Bivek Khatiwada, sept 1 Gone are the days when we had to rely on film-equipped cameras to capture our moments. With the advancements of technology, everything is getting digitalized. And that digitalization has encroached even the camera sector. In the past couple of decades, there have been substantial innovations on the camera technology. So these days, we do not require a film-equipped bulky camera to capture the professional shots. A small and portable camera does that sophisticatedly. And in that run, DSLR (Digital Single Lens Reflex) and mirrorless cameras are quite gaining momentum these days. Because of their portability and the flexibility in the operation, they are often preferred by many. However, users always find hard to decide one among the two while buying a new camera. So here, we will tell you all the differences between these two and help you decide the best fit for your needs.
Mirror
The major difference is the presence of mirror setup in the camera. In DSLRs, when the light enters the lens, it hits the mirror and is reflected through the pentaprism to the viewfinder through which we can see the image. Since there is an optical setup involved in the viewfinder, it is also known as the optical viewfinder (OVF). And when we take a picture through the DSLR, the mirror flips up allowing the light to hit the sensor directly. That is how a DSLR takes images. However, in the case of a mirrorless camera, as the name implies, there is no mirror and pentaprism setup. So the light hits the sensor directly and is transmitted electronically to the viewfinder. That’s why it is called an electronic viewfinder (EVF).
The viewfinder is one of the key components in a camera because it lets users look directly at the subject and composition while capturing the images. The viewfinder also shows an image of the subject, which will be recorded in the sensor when the photographer hits the shutter button. Although the optical viewfinders are considered better for their true colors, modern-day mirrorless also does a similar job. However, the mirrorless camera uses OLED panels on the viewfinder. And such panels consumes battery on the use.
Delay
In the mirrorless cameras, since there is the presence of EVF, in which the light is transmitted electronically, there might be some delay in the transmitting mechanism. And problems may arise while taking a shot if the subject is in motion. But there is also an advantage of the EVF as it shows the exposure level and intensity of light in the resulting images when the shutter button is pressed at the same instant. However, there are no such issues related to viewfinder lags in DSLRs as the OVF shows the subject status in real-time. But unlike the mirrorless camera, it is hard to predict the light intensity and exposure level with the OVF in the resulting images.
Size and Weight
Due to the absence of the mirror and pentaprism setup, mirrorless cameras are smaller and more compact than their DSLR counterparts. At the same time, mirrorless cameras also happen to be lighter. So these kinds of cameras offer better portability while carrying it around. 
Because of their size and weight, mirrorless cameras can easily be used in the gimbals and stabilizers with low payloads. And that’s quite an advantage.
Lenses
DSLRs have already possessed a well-established stature in the photography/videography industry, so there are numerous options in the lenses. However, the mirrorless technology being new in the industry lacks the variety in lenses. So while buying a new camera, the availability of lenses depending upon the needs and requirements should also be considered.
Battery life
Due to the smaller size, usually smaller batteries are provided into mirrorless cameras. And unlike the OVF, the EVF also devours a considerable battery juice. So the battery backup is pretty minimal in the mirrorless cameras. However, in DSLRs, utilizing the spaces inside its bigger body, bigger batteries are provided to it, which lasts usually longer than mirrorless cameras.
Autofocus
Traditionally, the DSLRs have been faster while autofocusing but since the launch of Sony α9 and α6500, we have seen mirrorless cameras catching up fast. So the autofocus of both cameras is comparable these days in the case of normal shots. But DSLRs have a slight edge over the mirrorless cameras while autofocusing on a low light scenario. The mirrorless cameras, however, outshines the DSLRs when it comes to autofocus while shooting videos. Users tend to get better autofocus tracking in mirrorless, so, the videos tend to look better because of the better autofocus.
Silence
Because of the presence of movable parts like a mirror in the DSLRs, it is noisier while capturing images even when kept in the silent mode. However, due to the lack of movable parts, mirrorless cameras are usually silent. So if you wish to capture images without producing any sound, say wildlife photography for an instance, mirrorless cameras come in handy.
Image Stabilization
DSLRs are not usually provided with the image stabilization mechanism. Only the lenses of the DSLR possess the stabilization mechanism. Whereas, usually all the mirrorless cameras and their lenses are provided with a stabilization mechanism. And it can be pretty useful while taking stable shots even without a tripod or any sorts of stands.
Connectivity
Unlike the many DSLRs, mirrorless cameras are provided with Wi-Fi and NFC options, because of which, it is easier to transfer the captured photos and videos without any sorts of interfacing devices.
With their bigger batteries and wide variety of lenses, the scope of DSLRs looks quite impressive. But as the same time, the mirrorless cameras are evolving and the camera makers are focusing greatly to bring more lenses to increase the flexibility and bigger batteries to improve the battery life. So you cannot go wrong with the mirrorless cameras. Considering all the aforementioned aspects, you can decide the one, which best suits your needs and requirements.