Shattered Sky: The case for a new camera

All this info is basic and reflects my current knowledge. I am largely self taught, but flickr has helped immensely. Feel free to point out flaws in what I say. I am by no means an authority on the subject.

 

I took this before I started to really appreciate what good equipment can achieve. The photo is of a spectacular sunset from my Lincoln Ridge Apartment. The clouds were scattered around the sky in a nice pattern and the light from the setting sun was still visible. I had to capture this picture...and this was the best my SD550 could do. How did I take it and a similar vertical shot?

 

I used the balcony as a tripod, used vivid colors (to boost the saturation bascially) and the slow synchro mode. Turning up the ISO on these camera typically results in lots of noise (and besides I barely knew what ISO was in August last year).

 

What is wrong with this picture you ask? Besides the exaggerated saturation, the picture only works in medium size. Try looking at the large or original sizes and the lack of detail becomes apparent. If you want to frame this, forget about it. It is not a good picture, but of course better than no picture...

 

What would I do today? First, I'd run and get my tripod. Tripods are a must for crisp low light shots, and it works especially well from the no-hassle environment of your balcony. The tripod provides absolute stability for the shot (assuming you don't kick it). That being said make sure to use remote release other the mere act of pressing the button may shake the camera. There are two options to avoid this: (1) use a timer or (2) buy a remote release device that plugs into the camera. Since your camera is firmly attached to the tripod and therefore stable, you can reduce the ISO to 100 and avoid noise/grainy issues (seeing pixels when you see the picture big basically).

 

Then I'd start playing in the Tv mode and have the camera automatically select an appropriate Aperture. However, the camera frequently selects inadequate aperatures so make a mental note of your Tv setting and move to Manual mode and use this as a starting point. I'd also experiment with cloudy WB and higher saturation. Finally, I'd play with my zoom to frame the picture differently. Not only did my SD550 have poor zoom range, but zoomed picture quickly get blurry without a tripod.

 

An advanced point and shoot can achieve all this. The only problem with the S3 IS is that it has limits on aperature, and these limitations make low light shoots hard in certain situations. For instance the S3 IS had a limit of f/8 aperature (the amount of light the camera allows into the lense). This is a problem if you want to shoot objects that are very dark or take traffic shots. It is also a problem with flare (since the lights get way to bright). But I'd probably be fine in this shot. So why bother getting a dSLR like my Rebel XTi?

 

First, the images are much higher quality even if you select the same setting. To see this try looking at one of my night images in original size shot with the S3 IS and the Rebel. Even shots that I consider high quality with the S3 IS do not even come close in detail. Why? The Rebel has a much bigger sensor and much higher quality lenses. This holds for all shots, but it most noticable in difficult light settings.

 

Second, what if I did not have my tripod? The remedy is then to increase the ISO, however, if you do this on a S3 IS the shot gets extremely grainy (i.e. pixelated). Sure, the S3 IS is a IS camera i.e. image stabilization, but in practice this does not buy you much. In contrast, the Rebel XTi does an excellent job of controlling noise at high ISO so I would simply go to ISO 800 or ISO1600 and try to stabilize against the wall of the balcony. You can also buy IS lenses for the Rebel (which sadly I don't have....to $$$ basically) or lenses with wider aperature (like my f/1.4 lense) - more on that later.

 

Why is an IS lense useful? Basically you can only handhold a shot at say 50 mm (how much you zoom) at a shutter speed of 1/50. In a low light shot you need to open the shutter long enough to allow enough light in so that your shot is not dark, but you are handholding and if you need to handhold for more than 1/50 you will get a blurry and useless shot (it is just impossible to hold the camera steady for that long). With a IS lense the lense adjusts for the movement and you may be able to get a crisp shot at a much slower shutter speed (which allows more light to enter). People say that you can improve 3-4 steps, that is from 1/50 to 1/20-1/15.

 

What does high ISO do? It increases the sensitivity of the camera to light and allows you to absorb more light all else constant. The benefit of this is that you can use a faster shutter speed and this increases the likelihood of getting a sharp shot. Examples tend to help so I will give one. Lets say I want to shoot the wall in my room. I put the camera in Av mode (to keep the aperture fixed) and it says 1/13 @ f/2.8 at ISO 100. This lense is 50mm fixed so using the rule of thumb I mentioned above, 1/13 will not result in a crisp shot (you can try using the continuous mode and snapping about 10 and keeping the crispest). An IS lense would help improve the shot, but my lense is (sadly not IS). So I increase the ISO to ISO 400 and down to 1/125 @ f/2.8. Now I can easily get a crisp shot. The downside is more noise; an easy way to notice this is do look at the sky in a night shot. However, with the Rebel graininess is negligible at ISO400.

 

What does a wider aperture do (lower f/stop)? It allows more light to enter and thereby reduces the time the shutter needs to be open (and increases the chance of getting a crisp shot). In example above I could reduce the f/stop further. For instance, at f/1.4 and ISO 100 I get a shutter speed of 1/50; the higher aperature (annoying aperature and f/stop go in different directions) allows me to avoid increasing the ISO.

 

The problem is that the basic lense on a Rebel XTi is cheap and is neither IS nor has a particulary low f/stop (3.5 with no zoom). It is easily overwhelmed in low-light shots. However, as you start decreasing the f/stop and move below f/2.2ish your DOF (depth of field - baiscally your lense will focus on some object and blur the background). So whereas my f/1.4 lense helps with low-light (especially indoor shots) to is key to pick the right place to focus (I now fondly refer to this lense as 'el lente loco' :))

 

So if you want to take high quality night shots or shots in low light get a dSLR like the Rebel XTi. You may be thinking, when do I really need these capability? Think about indoor shots. Often flash fails (and the flash on P&S's like my SD500 is poor in any event) and often it washes out the subtle natural light. Note! Flash would do nothing in the shot above (why? the range of the flash is very limited). Think about the time around dusk and dawn or if its overcast or what about shots inside a store. What if you zoom a lot especially in less than ideal light? There are so many shots I can now take with the Rebel that I could not even dream about with either the SD550 or the S3 IS (which is way better than the SD550) The only downside I see is price and the bulky size. You don't need to know much; just stick it in the auto mode (P is better) and start shooting and then learn by experimeting.

 

To make a long story longer: consider an example. I've always been a car freak and car photos - especially shot of moving cars - have always fascinated me. One experiment I had recently was taken shot of a moving car at night. This is hard given the low light and the motion of both cars. Increasing the ISO to 1600 (max for the Rebel) and reducing the f-stop to f/1.8 allowed me to get a decent shot at 1/60 (just right for a 50mm lense; I snapped about 4 as the Chysler 300C sped past and one was crisp). Given the high aperture it was also important to manual select the focus point and point it at the car.

 

There was one problem (and I had figured this out by testing on other cars). The shot was too dark. One solution was to increase the exposure to +1. This increases the demands for light and all else constant reduces the shutter speed (and the chance of getting a crisp shot). Check out the graininess of the shot. The is pretty crisp and sharp, but you can see the noise even in the large size. Try this shot with a point and shoot once....it is illustrative and you will not get close. Even the lense that came would the Rebel would be out of luck.

Done