathers more light) yet you run into the issue you have discovered. If you want to extend the reach of the Nikon without paying for a much larger focal length lens you could consider a Nikon TeleConverter (can add up to 2X reach). Depends on your needs, your desires to post process, and dollars to invest. Hope this helps.</p>

[helmar_fernandes]

<p>Thanks guys for your replies.<br>

JDM von Weinberg I confess I have exaggerated when I said my 200mm didn't reach the half of distance... I think your're right. A 70-300mm will give me the same reach I use to have. <br>

JC Uknz. I didn't understood when you said the Canon sensor is 6.17mm across. I'll research about it because it made me more confused.<br>

<br />Hey Martin. Thanks for encouraging me to put my English in test. I never had an English class.</p>

[helmar_fernandes]

<p>Hi John Wheeler.</p>

<p>I never used the digital zoom in my old camera. I keep it disabled. But as I said in my first reply I confess that I exaggerated when I said I couldn't reach the half of distance. I was thinking about a friend´s zoom camera that is a 18x optical zoom. Sorry.<br>

Comparing both my cameras the difference isn't too much as I said.<br>

Does the TeleConverter decrease the image quality?</p>

<p>Thanks</p>

[JamesFarabaugh]

<p>helmar,<br>

JC is explaining that the size of the sensor in your SX110is measures 6.17mm wide by 4.55mm tall. And sensor size is what crop factor is all about. A traditional 35mm camera would have a sensor measuring 36mm x 24mm, which is the baseline for sensor measuring (1.0x crop factor). Your D5100 has a 23.6mm x 15.7mm (1.5x crop factor), and as mentioned your SX110is, at 6.17mm x 4.55mm, has a 5.8x crop factor. The <em>effective</em> focal length is equal to the actual focal length multiplied by the camera's crop factor. For example, suppose you have a 100mm lens. The effective focal length if you attach that 100mm lens to a full frame 35mm camera is 100mm (100 x 1 = 100). The effective focal length if you attach that 100mm lens to your D5100 is 150mm (100 x 1.5 = 150). If you could attach that lens to your SX110is it would have an effective focal length of 580mm (100mm x 5.8 = 580).</p>

<p>Now, before you start thinking that smaller sensors are better because you get much more effective zoom with a small lens, there are major disadvantages to small sensors. Those include generally fewer pixels (though this is rarely a detriment, unless you print enlargements), excess image noise, poor low-light performance (related to image noise), and less control over depth of field.</p>

[john_wheeler6]

<p>Hi Helmar - That is a good question about the impact on quality of the image using a teleconveter. A simplified answer would be yes, using a 2X teleconverter on a 200mm lens in general would not be as good in quality as a 400mm Nikon lens with similar Aperture. However, here are some more details on choices to have a larger reach / smaller angle of view<br>

<br />1) Just crop your image down with the 200mm f4 lens. You use the same exposure settings (ISO, shutter speed, aperture/depth of field) yet the number of pixels used is smaller and the image is degraded through the crop to some degree - This may not matter if you are just sharing images on the web and you don't need as many pixels yet does make a difference if you are blowing up your image<br>

2) Use a teleconverter with no post processing cropping. In this case, a smaller portion of the image from the lens is magnified over the entire sensor. All sensor pixels are used yet there is less light and you either have to decrease shutter speed, increase aperture setting (which changes depth of field) or increase ISO setting which increases noise. So while the teleconverter somewhat changes the quality of the overall lens system, you could have issues/degradation due to required changes to your exposure settings. If you are on a tripod with still subjects you could just reduce the shutter speed and have only minor degradation of image due to the teleconverter characteristics<br>

3) Best quality would be to use a native 400mm f4 lens. Unfortunately those can be quite expensive compared to a teleconverter. <br>

So you have choices. My personal approach is to get the basic set of lenses that I want to have to cover the most common range of angles of views that I need and crop images to get the angle of view I need. Understanding the limitations of teleconverters if they are still of interest I would get one to extend the base capabilities of my lenses. If my primary business needed the highest resolution images (e.g. significant enlargements) and needing a telephoto lens vs just moving closer to the subject I would then bite the bullet and invest in a more expensive longer focal legnth lens. Of course this is just me. Hope the extra info is useful.</p>

[bebu_lamar]

<blockquote>

<p>Those include generally fewer pixels (though this is rarely a detriment, unless you print enlargements), excess image noise, poor low-light performance (related to image noise), and less control over depth of field.</p>

</blockquote>

<p>I actually enjoy the fact that the tiny sensor gives me lots of depth of field so I consider that as an advantage. Of course, low pixel count, high noise etc.. are disadvantages. </p>

[JamesFarabaugh]

Bebu, larger sensors are capable of a much larger range of DOF, from very shallow to infinitely deep. On the other hand smaller sensors only have deep DOF with no option for shallow when it is warranted. For that reason a larger sensor still holds the advantage, though in your case that advantage has little value to you (which is fine).

[frank_skomial]

<p>Nikon 1 (N1, N2, V1, V2) cameras have small sensor of 2.7x crop factor, with reasonable performance on AF-S Nikkor lenses, giving impression of pictures taken with much longer lenses. However, at current technology, sensors in crop factor range 5x or larger loose a lot of picture quality properties and perfect lighting is needed as well as shooting techique. Possibly with further advances in sensor development, such small sensor camera could compete with larger cameras.<br /> With such a camera and a reasonably long Nikkor lens, you would not need a true 400/4 lens.</p>

<p>If you had such a huge 400/4 lens, perhaps you would need a donky or a mule to carry it for your.</p>

<p>Recent pixel density of the D800 sensor gives a lot of in-camera file image magnification, negating somewhat the advantage of larger crop factor cameras.</p>

<p>E.g. when most used cameras were D700 (FX crop 1.0) , and D300 (DX crop 1.5), both with 12 MP images, the use of DX native camera gave advantage of greater pixel sensor in image file magnification by about 1.5 times for distant photos in wild life areas. Where image in file size is measured in pixels and not necessarily in less practical sizes as in mm.<br /> However, 36 MP camera DX crop factor mode gives already 15 MP worth of pixels, that is more than the D300's 12 MP in camera detail value of native DX camera. Thus I would prefer D800 over D300 for wildlife pictures, since there is no crop factor advantage from native crop camera in this comparison.</p>

<p>This example tells you that one should not generalized advantages of any crop factor camera for wild life, but lpok at if a camera and lens is suitable for the task, from image quality and optical reach perspective.</p>

<p> </p>

[Wouter Willemse]

<p>Helmar, John,<br>

Please take care with (recommending) teleconverters. They're not a cheap easy solution. And John is missing some vital points on TCs. Apart from decreasing image quality, teleconverters also affect the aperture of a lens. With a 2x TC you loose 2 full stops, making a f/4 lens into an effective f/8 lens. This has some serious side effects:</p>

<ul>

<li>You need a lot of light for a f/8 lens;</li>

<li>Nikon only garantues proper AF functioning with lenses up to f/5.6. With a f/8 lens, AF will be either erratic, or not work at all;</li>

<li>Manual focus will also be harder, as the viewfinder also gets dimmer with a f/8 lens.</li>

</ul>

<p>So, on a theoretical 200 f/4 lens with a 2x TC, you have a nearly unusable 400 f/8 lens. Now note that the 55-200 is NOT a f/4 lens, but f/4-5.6, meaning it is f/5.6 at the 200mm end. Add a 2x TC, and you have a 400mm f/11 lens. That's really not going to work well.<br>

On top of that, the decrease of image quality with 2x TCs are very considerable and very noticable.</p>

<p>Next to that, specific for the Nikon TC's, they are designed to work with a limited range of lenses. Nikon has reasons for it: on many lenses, the rear element is far to the back, and would bump into the front element of the TC. The second reason is the "abilty" of a lens to deal with the loss in quality, and the loss in aperture. The cheapest lens on which their TCs work officially is the AF-S 300mm f/4 - around $1500; and it only works really well with the 1,4x TC. The 2x TC works well with some lenses, none of them cheap (think the 70-200 f/2.8VRII, 300 f/2.8VRII ecc. - so, $2500 and up).<br>

The Nikon TCs can be modified to fit all lenses, but the risk of damaging the lens and the TC, plus the loss of quality and aperture stays there.</p>

<p>So, TCs are certainly not a cheap way to add length. They're a cheap way to add length to expensive, high quality lenses. The zoom Helmar has is a very decent consumer quality lens, but certainly not one that will work well with a TC. Going over 400mm with decent quality, it will simply cost you quite a lot of money.</p>

[helmar_fernandes]

<p>Ok guys. Thanks John, thanks Wouter... I really appreciate your help.<br>

Don't forget I'm a hobbyist not a pro.... I only want to take some pictures of my beautiful city, my daughter and my fishing trips. My wish for long distance photos is only because of the opportunity of getting some great pictures of birds and other animals in my fishing trips. <br>

So, that's what I decided: I wont back to my old camera. I think my 55-200 lens is good enough for me since now I know what I can do with it. Thanks to you. When I have some money I'll try to purchase a 300mm lens but there's no hurry for it. I think I can do some good pics with the stuff I have.</p>

<p>Thanks a lot guys! You have made things clear for me!</p>

[john_wheeler6]

<p>Good catch Wouter.<br>

Here is a link to the PDF file for compatibility of Nikon Lenses with their teleconverters that includes all compatibility issues including autofocus<br>

http://www.nikonusa.com/en_INC/IMG/Assets/Common-Assets/Images/Teleconverter-Compatibility/en_US_Comp_chart.html<br>

<br />Here is a more complete listing from a Nikon European site:<br>

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CDkQFjAB&url=http%3A%2F%2Fwww.nikonsupport.eu%2Feurope%2FManuals%2FDrdIaQvRZv%2FTC_converter_compatibility-EN_01.pdf&ei=wROdUPTMC5T7yAGzpIHABA&usg=AFQjCNFeIcUeBkeeFfrcWxxRD8iOf5i_Xg&cad=rja</p>

[jcuknz]

<p>There are telephoto <strong>converters</strong> which are the DSLR tool and fit between camera and lens and there are telephoto <strong>adaptors</strong> which are added to the front of the camera lens and are what the fixed lens camera uses ... P&S or bridge.<br>

While the converter increases the focal length of the lens it effectively makes the aperture smaller hence the x1.4 and x2 stop loss of light when you use them.<br>

On the other hand I have two tele adaptors, the Raynox 2020 and the Olympus TCON x1.7 and both loose me about a third of stop. Originally I bought both for my Panasonic FZ30 and the the FZ50 and with those cameras they work well.<br>

However when adding them to the x10 lens I use on my Panasonic M4/3 camera I find that I loose around 1.6 stops of light which I believe is due to the mismatch of camera lens to adaptor. To avoid light loss with adaptors, or any lens being added, it is important that firstly the camera lens has a narrow enough angle of view to see through the adaptor* and secondly that the adaptor is the same size or bigger at its rear end than the front of the camera lens.<br>

I base this on an experiment in adding my Raynox 2020 to my DSLR's Tokina f/4 90-230mm lens. The Tokina is a big lens and the Raynox is smaller. The result was a loss of around two stops just the same as if I had used a x2 converter. <br>

A further 'play' has me adding the TCON x1.7 on the front of the x10 zoom of my M4/3 camera. There is a mismatch with the result that it changes the f/5.8 of the camera lens to around f/10. There is a good side to this compared with the DSLR. The m4/3 camera uses contrast detection focusing which doesn't have the problem that the DSLR's phase detection has of not working as well when you close down the aperture. CD snaps into focus just the same with or without the adaptor and like a DSLR the M4/3 can afford to use a higher ISO to compensate for the small aperture.<br>

*if it doesn't then you get vignetting or 'black corners' to the photo.<br>

Sorry you didn't follow me earlier I guess you didn't appreciate just how small the sensors of P&S and bridge cameras are :-) It is amazing that they can cram 16Mp into such tiny things.</p>

[absent]

<p>Hi Helmar,<br>

Here's an exercise you may find interesting.</p>

<p>Take both your cameras and choose a subject (maybe a building or tree) that nearly fills the viewfinder when fully zoomed in. Use a tripod if you have one for consistency; if not, line up the center of the finder on a prominent feature of the subject. Take pictures with both cameras fully zoomed in. Try to use the same ISO setting and a lens aperture which will give the best quality (probably f/8 or so). A bright sunny day is best so you can use a high shutter speed. Very important: Make sure both cameras are set to their highest image size settings.</p>

<p>Open both images on your computer screen and re-size them so each fills half. The Canon image should show the subject "bigger", because of the longer focal length (360 vs 300 mm equivalent).</p>

<p>Now, re-size both images to 100%. I'm betting the Nikon's image will show more detail because of the higher resolution (16 vs 9 MP). The sensors are differently shaped (4:3 for the Canon vs 3:2 for the Nikon), but the ratio of the short sides (3456 pixels Nikon vs 2592 Canon) is 1.26, which is greater than the 1.2 ratio of the equivalent focal lengths.</p>

<p>Put another way, the Nikon's sensor is 4928 x 3264 pixels. You can take a 3456 x 2592 crop (the size of the Canon's sensor) from this and it should show a little more detail than you get from the Canon. Plus you don't have to frame your shot as precisely. In practice, you can print an 8 x 10 at 200 dpi using 1600 x 2000 pixels, so if you can fill half the Nikon's frame with your subject, you should be good to go.</p>

<p>The Nikon has many other advantages which will become apparent the more you use it, including much better high ISO performance and faster autofocus.</p>

<p>I went through a similar exercise last spring when I bought the d5100 and 55-200 after using a Panasonic FZ30 for several years. After making this comparison, I haven't used the Panasonic since. I did buy a 70-300mm VR lens for longer reach at airshows, and would recommend it when you have the funds available.</p>

[keith reeder]

<blockquote>

<p>On the other hand smaller sensors only have deep DOF with no option for shallow when it is warranted.</p>

</blockquote>

<p>That's nonsense, James - a completely unfounded sweeping statement.</p>

<p>For <em>tiny sensors with no option for a change of lens</em> it might be true, but otherwise...</p>

 

[Alan Marcus]

<p>Hi Helma,</p>

<p>As you know, the Canon SX110is features a zoom lens range 6mm thru 60mm. additionally, this camera has an electronic zoom 2.2X. Thus if the lens is set to max zoom with the 2.2x applied, the camera functions as if it were equipped with 60 x 2.2 = 132mm telephoto. The real question is how much magnification does this give?</p>

<p>Traditionally a lens delivers a "normal" view when the focal length used is about equal to the diagonal measure of film or chip. This camera sports a tiny sensor that is only 16.7% of the size of a full frame. This makes the magnification factor (crop factor) 1/0.167 = 6.</p>

<p>In other words, set at minimum zoom of 6mm, the view as seen by the SX110 is equivalent to a full frame operating with a 6 x 6 = 36mm wide-angle. Set to the maximum zoom of 60mm is the equivalent of 60 x 6 = 360mm. If the electronic zoom is at set to maximum, we multiply 360 x 2.2 = 792mm. In other words, set to maximum optical and electronic zoom the SX110 delivers the equivalent of 792mm mounted on a full frame 35mm.</p>

<p>As to magnification, traditionally 50mm is considered "normal" for the 35mm full frame; thus at 792mm the magnification obtained is 792 ÷ 50 = or about 16x. In other words, the SX110 at maximum brings birds 16 times closer; thus a bird 100 meters away appears as if it were only 100 ÷ 16 = about 6 1 meters away.</p>

<p>Now the D5100 sports a sensor that is smaller than a full frame. It is 66% of the size of a full frame; thus the magnification factor is 1/0.66 = 1.5.</p>

<p>To attain 16x magnification on a full frame you must mount 50 x 16 = 800mm lens. Since the D5100 sports a crop factor of 1.5, you must mount 800 ÷ 1.5 = 533mm lens to obtain the same magnification.</p>

<p>More gobbledygook from Alan Marcus</p>

[James G. Dainis]

<center><img src="http://jdainis.com/tree6.7.jpg"></center>

 

<P>The above represents the image circle thrown by a lens at 50mm focal length.<P>

 

The yellow rectangle shows how much of that circle would fall on a full frame sensor. This is what you would see in the viewfinder, LCD panel, and in a photo made with that camera.<P>

 

The red rectangle shows how much of that circle would fall on an APS-C sensor. This is what you would see in the viewfinder, LCD panel, and in a photo made with that camera.<P>

 

The blue rectangle shows how much of that circle would fall on your Canon sensor. This is what you would see in the viewfinder, LCD panel, and in a photo made with that camera.<P>

 

Taking a photo of a large bird in that tree with the Canon 6.17mm wide sensor (blue rectangle) would get you a frame filling shot of the bird. <P>

 

Taking a photo of a large bird in that tree with a full frame 36mm wide sensor (yellow rectangle) would get you a frame filling shot of the entire tree.

[dan_south]

The lens projects a circle of light onto the sensor (or film) like a flashlight shining on a wall. The focal length is the

distance of the projection (from light to walk, or from lens to sensor).

 

If the wall has a large rectangle drawn on it and a smaller rectangle inside of the large one, the large rectangle will receive

a larger portion of the circle. The small rectangle receives a cropped version of what the larger rectangle receives.

 

The sensor in a compact camera is like the small rectangle. A DSLR has a larger sensor, which is analogous to the

larger rectangle. The crop factor of the smaller rectangle can give the appearance of a long focal length. For the large

rectangle to receive the same amount of crop, the flashlight would have to move back some distance. This is analogous

to using a lens with a longer focal length.

 

Focal length combines with sensor size to create an effective croo factor.

[helmar_fernandes]

Thanks guys for all responses, now I know what I was looking for

[JamesFarabaugh]

<p>Keith, please explain. My understanding from what I've read about full-frame vs. crop sensors is that if you are shooting at the same aperture the shot taken with the larger sensor will have a shallower depth of field than the shot taken with the smaller sensor. According to you that is unfounded and false, so please explain it so that I understand. Thanks.</p>

[Alan Marcus]

<p>Depth of field is such a complex subject; most everything you say has “but-ifs”. First you need to know that the camera lens images by gathering and then projecting each point on the subject, reproducing it as a point of light on the surface of film or chip. If the lens is a good one and if the photographer focused sharply, the point of light playing on film or chip will be super tiny. Its actual size on the finished display must be 1/4mm (0.25mm) or smaller to cause an observer to declare the image acutely sharp. Now this is complicated by the fact that today’s cameras are tiny thus their images must be enlarged to make them viewable. As an example, the 35mm full frame camera is presumed to require 8x magnifications (make and 8x10). This dictates that size of the point on film or chip must be 0.03mm to enable it to withstand the needed enlargement.</p>

<p>What I am trying to tell you:<br>

A larger format camera gains depth of field because less magnification is required to obtain a given final image size. This is true because larger format can afford a larger permissible image points (circles of confusion). However larger formats require longer focal length lenses to obtain an identical angle of view to match its smaller format cousin. The effect of the longer focal length reduces depth of field and this is the stronger influence. Thus the larger format will have a shallower depth of field, all things being equal.</p>

<p>A compact digital with its smaller sensor requires 12x magnification to yield an 8x10. Thus the size of the image point must be super-duper tiny 0.02mm. However the compact digital dictates that a shorter lens be mounted (66%). The shorter focal length is the dominate influence. Thus the smaller format displays more depth of field then its larger course.</p>

<p>Factors of depth of field:<br>

f/number is higher (stopped down)<br>

focal length selected is shorter<br>

subject distance is increased<br>

circle of confusion size relaxed (more distant image viewing)</p>

<p>More gobbledygook from Alan Marcus</p>

[john_wheeler6]

<p>Here is a reference table that might help. This table of values is for images where:<br /> - The distance from camera to subject is that same in all cases to maintain the same image perspective (relative size of objects at different distances<br /> - The same angle of view so the subject fills the film/sensor the same amount<br /> - All images are enlarged and printed at 8x10 inches and viewed from a distance of 10 inches and the same sharpness criteria is used for those prints in each case.<br /> - In my case I use .225mm as the size of a circle on an 8x10 print that cannot be distinguished from a sharp dot on same print for the average viewer viewing said print at 10 inch distance. I use .225mm because that matches what DOF Master used in their online calculators.<br /> The table below gives for a wide variety of film/sensor formats (8x10 down to a 1/2.3 sensor) what focal length lens must be used and what aperture to achieve the same angle of view and DOF for each 8X10 print. It's a simple scaling based on the length of the diagonal of the film/sensor.<br /> So note that to given the above elements held constant as described, you get the same image (perspective, size of subject in print, and DOF) on an 8x10in camera with a 305mm lens at F64 as a 35mm camera with 41mm lens at F8.5 and the same as a 1/2.3 camera (e.g. SX110) with a 7mm lens and F1.5<br /> <br /><br />Enjoy and comments welcome<br /> BTW - you can verify this using the DOF online calculator<br /> <br>

<img src="http://i774.photobucket.com/albums/yy26/thebestcpu/Photodotnet/Screenshot2012-11-12at13905AM.png" alt="" /></p>