Author Options:

Digital SLR? Answered

1. Why is the use of a mechanical mirror that has to flip out of the way still revered in Photography circles?

2. Why do Digital Cameras still use a mechanical shutter?

I have what they call a bridge camera that uses a small LCD viewer (as well as a large colour LCD screen) and as far as I can tell uses an electronic shutter.  It seems to work well and is reliable.



Best Answer 6 years ago

I majored in Cinema and Photography at Southern Illinois University many years ago so there is a pretty wide range of different cameras that I have played with over the years. I still think some of my best pictures were taken with a 4 x 5 view camera but hauling that around even back then was a chore. I didn't make my living at photography so I haven't done as much as Redesign but I have played with it more than most people. ( I wonder if he was in any of my classes)
Anyway something that those of us noticed who were majoring in photography then was that a large number of us took a rifle and pistol course (which helped with the phys ed requirement as it was in that department) and we all got A's in it. We were all crack shots, dead on marksmen. Even the ones who had never handled a gun before got A's after the first few practices. We concluded that it was something with the hand, eye, brain coordination that we all appeared to have. When you saw the sights line up you fired, something that normal people apparently have a slight delay with. The same is true with a camera. When you see your shot come together just right you react by triggering the shutter. Often you know if you got a good picture. There were countless times when I said to myself, "that's the one" after the shutter went off. Viewing what is going on through the lens directly appears to help with that reaction. I can take good pictures with a range finder or any kind of camera, (one of our class assignments was to construct a pin hole camera and turn in prints from it) but I still do better with an SLR. The mirror lets you see what the camera is actually seeing, not what the sensor is seeing. The camera I have now is a DSLR and I almost never use the LCD even though that is an option. I only fall back to that when I can't use to viewfinder like when the camera is on the ground.
There used to be a lot of debate about the mirrors. There was one school of thought that the mirror flipping up and impacting the frame caused vibrations which then caused fuzzy images. Today's mirrors are smaller, lighter and faster so that would no longer be a factor.
The mirror automatically flips the image so you don't need electronics to make it right side up. Electronics can alter the true image.
The mirror used to slow down the whole processes, but now they are faster. My camera is almost always set to shoot 3 pictures. It does one over, one correct and one under the exposure. I have played with making HDMI images where the three exposures are combined together to give a much wider (and often spectacular) range of tones and contrasts. My camera shoots those three images so fast there is almost no delay in between them, even though it uses a mirror.

So, I still think film cameras were better in terms of creativity and art, but the cost and difficulty of using them has put them on the road to extinction. DSLR is the next best thing that we have.
I don't know if you heard but Kodak has declared bankruptcy.

I won't even get into the fun and amazing things you can do in a darkroom.

A parting thought ---- Cameras are so common now with them being on everyone's phones, that real pictures and not snapshots, have lost their significance. Everything is automatic, nobody even thinks about the light or the color balance or the exposure. It used to take real skill to shoot a picture. And composition has gone out the window as well. When was the last time you saw someone with a camera phone concerned about what was in the background or how something was framed or the perspective or the depth of field. People take snapshots by the billions but very few of them take pictures. As a result they tend to just glance through things without looking for the elements that come together that make a good picture.
In several of my production classes in collage our pictures were graded in large part by the class. We had an easel set up with a spot light on it and each persons work was put up, one picture at a time. Then the instructor would start off the discussion usually with the question of who likes this? and then why, why does it appeal to you, or why not? It was a very effective way of delving into the heart of a picture and seeing if it worked, if it had a message, if it had a appeal, or if it was just a snapshot.

I am considering replacing my Fujifilm S5000 but am indecisive to go for a lower end DSLR of the Fuji film HS20EXR which at around £213 is about the same price I paid 7 years ago for the S5000.

It sports an equivalent 24mm to 720mm lens along with many other attractive features (minus the ability to change the lens.)

Review looks good - http://www.photographyblog.com/reviews/fujifilm_finepix_hs20exr_review/

AFAIK an entry level DSLR will cost me around £400 I was looking for a reason to spend a further £200!

Mmmm deep thought required.

thanks for your input any other comments welcome.

This is going to turn into an instructables longest answer contest.
Something I discovered after I got my DSLR is that there are now a lot of lens adapters being made. You can get adapters for older lens's and fit them to the new camera's. The electronics don't work so you don't have auto focus or f stop control but you can do all of that manually. I have this monster 300 MM f4 tele lens that I had given up hope of using again but with a $5 adapter I can now fit it on my DSLR. So that is a plus for removable lens camera's and a thank you to the Chinese who are churning out adapters at reasonable prices. (You can find them on E bay) So getting a low end DSLR might open up a new world of possibilities for you.
My old lenses are the Pentax screw type as well as my camera's. There were 2 choices of mounts back then, the bayonet and the screw type. I went with the screw type even though it was slower to change. One of the reason was because of a little trick that we learned. With a screw lens you could partially unscrew the lens so it wasn't seated tight and change the focal length of the lens slightly. Everything was manual focus and this gave us a little bit of play. When a manufacturer makes a lens they set the zero or infinity setting in the factory. We found that sometimes it was off. So there were some lenses that were out of focus at the infinity mark which meant that at a wide aperture they were always fuzzy. With a screw mount you could compensate for this by making a paper or cardboard ring and slipping it over the lens mount. With a bayonet mount you were stuck with it. I actually removed an adjusting ring from my big lens so it focuses past the infinity mark. So for an infinity shot you go all the way past and then turn it back until its sharp. Anyway, a camera that has a lens that you can change gives you a lot of possibilities including things like extension tubes.
As to shutters:
I don't know if the new shutters are different but 35 mm camera shutters have been elector/mechanical for a long time. They are also 2 stage shutters which most people don't understand. The shutter works by moving a slit across the film. It starts when the leading edge starts to open and moves across the film. Then depending on the speed set, the closing edge is released and follows it. So part of the exposure time is actually controlled by the distance between the open and close edges. The best example of this is to look at a train passing at a crossing. The gaps in between the cars are like the shutter in the camera. You never actually see entire scene on the other side at the same time. You see a slit of it as the gap moves across. Then along comes a flat car and you can see everything. A typical shutter is only fully open at speeds below 125 or for some 1/60th. This is why you need to drop to that speed to take flash pictures. If your shutter is not fully open you will get only a part of a picture when the flash goes off. In order to have this kind of exposure control you have to have some kind of mechanical shutter. The timing of it is electronic but the actual blocking of the light has to be mechanical. Any other type of shutter can leave vignetting. As an iris opens and closes the center of it will let more light through than the edges will. This will make the middle of the film exposed longer than the edges. The slit shutter was developed to solve this problem when film speeds became fast enough that this tiny difference became a problem. All large film cameras with fast shutters used this technique. It was only the little box cameras with fixed lenses that used an open/close shutter. Except for view cameras which have the shutters in the lenses. With these the shutters are so far away from the film that they don't usually have exposure problems.
For a conclusion, I don't know if the DSLR uses a moving slit shutter or not. I haven't taken one apart yet. Other camera's like phone camera's use an electronic capture. They don't really have shutters, the electronics grabs the output from the sensor at that instant and records it. But that also might depend on the brand and design, things are always changing now.
And that is my last point. Years ago a good SLR camera would last for many years. They didn't become obsolete for a long time. The basics of them stayed the same. Now, the camera I bought 1 1/2 years ago is out of production. It is already past the point of fixing it if something goes wrong with it. That kind of bothers me. It takes a while for you to really adjust to a camera, for it to become an extension of your hand and eye. It has to become habit for you to hit that shutter button, you can't stop and think about it or you missed the moment. Everytime you change to a new one you have to go through that learning process all over again. That might be Ok for computers and phones but for cameras that you need to be able to use with out thinking it's a bit more difficult.

Very interesting Vyger. I wanted to comment on your statement "when was the last time you saw someone with a camera phone concerned about what was in the background or how something was framed or the perspective of the depth of field". Normally I'd agree with that, but in my case I haven't the money to afford a good DSLR, and when I needed a new mobile, I opted for one with a 3.2 Megapixel Carl Zeiss Tessar 2.8/3.7 Camera with flash. I enjoy taking photographs, and surprisingly enough, this phone takes some amazing images. I do obsess over the composition, and go for good lighting and perspective on my images and where the camera fails (or I fail), I'll use PS to enhance and improve the images further.

Well thats my 2-cents anyway. As much as I'd love a good DSLR, this has got to do. :)

I did not intend to imply that only DSLR camera's are good camera's. There are a lot of good camera's, including phone camera's out now. And DSLR's are probably overpriced, I could not afford one for a long time, and the one I have now I bought refurbished for almost half the price. Also, I still take a lot of snapshots, but every now and then I get a good picture.
RickHaris's question was why they are revered. That is the distinction I was trying to make.
My son has taken up the torch, or gotten the addiction depending on how you look at it and he has better camera's than I do now. He is the one who started working with HDMI.
Below is one of his pictures that is an exaggerated HDMI picture.(I hope he doesn't mind me posting it) It almost looks fabricated, but it is a composite in this case intended to bring out the dynamics in the clouds.


If I understand you HDR takes 3 separate pictures and your son gets to
pick an individual, or a mix ?

You need a minimum of 2 images and you can use more than 3, 3 appears to work best. Depending on the software, and that has become much more advanced lately, you can filter for different things or enhance different things.
There are quite a few instructables on it, just do a search for HDR photos. This is one -----
Something we found interesting are the effects from movement. For instance if it is windy and the grass moves in between exposures it creates a kind of ghosting effect that looks very strange. We were going to try some rippling water ones but haven't had the chance to do it yet. Also using a polarizing filter in addition to changing exposure should make some interesting effects.

Beautiful image, but I think you mean HDR (not HDMI). :)

Yep, HDR, I'm getting my letters mixed up again.

Thanks Vyger for taking the time to reply - I have an Olympus OM10 and several lenses for it - Having had the camera for many years now - It still works perfectly,

However for convenience as I take my pictures for my pleasure I turned to digital cameras.

I have had my Fuji S5000 for several years now and like it's handy zoom lens 37 to 370 mm , I like the weight and the fact it has a real view finder (as well as the LCD screen) However I am not so keen on the 5Mp resolution and might like a longer lens other than that it works fine.

I have been satisfied with the general quality of the picture although cropping and expanding tends to show some "grain". I rarely use the manual functions sticking to the pre set auto mode unless I am looking for a particular effect.

Trouble is there is a lot to balance - Cost against use, Versatility against convenience, My other half's opinion on what I should spen money!!

Again Thanks for the detailed reply.

All of the digital cameras I have had so far have been Olympus. (I am on my 4th one) . I have been impressed with their optics and so far they are usually more reasonably priced than the others. My son uses a Canon and I looked into getting one but then got this one instead.
It had a 2 lens set and all the features I was looking for and was only $460 at the time, refurbished. it has worked flawlessly so far. There are features on it that I still have not tried.
I found one on the UK eBay
But that looks like a steep price for a used camera and no extra lens.
Anyway, in my experience the most important thing is if the camera fits you, serves your needs and is something that you are comfortable with. One of the things I really like about Olympus so far is that they fit my hand just right. So, like you said, lots of things to consider. I know Olympus has a whole new line out but I have not read up on them.

Thanks for posting the Ebay link - I also think they are asking a lot for an unknown second hand camera - In addition I don't trust someone who doesn't take their own photographs of the actual model - I think they were showing stock internet pictures.

The pondering continues.


6 years ago

Slowly moving to iPhone imaging with edit features built in and  email
to my computer.
Regarding mass of camera, I use the saddle on a six inch tripod works great for me..




Extensive testing shows that the eye line viewer (not the LCD) gives an (almost) perfect frame to what the lens sees. i almost never use the LCD screen for those very reasons.

I also used and still have an excellent SLR that in many ways I prefer to my digital camera (although not the mess of film processing) I would have thought an engineering exercise to cover the CCD sensor whent the lens was removed would be easier than fitting a precision shutter.

I have little experience with a DSLR but the only thing I can put my finger on is the DSLR doesn't have the delay between the finger press and the taking of the photograph - But then again I also know that many of the high end digital cameras also reduce this to virtually nohting.

I think I can give you some reasonable answers on both of them.

1. I carried a film SLR almost every day since 1970. Those of us who used them like the feel of the. The noise they made when taking a photo. At the time they were the only cameras where you could use interchangeable lenses and still get a true sight picture. Twin lenses and rangefinder cameras have a parallex error. Field (folding) cameras with a ground glass were too large to carry every day and the image on the ground glass was upside down.

There are some newer cameras that may be able to replace the slr camera with the mirror.  One thing that may hurt them is it is un-natural to view the screen away from the face.  With an slr, holding it to your face to look thru the viewfinder steadies the camera.  Holding it away to look at the screen on the new cameras don't do that.  But the steady cam circuit may eliminate that problem.

2.  Some types of camera sensors are like your retina and can be desensitized if exposed to a bright light.  With a mechanical shutter, the sensor is kept dark until needed.  There is a very good, very expensive camera built for astro-photography that has no shutter.  The exposure is controlled by a laptop computer that is running the tracking mech. on your telescope and timing the exposure.

On the digital slr, the shutter helps keep the sensor clean since it's open the the atmosphere when changing lenses.

"true sight picture" would be a right answer for me.