apeture rings

DanielB

i guess i never really realized it but modern lenses don't have apeture rings like the old manual cameras did.... what happend to them and how do the lens mechanics work to create the effects that are characteristic of the 22 apeture and so-on:dunno

thanks,
Daniel

Red Bull

I believe it's all just electronically controlled. Instead of a mechanical device that trips the aperture, the camera tells the lens what aperture to snap to, and it closes to the aperture you chose. There is still an aperture diaphram (sp?) in the lens, if that's what you were asking in your quastion.

Nikolai

What Steven said..:-)

Red Bull wrote:

I believe it's all just electronically controlled. Instead of a mechanical device that trips the aperture, the camera tells the lens what aperture to snap to, and it closes to the aperture you chose. There is still an aperture diaphram (sp?) in the lens, if that's what you were asking in your quastion.

In fact, you guys should appreciate that, since it gives you an ability to fcous wide-open and the apreture value is only set during the exposure itself (most sub-pro and pro cameras have a dedicated button to check the actual exposure/DOF)
In the days of yore you'd have to set aperture wide (otherwise it was very dark - it's an SLR, right), focus, then set the aperture to what you wanted and only then press the sutter... Oh well, those were the days

HeldDown

... unless you had the sexy Pentax Takumars that had a DOF-Preview ring linked to the aperture ring, so you could set your f/stop, spin it wide open, focus, and quickly spin it back to its original setting. Bee-youtiful!

I realized no one has fully answered Dan's question.
With the old-style lenses (or even a lot of new, non-Canon lenses) you can manually set the aperture by using the Aperture Ring. New lenses automate the aperture the same way they automate focus: instead of you physically spinning the ring, the lens has motors that are instructed by the camera body WHERE to spin to. Aperture control is similar: you tell your camera what f/stop to shoot at (example, f/8). The camera says "Okay, cool, the picture's going to be shot at f/8." However, it leaves the aperture wide open at that point, so, like Nik said, you can focus nicely -- because, the wider open the aperture is, the more light enters, and focusing is therefore easier -- even for the camera (this is why stacking teleconverters on slow lenses can suck -- some bodies, like most EOS bodies, require a minimum aperture to focus accurately -- I think it's f/8 -- beyond that, it's just too dim to do it right.). So, when you press the shutter button, the lens very quickly stops down the aperture blades to the "f/8" setting. When the shutter closes again, it opens up the blades again.
Try setting a piece of your glass to around f/22 or so, and going to Bulb mode. Grab a penlight or a maglite, and shine it straight into the lens. Press and hold the shutter button. You'll see the aperture rings close to the f/22 for the whole time you've got the shutter depressed. Then, you'll see them go back to wide open.

Hope that helped!

jimf

Nikolai wrote:

In the days of yore you'd have to set aperture wide (otherwise it was very dark - it's an SLR, right), focus, then set the aperture to what you wanted and only then press the sutter... Oh well, those were the days

While admittedly my oldest SLR is only twenty six years old, every 35mm SLR I've ever owned had wide-open aperture until you hit the shutter release. And it's not only "pro" tools that had a button to check DOF; even my totally cheap Minolta X-9 had one (and a split-prism viewfinder, which I don't even have on the $1400 30D, which pisses me off to no end).

marlof

DanielB wrote:

modern lenses don't have apeture rings like the old manual cameras did

some do. The Panasonic/Leica combo seems to believe strongly in the old feel, as this lens (and the DMC-L1, and the DMC-LC1 before that) shows.

Nikolai

Well,

jimf wrote:

While admittedly my oldest SLR is only twenty six years old, every 35mm SLR I've ever owned had wide-open aperture until you hit the shutter release. And it's not only "pro" tools that had a button to check DOF; even my totally cheap Minolta X-9 had one (and a split-prism viewfinder, which I don't even have on the $1400 30D, which pisses me off to no end).

I was talking about somewhat older crowd, 50s..60s..
I agree, split-prizm is a very nice thing to have, I miss it a lot...:cry
Cheers!

pathfinder

A little history about SLRs, if my memory serves me:):

The earliest lenses were fixed apertures - they had aperture rings so that they could be opened for focusing, and then stopped down to the shooting aperture for shooting manually. This had to be done manually for each and every single exposure. Most of these cameras wer pre WWII if memeory serves.

Later, a spring loaded mechanism was incorporated to reopen the aperture after the exposure was taken - these were called pre-set lenses. The shooter only had to stop the lens down to the chosen aperture and a spring reopened the aperture ring after the shutter curtain completed its passage.

Finally, fully automatic aperture lenses were introduced which closed and then re-opened after the shutter was triggered. The earlier lenses had an external mechanical aperture ring. Canon abandoned external mechanical aperture rings for electrical control with the EOS series of lenses, which allowed more sophisiticated control of the aperture. Most of the mechanical aperture rings did not allow 1/3 stop increments like the the electrically controlled apertures do. Fully automatic apertures were routine by the mid 1950's or 1960s.

Automatic here refers only to setting the aperture. Autofocusing is a seperate feature entirely.

Nikolai

Nice lesson, Jim!

pathfinder wrote:

Fully automatic apertures were routine by the mid 1950's or 1960s.

Not in the USSR, they were not.
We only started getting them in late 70s - early 80s. Until that time everything was pretty much "fixed aperture"..

But, I guess, just as with focus, this is a whole different story

pathfinder

Thanks Nick.
I remember reading about Exacta and Practika cameras when I was in high school and college. Many of their lenses were pre-sets I belleve.

Pre-set lenses were still fairly common in the 1970's

I still own a Tamron 90mm macro Adpatall mount lens which is a pre-set style lens.

Pentax, Nikon, Olympus and Canon OEM lenses were almost all automatic aperture by the 1970s - this is all based entirely on my carbon-based memory chips in my head, so don't take it as gospel.:):

Nikolai

Hey, those were German..:-)

pathfinder wrote:

I remember reading about Exacta and Practika ...

Well, Eastern German, to be accurate, but still "foreign" for us(sr:-). Besides, during the infamous "cold war" anybody with a decent camera/optics in USSR was automatically considered "suspicious" and "potential spy". In fact, you could heasily get arrested for taking pictures of "federal" buildings (and since nearly every building was "federal", not many were left open, except for purely touristy places, like Moscow or St. Petersburg, aka Leningrad), factories, bridges, roads,... well, pretty much, everything :-)

All in all, for the first time in my life I saw a zoom lens camera was mid/late 80s. It was 35mm film P&S, but, man, I still remember how cool it was.
I was flying home from a 6+ white-water rafting trip in Pamir Mountains (I got badly injured and had to cut the trip short), and hooked up with another guy on the flight to Moscow. He was from Lithuania (or some other Baltic state, don't remember), he was into photography (as was I) and he was also injured in the mountains, so we had a lot to discuss:-). So he had this 3x zoom P&S... With built in meter, flash, and all other stuff. He told me he was getting photo awards a lot, since not many people could have such kind of equipment at the time:-)

Those were the days..

gtc

be careful daniel...
or you will start playing around with manual lenses and adapters like Ziggy and myself,and others and find that you can get some very good primes for not very much.

ok some may have some ca in really bright situations but other than that....the aperture ring,the solid smooth focus ring,the solid metal construction,some lenses with cemented elements,rare earth coatings,the sharp images...it becomes addictive but at a lower cost...now that I have worked out my favoured and most used focal lengths I can now invest in some L glass or Zeiss etc and be confident that I won't be trying to sell them within a few years