More digital noise with the electronic shutter?

<p>I asked at DPR why they have two sets of photo samples, one with the mechanical shutter and one with the electronic shutter. Someone pointed out that the electronic shutter produced more digital noise-I can't see it in the samples. For most of what I photograph I prefer the electronic for its silence. Beside, isn't the life of a camera always expressed in shutter cycles? XT10 should last forever if I never use the mechanical shutter!</p>

<p>The electronic shutter causes more electronic noise, has a "rolling shutter" effect on moving objects (e.g., turns helicopter blades into sickles), and produces 12 bit raw images v 14 bit. The situations which the silent shutter is needed don't suffer significantly from excessive noise because they usually require higher ISO and no flash too. You don't expect (or need) perfect results. The effect of electronic first shutter on noise is negligible, and is very useful when you want maximum sharpness on a tripod or no vibrations for astronomy. The rolling shutter effect occurs because a CMOS sensor is sampled row by row, rather than as a whole for CCDs.</p>

<p>If you are taking photos of people for portraits or at an event, leave the shutter noisy (e.g., electronic front shutter only). The silence is somewhat unnerving when people expect a sound indicating you've take a shot.</p>

<p>The life of a shutter is generally between 150,000 and 500,000 exposures. The replacement cost is about $400. For most people, the shutter will last until they find another camera they prefer, shelving the old one. For professionals, it is the cost of doing business - a LOT of business.</p>

<p>If you want the assurance that a full shutter affords, that's a viable option. Personally, I have never used the full shutter except to hear what the double click sounds like (not as bad for an A7Rii as for previous models, but still nasty).</p>

<p>If I understand the question, it is related to the way sensors are built.</p>

<p>For point and shoot, there is no mechanical shutter, the image sensor is always exposed to the image. Sensor cells are precharged, then a delay, the electronic equivalent of a shutter speed, and then the charge is moved somewhere else, to be shifted out and input to the A/D converter. </p>

<p>The "move somewhere else" step requires extra transistors, and possibly other complications, and makes the cell somewhat larger, relative to the image sensing part. That is, a relatively small part of the array is actually the light sensors, maybe about half.</p>

<p>With a mechanical shutter, less extra electronics is required in the cell, the area of the light sensing part is larger, and the electronic noise is reduced. The noise comes from a finite number of electrons making up the image at each pixel, and the statistical uncertainty in that number.<br>

There is additional noise in the amplifiers, again more significant as the signal gets smaller. </p>

<p>This is also the reason for an advantage in larger sensors, more than the increase in megapixels. Smartphones have many megapixels, but they are very small, and so noisier than the larger sensors in DSLRs.</p>

<p>Many cameras with electronic shutters have a system to make the sound of a mechanical shutter. Personally, I find that sound distracting.</p>

<p>If the digital shutter causes the sensor to be active more before the shot, it will heat up the sensor. The hotter the sensor, the more noise</p>

<p>Leaf shutters are quiet enough and fast enough. I dont like the idea of MILC because I like the mirror and dont like the focal plane shutter.</p>

<p>I've had adults ask if I could please turn off the shutter sound in my D3. All they've ever known was a smart phone or a digital P&S. I was working at a newspaper before most were a gleam in their father's eye, and shutters were not just a sound effect.</p>

<p>They have a point though, which is why I treasure the silent mode of a Sony A7Rii so highly. Looking back, it was rude of me to take so many shots when people were trying to hear a speaker or more significantly, music. I had the audacity to use an Hasselblad one time, for which I got verbally thrashed by the conductor.</p>