So, being largely a novice in the world of Reflex cameras, I was talking with a friend who mentioned this issue. While he is definitely more expert than I am, none of us has any accurate data, and we are curious.
Is it (still?) true that DigitalSLR are slower that analog SLR in taking pictures, precisely since the time yuo push the shutter button to the time the image is captured? In other words, do you really capture what you see when you push the shutter button, or at least are you as fast as old analogs?

Usually reviews I've read, dpreview ones in particular, measure the time needed to take the first shot in terms of OFF-Shot. In other words, they include the time needed to power the camera on.

I can understand there could be a delay there compared to analog reflex (?), but I can also accept the solution of keeping the camera in Stand-by and pay the price in terms of battery life.

But, other than that - assuming current cameras are still affected by this - is there any other soruce of slowness?

I would tend to say no, and this is my reasoning. As you can see though, I am missing some data.
1. Disabling AF, I suppose that pushing the shutter button in a dDLR is like pushing the button on a SLR: shutter opens and light poors in.
2. Light reaches the sensor, which I would guess to be much faster than the film in capturing light and retaining it to replicate how exposure changes in time.
3. Processor needs to take data collected by the sensor, produce a file out of it, and store it in RAM first, memory card then. Am I missing something?
If not, I am assuming that delay can only be generated here. And the fact that the Canon 7D, for example, uses two image processors instead of one, makes me think that there is a need for speed there, especially, I suppose, with larger nr of bits needing to be processed when using high resolution sensors.

So, if I am correct in this simple thinking, are current cameras (image processors) perfectly comparable to old analogs? More realistically, are they all, or just some of them?

What do you guys think / know about this?

I don't know about all brands, or all models.

But for the top-of-the-line film and digital cameras (professional boat anchors) from Canon, the 1V (film) and 1D (digital), the 1D is quicker.

AF cameras are slower than non-AF cameras, film or digital. Turning AF off closes the gap, though.

Cheers

I am, once again, not an expert, but I cannot imagine how film couldn't be faster. You're opening the shutter for the same amount of time (assuming the same film/sensor speed), but the film records that data directly due to the photons affecting the chemicals on the film, whereas the sensor has to do the same thing, plus pass that information on to a bunch of electronics, which in turn do more processing.

However, there are really at least two questions here. The one I just answered is "how long does it take the camera to record an image?". The next is "would the image I captured be the same between these two cameras?". I think the answer there is "yes". I don't see any great reason why there would be a significant amount of difference between the time you press the shutter button and the shutter actually opens, and I've already pointed out that the shutter is open for the same amount of time. Since neither camera can record images at any time when the shutter isn't open, that would seem to indicate that they'd be taking the same photo.

(Actually, there might be an electronic delay on the digital camera, as it might have to tell the sensor and related electronics to get ready, while the film is always ready. That said, I imagine that mechanical linkages would make that delay irrelevant.)

Then there's another question, which is "how much longer until I can take another photo?". I'd imagine that the digital could come out ahead here, as it doesn't have to wait for the physical movement of a piece of film. There are probably other factors that are more relevant, though.

Yes, my question was precisely: "would the image I captured be the same", the variable being TIME and not QUALITY, to be accurate.
In other words, will I be capturing the same moment in time?

And, you have a great point there in answering this question. As a silly novice, I was forgetting a quite obvious piece of information: the shutter >>stays open<< for time X for both cameras, and that's decided by the operator.
My thinking was wrongfully based on the inconscious assumption that the shutter would close "when done", which make no sense in a camera.

So, yes, the only parameter left, as far as I can tell now, is whether the shutter-release button in dSLR does more than mechanically opening the shutter, or not. If not, there must be no difference.

Thank you!

Press the button, the camera takes the picture.
The time between those two events is called "shutter lag".

An old-fashioned film camera used mechanical linkages from that button to the actual shutter. But for the past 25 years, nearly all SLRs have had electronic linkages, film or digital.

Shutter lag is comprised of AF delay, AE delay, processing delay, and shutter actuation delay. These are all the same between film and digital, or at least should be all the same.

So film and digital ought to be pretty much identical here, on similar platforms.

Except that every 36th 37th frame (or less), there's a 1+ minute delay before a film camera can take the next shot. Digital cameras only hit this delay once every several-hundred (or several thousand) frames.

The next factor is shot-to-shot delay. Digital wins here, hands down: no mechanical delay while the film is wound to the next frame. The result is that digital cameras boast FPS (Frames per second) way in excess of similar film cameras.

And don't even get me started on shot-delay when changing ISO (film speed). At best, it's perhaps 5-10 seconds using film, when one switches from one camera body to another. At worst, we're talking minutes to change films. With digital, the delay can range from zero ("auto-ISO") to perhaps 5 seconds of fumbling with controls.

Cheers

There should be a moody index as well. I had a couple of minolta aslr cameras that were very fast, when they were happy. But if they thought all the settings were not perfect, they would just refuse to take the picture. I hated those cameras...

All my digitals are this way, they get pissy and refuse to take pictures if all is not perfect. I would love a camera that just takes the shot when I push the shutter button, correct settings or not.

I don't know too many ways to set up my D300 to prevent it from taking a shot when the shutter button is pressed. One sort-of those way is setting into self-timer mode - but it will still take the shot - after a delay.

Canon DSLRs (or at least the ones I have used), when in Program, Aperture or Shutter modes will refuse to take the shot when the shutter speed would have to exceed the max speed. With auto focus on they will also refuse to take the shot if they have failed to get a focus lock. They will also refuse to take the shot in many modes if the flash is raised and the shutter speed needed would exceed the sync speed.

I'm guessing the Nikons and other DSLRs behave similarly ?

But of course is that is a problem you'd just switch to manual exposure and turn off auto focus.

Yes, and that "+" can be very long, I suppose, if you're in a harry and drop your camera, or the film, or you mess it all up somehow.

Thank you all, guys, this all makes very much sense and answered my questions.

I noticed that too, but was not sure if I was doing something else wrong. It is a bit annoying, I have to say. Again, I guess that one gets used to that. I too have only used Canon DSLR, though, so I don't know how Nikons behave.

Annoying ? Why ?

The whole point of the Program, Aperture and Shutter modes is that exposure is automatic. When you select those modes you are saying "please get the exposure 'right' for me".

Say you have the aperture set to say f/2, the ISO set to 400 and it is a nice sunny day. That could mean that the shutter speed is 1/8,000 of second or some equally high number.

The camera could either just go ahead and take the shot at 1/4000, resulting in an over exposed shot or it can not take the shot and indicate why it can't (i.e. flash the shutter speed on the display). I for one would prefer it to alert me to the problem rather than just slavishly taking the shot.

If you want to take a shot regardless of how it is exposed, there is always full manual mode.

A third choice would be to allow you to choose what it should do in that situation via an option. Some DSLRs may well do that, I've only ever used a couple of Canon models for any length of time, so wouldn't know if any did.

Don't get me wrong, I am not saying it is the Camera's fault.

The behavior I would have consider "intuitive", as a novice, is to offer me an option: wait for the camera to complete all automatic adjustments when the button is half pressed and push the button down only after the OK beep is heard, or not wait for the beep and go all teh way down with the button before the beep, taking a "wrong" picture.

Having a different expectation, I felt frustrated when, in "wrong" exposure/aperture conditions, I could just not push the button and "see what happened", which was my approach to begin with. Of course, I resorted to manual mode then.

Sorry, I suppose I wasn't taking into account purposely setting up the camera to fail, such as not making any shutter adjustment in shutter priority or aperture adjustment in aperture priority, trying to exceed the limitations of the software. In full program it should be able to make the necessary adjustments to always take a shot. Though to be sure, one can also use auto-ISO which makes even more automatic in the vein of a P&S.



This is an option for Nikons in at least the pro-sumer range, such as the D300. I'm pretty confident it's available at least in the D70/D90 class machines too.



Hmm, this one I can't recall, but it too might be influenced by some configuration setting as well.

I think that once you're used to the limitations of the camera and more so the relationship of sensitivity, shutter and aperture (your calculated exposure), these situations will be very very rare.

Why not both? I can't imagine an instance where a bad photo would be worse than no photo.

I can, for me at least. When you have forgotten you have it on too high and ISO, are quickly taking a shot and not bothering to review the shot. I'd far rather have the camera clearly let me know by not taking the shot so I can fix the problem.

My camera, if the exposure is outside the camera's limits to set correctly, just changes the information in the viewfinder to red to let me know there's a problem, but it nonetheless takes the picture. This seems to me to be the best compromise.

tanstaafl.

Nikon, at least, lets you set a variety of different autofocus policies with regard to what happens when you want to shoot at the precise moment when the image is out of focus. I've got mine set such that it always takes the picture immediately and autofocus is completely disconnected from the shoot button. Instead, I use the "AF-ON" button the back to pick my focus, then reframe the shot. (Exactly like I used to do with manual focus cameras and that goofy split-screen focusing gizmo.)

Yes, this is best. I tend to take pictures of folks doing things, so I don't always have time to set the camera up properly. I would rather have a crappy pict than the memory of a defiant camera.

I miss a lot of shots because of my cameras these days. That never happened with the AE1...

Maybe I should look at your camera, it seems a good all around choice.

You are assuming light meters are always correct. They are not, in fact reflected light meters are very easily fooled and tricked. For instance, what if you were trying to take a picture of something in a snowy scene with a ISO of 400 and aperture of f/2. It could well be that the correct shutter speed to render the snow white would be less than the camera's maximum shutter speed, however the light meter would think the correct shutter speed is 1/8000 (which few if any cameras can do) because it tries to render the snowy scene a neutral 18% gray. Blind reliance on light meters is a very bad way to take pictures- you can almost always get a better picture if you carefull spot meter the scene or use an incident meter. No one does this anymore in the age of digital because they can assume "I can just fix it later"- but they actually can't because of digital's low dynamic range..

I'm not, hence my quotes around the word 'right' in the phrase "please get the exposure 'right' for me".

But then you asked the camera to prevent you from taking the shot if the exposure is not "right". So the camera should trust it's light meter more than the user?

I suppose you could design the camera to force you to take the shot in manual mode- but that's not exactly elegant behavior...

No I didn't.

I said that if when in Aperture priority the camera's light meter decided that the shutter speed needed to be higher than the max shutter speed the camera is capable of then I wanted it to make me very aware of the fact (but not taking the shot) rather than just taking a shot at the max shutter speed.

If I want to second guess the light meter because of challenging lighting conditions or dynamic range, I'll be in full manual mode.

IMO, that's the only way to manual focus and without it, manual focus is almost useless. So I never ever manual focus with my Nikon D300.

Only way? I kind of like what my camera does. If I am using manual focus, as soon as I move the focus ring, the center of the image in the viewfinder is magnified eight times. This allows very precise focusing on whatever element of the picture is most important. When I stop moving the focus ring, the viewfinder reverts to normal view.

FWIW, I always use spot metering and (when in auto-focus mode) spot focusing. Another trick I nearly always use is to gauge exposure by what the viewfinder shows. When the shutter release is pressed halfway, the viewfinder image darkens (or lightens, as the case may be) to show what the actual exposure will look like (something a DSLR with optical viewfinder can't do) and locks the exposure. If that image in the viewfinder is not what I want, I move the spot focus/exposure point to a lighter or darker portion of the image and lock that exposure. I might do this three or four times (it takes less than a second per try) until the preview exposure looks like what I want, then press the shutter release all the way to actually take the picture. The metered exposure gets me in the ballpark, but I make the final adjustments by eye. Depending on what operational mode I am using (shutter preferred, aperture preferred, or program auto) the camera adjusts to compensate for how I want the picture to look. Sometimes I'll set the camera to do three-shot bursts, one under-, one normal-, and one over-exposed (according to what the light meter is telling it) in combination with the half-shutter-release compensation described above.

tanstaafl.

You can't magnify an optical image in the same way though. If your eyes are the least bit off, even if only temporary because some dust blew in them, it's a complete PITA to focus manually without the prism on the focus screen - though my old Minolta actually had this feature on a specific lens, go figure (I have no idea how that was accomplished).

FYI, that's called bracketing.

Yes. Do other cameras have that burst mode where it takes the three shots in less than one second with the bracketed exposures? I can adjust the degree of over/under exposure in 1/3 f-stop increments up to +/- two stops. In other words, as much as two stops under and over, or as little as one-third stop under and over.

tanstaafl.

Yes, many do, especially from the film era.

Bracketing, yes, but not necessarily the burst part that Doug refers to. In the (D)SLR world, bracketing and "burst" (or continuous mode) are generally separate features. If you choose, you can use them together, giving what he describes, but you could also choose to shoot your bracketed frames one at a time

That's called a split-image rangefinder. A lot of former full-image Rangefinder users (read: mostly Leica users) wax poetic about them and mourn that no decent digital cameras have them today. They are kind of nice when you get used to them- especially full image rangefinders like the Leica's of old.