IMHO: The DSLR is a carry-over from the film camera days when the flip up mirror was required to view and meter the scene directly thru the lens. Today, the image can be directed electronically from the sensor to an electronic viewfinder (EVF) and do away with the size and complexity of the mirror box. This system is still being developed and will get better in the future, but already (IMHO) provides results as good as current DSLR systems. Of course, some people are wedded to their DSLR and will disagree, but I've seen no evidence to refute this view of the situation.
If there not a difference between a Fisheye and an extreme wide angle lens? A normal lens processes light rays linearly, and results in a representartion of the object. A Fisheye distorts the objective field by where it is in the field and there is not the proportional representation that a more usual lens offers.
Isn't it really unfair to compare the "sharpness" (however that is defined) of a fixed focal length lens with that of zoom lenses? A decent prime lens will almost always be better, cheaper, lighter and smaller?
One wonders, in these days of rapid advancement in electronic camera systems (of all types), whether a four year old review and rating will still accurately rate a camera system. Any rating criteria has surely been revised upward and what used to be an outstanding system would have dropped a few notches by today's standards.
Putting a 2X converter on a lens effectively spreads out the light passed by the lens, as seen by the sensor (or the film) it is halved. Essentially, some of the light is not used. So the lens aperture needs to be opened to compensate, to have the same amount of light on the sensor. All the optical effects resulting from the greater opening are incurred, e.g. some loss of sharpness.
I have several digital cameras, bought as the field developed over the last 10 or more years. But I started photography with film cameras, back in the day, mostly with Pentax SLR and have a variety of bodies and lenses, from fisheye to long telephoto, and some old zooms, threaded and bayonet. Does anybody know if anyone offers digital backs for these old cameras? Or have the lenses advanced so much in the last fifty years that these items are really obsolete? I appreciate that much of the automation available in current cameras (e.g. motor driven auto-focus) would not be useable. Thanks for any suggestions.
Does not the pixel count of digital light sensors put a lower limit on the resolution which can be captured in that media? Whereas a fine (usually slow) film can achieve a very high resolution, especially for the later highly developed (no pun intended) film types? Further, it is easy to use larger format films which work well with lens technology to record a lot of detail data (which is not available in the still-being-developed digital sensors)?
Two microseconds is too fast (too little time) to trigger any mechanical device.
The mirror flips up for exposing the film, not for measuring the exposure (as any schoolboy knows).
My experience with photography goes back 50 years, using film of course, and almost exclusively with 35 mm SLRs, mostly Pentax. So, I try to understand the new technologies using what I understand of the old. Two fundamentals elude me, however.
I dont understand still using the mirror box associated with SLRs. Film can be exposed only once. So a mirror is useful in formatting, focusing and metering the actual scene and then redirecting the light to the film for the exposure. But with digital sensors the metering and formatting functions can be done simultaneously with the capture. So what advantage is there to having the complexity, size and cost of a mirror box when a mirrorless layout avoids all that?
Secondly, a fundamental parameter of exposure was the film and its speed rating (DIN/ASA/ISO) which could be selected based on speed requirements, grain structure (fineness) and color qualities. But in todays digital cameras the sensor is fixed and not selectable. So why do we still input a speed rating? Surely there must be one rating which is optimum for the sensor fitted.
I invite responses which would educate me in these areas and relate them to my understanding of film photography.