Reflex means the use of a mirror in the viewfinding process. SLR stands for single lens reflex. The term tlr means twin lens reflex - although there are far fewer of them today than during much of the later film days. The tlrs generally had a finder which was used by looking down from above to a camera held at about the waist level, and the camera generally had what appeared to be two lens, one over the other. The mirror was generally fixed in place and was mechanically simple. The advanced tlrs had adjustable focus and some even had replaceable or interchangeable lens sets.
The mirror is flipped out of the way to allow the light to hit the shutter then film or sensor. It's more compact but more mechanically complex. The primary advantage is that you are seeing the light that the film or sensor would see. Other viewing systems show a slightly different view or light path and this can cause some alignment (parallax) problems for some subjects. The closer the subject, the more parallax.
As with any optical finder, you see real-time - there is no delay for the sensor to see the light, the processor to read the sensor, then display it on a separate finder display. Focus determination/exposure determination is enhanced. And with current technology, the focus determination is often faster for auto focus cameras. You should consider an slr camera when the fastest reactions, yours and the cameras or the most critical focus issues are important. Supplementing that are the ability to select what may be more appropriate lenses for the job at hand and that current dslrs use larger sensors than most other digicams and therefore have much better lowlight performance.
Larger sensors or interchangeable lenses coulb be applied to non-slrs but generally haven't been. So, while the current state of the camera as system, slrs/dslrs tend to be faster, more sensitive, and more flexible, that comes at generally higher costs for the cameras and other "system" components, especially lenses...
Hi JEulrich, You may find an introduction to DSLR cameras at:.
Http://www.neocamera.com/guide_dslr_basics.html It lists 10 important thing particular to DSLRs and some.
Advanatges and disadvanatges when compared to fixed-lens.
Digital cameras. - Itai..
Thanks for the excellent email. It was very helpful and has given me some good info to consider as I look to upgrade my camera.
Best regards, Joe..
Thanks so much for the great link. Very informative and helpful. I'm looking to upgrade and trying to choose between an Olympus EVOLT E-500 and a Nikon. Every bit of info is appreciated. Best regards, Joe..
The main weakness of the E-500 is it's high-ISO performance which is.
Not as good as other DSLR cameras (but it is better than nearly all.
Fixed-lens cameras). Otherwise, it is very full-featured, including.
Built-in sensor cleansing technology. So if you do not need clean noise free pictures above ISO 400, the.
E-500 would be an excellent choice. Otherwise, you'll have to look.
Elsewhere. - Itai.
I would not be put off unduly by the noise factor. Ive had one for a few weeks now and I've been blown away by it's performance and value for money. Checkout my blog if you want to see example shots (including some exhibiting noise - "Mine's a pint" is one to look for) - they are all posted in reasonable resolution. There is also an E500 discussion forum on this site, which has a lot of useful views. Ham http://londondailyphoto.blogspot.com..
I remain amused at the fact that SLR in the digital camera world means "has interchangeable lens facility". Perhaps the pundits need to come up with a better term as it is fair to say that any camera with a screen is effectively an SLR. And as you rightly said, the better TLR cameras had an interchangeable lens capability. We could go for PAS for the lower end (point and shoot) and ICL for cameras with interchangeable lenses but what do we call those like the Fuji 52(6)00 which are clearly not PAS nor are they ICL?..
Hi Robin, Actual SLR means the same thing in the digital world than the.
Camera world. An SLR is a single lens reflex. The point is that.
There is a single lens on the camera at a time (no second lens.
For the viewfinder) and the light-path is reflected (either using.
A prism or pentamirror). It turns out that all SLR digital cameras.
Have interchangeable lenses, but I think that HP had one several.
Years ago which did not. The LCD screen display is usually seen.
As a TTL (Through-The-Lens) display, but not a reflex. There are many people out there who are waiting for an.
Interchangable lens camera with an EVF rather than a reflex.
Viewfinder so that they can preview exposure more accurately.
At the expense of focus (with the assumption that AF tends to.
Work better that AE). Middle end digital cameras are called by many names: digicams,.
Brige-cams, all-in-ones, prosumer cameras, etc. I prefer to.
Simply call them fixed-lens-cameras. For now since there is.
No fixed-lens digital camera that is an SLR, it sufficiently.
Descriptive, but that may change one day. Then we may have to.
Call such a camera fixed-lens EVF or fixed-lens TTL. - Itai.