Which is better: SLTs or DSLRs?

Digital Single lens Reflex camera advantages and disadvantages




so for anyone who hasnt been following this, DSLR of course standards for Digital Single Lens Reflex, as in camera.

The DSLR is, of course, a digital version of the Single Lens Reflex camera, which has been the most popular professional camera format since the 1960s.

,,The idea behind the SLR is that the very same lens used for shooting the photograph is used for composing the photo.

The camera includes a reflex mirror in the image path, which directs light to a focusing screen when used as a viewfinder, and swings out of the way to allow a photo to be taken.

In modern SLRs, a prism or system of mirrors is used to deliver an eye-level viewfinder.

,In the DSLR, the main change to this design is the use of a digital image sensor rather than film.

The mirror, the focal plane shutter (a shutter that sits right in front of the imaging medium), the prism, etc.

are the same.

Naturally, fully mechanical SLRs existed, but gave way to electronic SLRs in the film days, and continued into todays all-electronic DSLRs.

,In 1965, Canon came up with a variation of the SLR, which they dubbed the Pellix.

The camera used a pellicle mirror, also known as a beam splitter.

The mirror is semi-transparent and never moves.



it directed some light to the viewfinder and some to the film.

Subsequent pellicle-mirror cameras included the Canon F1 High Speed, the Nikon FH2, the Canon EOS Rt (my first Canon SLR) , and the Canon EOS 1N RS.

,The advantage of the pellicle mirror in all of these cameras is speed.

The fixed mirror results in a much simpler system, the camera just fires the shutter to take a shot, no need to move the mirror, no blackout in the viewfinder.

The disadvantage is that the film and viewfinder only get part of the light, so you have a relatively dim viewfinder and you lose 1/3 stop or so (depending on camera design) on your film exposure.

And it theres any scratch, dirt, or damage to the mirror, it affects the image you record.

My EOS Rt could shoot at nearly 10fps, and the shutter response was so fast, there was a mode to artificially delay the camera when you fired the button.

,Sony introduced what they dubbed the DSLT (or just SLT) in 2010, with the Alpha A33 and A55 models.

This means Digital Single Lens Translucent.

What it is, its another pellicle mirror camera, but with a modern twist.

Light enters the camera and hits the pellicle mirror, which directs most of the light to the digital sensor, the rest to a set of phase-detect focus sensors just like youd have in a DSLR.

The camera does not have an optical viewfinder -- its an electronic viewfinder camera (EVF).

,So, advantages of any pellicle mirror camera in general, and the SLT in particular:n,No mirror blackout during exposure.

,Generally a much faster shooter than a conventional DSLR.

,No mirror vibration (only shutter), making a quiter camera with less exposure shake.

,Phase detect auto focus is continuous, which makes even more sense in the SLT, since that means its active for video as well as stills.

,nThe disadvantages include: n,Loss of the light directed to the viewfinder by the pellicle mirror.

,Any dirt on the mirror will affect both exposure metering and the final image.

,Theres no visual indication of a the camera having fired on a traditional pellicle mirror DSLR.



obviously, the SLTs may use the same tricks that mirrorless cameras use to indicate a shot has been taken.

,Pellicle mirrors tend to be very thin and fragile, and of course, theyre up front right behind the lens.

So theyre easily damaged, and again, that damage affects camera operation.

,So, DSLR versus DSLT, thats actually kind of the same question as DSLR versus mirrorless these days.

Im not sure the DSLT idea has much life left in it.

Sony invented this concept to deliver whats essentially a mirrorless camera with the AF capabilities of a DSLR.

There are currently a bunch of mirrorless cameras that have phase-detect auto focus integrated into the primary camera sensor, which pretty much removes the need for a DSLT.

,Given Sonys recent success with the mirrorless E and FE mount Alpha (formerly NEX) cameras, I would also be concerned about their long-term commitment to the A mount lens system.

They have not announced any discontinuation of the system, and in fact, theyre widely rumored to have new A mount stuff coming this year.

The choice between EVF and optical viewfinder may drive your mirrorless/SLT versus DSLR decision, factoring in most of the stuff that goes with it (mirrorless cameras tend to be smaller and sometimes lighter, DSLRs tend to get 4x-5x the number of photos out of a battery, etc).

In my mind, if youre leaning optical, go DSLR, if youre leaning EVF or just looking for a light-weight system, go mirrorless.

I dont personally see much to recommend DSLT any more.

,That said, I have a Canon EOS DSLR and several Olympus mirrorless.



I didnt make this a choice, and I did pick a mirrorless system thats much more compact and light than my DSLR system.

Perhaps an avid DSLT user will respond here and suggest other reasons to recommend the DSLT.