DSLR stands for “Digital Single Lens Reflex”. In simple language, a DSLR is a digital camera that uses a mirror mechanism to either reflect light from a camera lens to an optical viewfinder (which is an eyepiece on the back of the camera that one looks through to see what they are taking a picture of) or let light fully pass onto the image sensor (which captures the image) by moving the mirror out of the way. Although single lens reflex cameras have been available in various shapes and forms since the 19th century with film as the recording medium, the first commercial digital SLR with an image sensor appeared in 1991. Compared to point-and-shoot and phone cameras, DSLR cameras typically use interchangeable lenses.
1) What DSLR Cameras Consist Of
Take a look at the following image of an SLR cross section (image courtesy of Wikipedia):
2) How DSLR Cameras Work
When you look through a DSLR viewfinder / eyepiece on the back of the camera, whatever you see is passed through the lens attached to the camera, which means that you could be looking at exactly what you are going to capture. Light from the scene you are attempting to capture passes through the lens into a reflex mirror (#2) that sits at a 45 degree angle inside the camera chamber, which then forwards the light vertically to an optical element called a “pentaprism” (#7). The pentaprism then converts the vertical light to horizontal by redirecting the light through two separate mirrors, right into the viewfinder (#8).
When you take a picture, the reflex mirror (#2) swings upwards, blocking the vertical pathway and letting the light directly through. Then, the shutter (#3) opens up and the light reaches the image sensor (#4). The shutter (#3) remains open for as long as needed for the image sensor (#4) to record the image, then the shutter (#3) closes and the reflex mirror (#2) drops back to the 45 degree angle to continue redirecting the light into the viewfinder.
Obviously, the process doesn’t stop there. Next, a lot of complicated image processing happens on the camera. The camera processor takes the information from the image sensor, converts it into an appropriate format, then writes it into a memory card. The whole process takes very little time and some professional DSLRs can do this 11+ times in one second!
The above is a very simple way to explain how DSLR cameras work.
To read a lot more about DSLRs, check out this great article at Wikipedia.
My name jeff
Hi sir,
I am following your site since a week and I am loving it. Sir I wanted to buy Canon 80d with lens 18-135mm so can please brief me how it would or can I get any recommendation from you.
Thank you!
Thanks for the simplified article, for news users like me
A very informative but more technical article. Does mirror-less camera function the same way? Is there any article based on mirror-less cameras? I would love to read it.
I also wrote about, how DSLR camera focuses and tried to explain it in more simplest way!
Please go through it and leave your feedback..
siddharthmalkania.com/how-d…a-focuses/
Regards,
Siddharth Malkania
This content has helped me so much for my finals. Thank you! :)
I am somewhat leaning towards photography, it fascinates me, any words of advice on what or who should i pursue?
I don’t have any point of reference, if you would be so kind to shed some light it would be very kind of you.
Hi Nasim
I typed” want to know about DSLR” :) in google and read a bit about it and now here in your blog. I had no clue of DSLR’s attractions. My boy friend has been talking about it and I want to surprise him by getting one. From reading all the above posts from many and your responses I picked the below for my Boy friend.
Nikon D90 12.3MP Digital SLR Camera (Black) with AF-S 18-105mm VR Lens and AF-S NIKKOR 50mm f/1.8G Twin Lens 4GB Card + 70-300mm VR Lens.
Could you please advise if I made the right choice and would he be happy with this choice? I don’t want him to be upset that I spent so much but ended up picking something that he did not like so much :) Your advice will be of great help. Thank you.
Hi Sir
i am a middile range photograper i am using still my canon D600 now thinking to upgrade my camera therefore kindly help me to find out a good camera. there is two cameras in my mind 1Canon 80D or Nikon D7200 which camera you can suggest me or more
waiting for your valuable comment
Dear Nasim,
I’m beginner & I have completed my Basic Course of Photography. Now I’m moving ahead for Advance Course & Diploma.
Obviously Now I have to buy the DSLR. My Teacher has suggested me to buy Canon 700D 18-135mm camera, but when I have done model to model comparison, I have found Nikon 5300D has better features/Specification compare to 700D & price wise slightly cheaper.
Can you help me, which model I shd buy 700D or 5300D? I heard that Nikon lenes are not easily available if we want to upgrade later on.
Hi
i am a biggner of the photography
I just want to know the difference between the camera body and camera lens i.e what are all specific settings/configuration are associated to camera body and what are all specific settings/configuration are associated to camera lens.
like aperture, ISO, shutter speed.
the reason for this question is people buy camera body separately and camera lens separately, so in that case i just want to know when i say camera body what are settings will be associated to camera body and what are all settings for camera lens.
can you please help me to understand this.
Thanks
Sathish
Hi Nasim,
Accidentally I have found this website and this is very interesting site, more information for a beginner. I have some questions regarding DSLR cameras.
1. First I planned to buy Nikon D5200 with 18- 55 mm lens, but later I bought Canon 1200D with 18-55mm + 55-250mm lens, is this deal good for me or not?
2. Canon 1200 D is the beginner camera for DSLR, if I want to upgrade my photography, then should I need to upgrade my camera as well as lens or only only lens I can upgrade? or only camera upgrade is enough?
Thanks Nasim , for very good and informative article .