How does this work, then ?

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Fox_one

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I do hope the Mods will take kindly if I have put this question in the wrong place.

I've used a camera for many years. I got used to setting Aperture and shutter speed for a given ISO (or DIN) rating of film, both two-and-a-quater square and 35mm. I spent hours in various darkrooms getting the FP3 or HP4 wrong and eventually getting some right. :bang:

Now I have a digital and, I'm told, quite a good one. But one thing baffles me.
On a film camera, you can see the aperture ring on most lenses. Some even had a shutter on the lens !. :thumbs:

So where is the aperture ring on, say, my Canon EOS400D ?
OR, is it an electronic fiddle by the camera's 'brain' ? :thinking:
 
In EOS lenses its all controlled from the camera body. Its all electrical doohickeys and microchips etc! ;)
 
On a 400D you hold a button down on the back and rotate the dial behind the shutter to adjust aperture in manual mode (or exposure compensation in the priority modes). It's the button with a +/- icon on it to the left of the rubber grip that your thumb usually rests on.

On the higher models other than the 60D there's a wheel on the back of the camera that handles aperture in manual mode (or exposure compensation in the priority modes).
 
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Fox_one said:
So where is the aperture ring on, say, my Canon EOS400D ?
OR, is it an electronic fiddle by the camera's 'brain' ? :thinking:
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If you take the lens off the camera and look through it it should be fully open. On the side of the lens which goes towards the camera there will be something which the camera moves in order to close the aperture. On Nikons there is a small metal post. If you touch this with your finger and move it the aperture closes. I would assume that this is the same for Canon cameras or alternatively there is a motor and a contact. Whichever way the lens does it it still works like the old film ones.

The reason for the lack of an aperture ring is because the control is now on the camera and it can cause a conflict if there is a control on the camera as well. This is why some Nikons have a fully open aperture LOCK button.
 
Why not come to the next local TP meet, there's a link in my signature to the thread for Jan meet :thumbs: there will be at least a couple of 400D users there :thumbs: and we are all happy to help you get to grips with your camera :thumbs:

But as has been said you use a button on the back of the camera and the wheel on the top to change aperture or if in Av only the wheel on the top :thumbs:

Welcome to TP

Matt
MWHCVT
 
menthel said:
In EOS lenses its all controlled from the camera body. Its all electrical doohickeys and microchips etc! ;)
Click to expand...

It is my understanding that the doohickey was phased out on earlier models due to limitations in luminance and to a lesser degree, chrominance performance and has now given way to the inverse-splined thrungebucket.
 
Oggy said:
It is my understanding that the doohickey was phased out on earlier models due to limitations in luminance and to a lesser degree, chrominance performance and has now given way to the inverse-splined thrungebucket.
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I'm Loving this:thumbs:.

Regards.
 
Well, my lens is an EF 70-135 and there's no aperture thingy therein.
So I guess that it's "all done in software" which is a bit of a bu**er.

Ah well, Plan B, then . . .
 
The aperture isn't done in software just the operation. The EF lens mount is electronic, stop the lens down and press the DoF preview button and you'll be able to see the aperture blades in the lens close.

When AF came out, Canon had put a lot of effort into really smart cameras without AF and rather than rush to market with a compromise design, they decided to ditch their entire catalogue and reinvent their SLRs from the ground up. So there's no mechanical connections between camera and lens, allowing the lenses and cameras to be improved without any further redesign, whereas Nikons incremental changes mean that some lenses sort of work with some of their cameras.
 
Fox_one said:
Well, my lens is an EF 70-135 and there's no aperture thingy therein.
So I guess that it's "all done in software" which is a bit of a bu**er.

Ah well, Plan B, then . . .
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ditch the eos get a nikon f film camera and come and join us in the film forum
:thumbs:
 
donutagain said:
ditch the eos get a nikon f film camera and come and join us in the film forum
:thumbs:
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Or better still, buy a Canon to M42 adaptor, and go and buy loads of cheap manual focus lenses, with lovely aperture and focus rings, and other widgets, thingummies and no doohickeys or chips.;)
 
I don't understand what's going on here???

What's the difference between turning an aperture ring on the lens and turning a thumbwheel on the camera?
 
The Boz said:
I don't understand what's going on here???

What's the difference between turning an aperture ring on the lens and turning a thumbwheel on the camera?
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You get used to one way, and then have to get used to another. Simples.
 
Oh I see, makes sense now ha ha. Sorry if I sounded like an a*se
 
Alternatively, what you describe in your original post was using the camera in manual mode (you still can) but you can also use it in shutter (or aperture) priority mode. In shutter mode you select the shutter speed and all sorts of wizadry happens in camera ,using light meters and other such cleverness, the camera then establishes what aperture it needs for "correct" exposure (except its not always correct of course, think strong back lighting etc) and as the mirror leaps out of the way electricity runs into the lens and the aperture is stopped down depending on how much electricity it gets thrown at it by the battery, much like the old fashioned mechanical linkages of days gone by when dinosaurs ruled the planet (or apparently the Nikon way of doing things since time began - and hasnt changed :) )

In aperture priority its similar, in full auto mode its even more clever and you neednt worry about anything at all (other than pointing it roughly in the correct direction and pressing the shutter release at some point, latest Nikons even do that for you according to their advert).

I came through 6x4.5, 35mm and FP4 too, fun wasnt it?

Matt
 
Thanks for the helpful (and amusing) replies.
What's getting to me probably isn't vital; I'd just like to understand what's going on!

Ah well, back to the Operating Manual
 
Fox_one said:
Thanks for the helpful (and amusing) replies.
What's getting to me probably isn't vital; I'd just like to understand what's going on!

Ah well, back to the Operating Manual
Click to expand...

I don't understand this anymore, amongst all the fun you've been told exactly how the aperture operates.
 
I think the op is very confused here though I'm not sure why!

You can adjust the aperture on the 400d as you can with any digital or film body.

You just have to turn a dial on the camera body rather than an aperture ring on the lens. I dont see the issue!
 
Oggy said:
It is my understanding that the doohickey was phased out on earlier models due to limitations in luminance and to a lesser degree, chrominance performance and has now given way to the inverse-splined thrungebucket.
Click to expand...

Well, it was about time. It had been over 30 years since the doohickey had replaced the contersprocketed thing-a-me-bob.
 
My thanks for the amusements, folks.
My question could, I guess, have been phrased better. (Sorry;I was raised as a techie!).

I wanted to know about "aperture" in an electronic sense as, despite my best endeavours I cannot see an aperture ring and thus wondered if it was/is an "electronic fiddle".


PS.
I wish I could afford a Nikon F. . . . . .
 
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I try to think about things simply too else I get confused, this is how I believe it all fits together....I think the thing to remember when comparing to an old fashioned camera ;) is the camera keeps the lens aperture wide open (so your view is as clear and bright as possible through the view finder) until you decide you're ready to take the picture....pressing the shutter release button makes the camera focus (unless you've set your lens to manual focus)..makes the camera work out the correct exposure for whatever its pointed at (based on the settings you choose for metering or whatever you set if in manual) this all drives the decisions needed to get the correct exposure. Camera in Av mode - you will have set the aperture so camera chooses speed and iso, camera in Tv mode, you will have set shutter so camera chooses aperture and iso, in manual mode youve selected it all so camera just uses those settings.....once these calculations are done and you press the button down all the way, the camera closes down the aperture then opens and closes the shutter, exposing the sensor which receives the light and depending on the ISO selected that information is reacted to accordingly. Key thing different to an old camera is the aperture isn't physically shut down until you press the button.

Not wishing to confuse things, but as has been mentioned, you can press the button on the front of the camera next to the lens which will close down the aperture to whatever you have set at that time so the viewfinder is stopped down thus showing you what the effect will be, but Ive yet to find a real use for this.

I know there are probably other bits and pieces, but hopefully that helps..
 
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arwesa said:
Not wishing to confuse things, but as has been mentioned, you can press the button on the front of the camera next to the lens which will close down the aperture to whatever you have set at that time so the viewfinder is stopped down thus showing you what the effect will be, but Ive yet to find a real use for this.
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It's called the Depth of Field preview button and it does indeed show the change in the depth of field. However it darkens the viewfinder sometimes to the point where you cant see enough detail to assess DoF.:cuckoo:

However if using Live View some cameras will brighten the screen to take account of this, allowing very accurate prediction of DoF whilst setting up the shot.:thumbs:
 
Yeah I knew that, but just never found it really useful :-s ..yet
 
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