Aperture setting on lens.........No more?


Feb 15, 2013
359
1
18
Singapore
#1
Morning,

This was raised partially in another forum much earlier.

I did not know in the current M4/3 zoom lens, the aperture control was in the body.
Even when you set the aperture priority mode to the largest opening, when you zoom to the max, the body electronic will adjust to a smaller opening to compensate in order to have a "perfect" picture.
I thought this applied for M4/3 system only.

Last week in ICT, have a small chat with a fellow reservist. He told me he was a wedding photographer using Nikon D800 with zoom lens instead of a fix lens.

I asked him whether the (Nikon)zoom lens aperture could be fix at a particular opening even when he zoomed the lens to the max. He gave me a blank look. He told me that he never pay attention to that or set the aperture opening in the lens before.

For those who have continusously taking photo with interchangeable lens from film era to today digital. Is it thru now a days, the lenses have no aperture settings?

Sometimes I feel like Rip Van Winkle wakes up from a long sleep.

Thank You
EisMann
 

Turbonetics

Senior Member
Feb 19, 2009
2,701
6
38
#2
Morning,

This was raised partially in another forum much earlier.

I did not know in the current M4/3 zoom lens, the aperture control was in the body.
Even when you set the aperture priority mode to the largest opening, when you zoom to the max, the body electronic will adjust to a smaller opening to compensate in order to have a "perfect" picture.
I thought this applied for M4/3 system only.

Last week in ICT, have a small chat with a fellow reservist. He told me he was a wedding photographer using Nikon D800 with zoom lens instead of a fix lens.

I asked him whether the (Nikon)zoom lens aperture could be fix at a particular opening even when he zoomed the lens to the max. He gave me a blank look. He told me that he never pay attention to that or set the aperture opening in the lens before.

For those who have continusously taking photo with interchangeable lens from film era to today digital. Is it thru now a days, the lenses have no aperture settings?

Sometimes I feel like Rip Van Winkle wakes up from a long sleep.

Thank You
EisMann
I may not be experience enough to answer your question but i don't really understand what u mean?
what lens did u use? does the zoom lens has constant fixed aperture or variable aperture throughout the zoom range?
when i use my zoom lenses,they can be fixed at the same aperture even when i zoom in and out because they are constant fixed aperture. if the zoom lens has variable aperture,then usually when u zoom in the aperture will stop down.
not sure is it what u mean?
 

Octarine

Moderator
Staff member
Jan 3, 2008
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Pasir Ris
#3
Nearly all modern lenses are controlled by the body. Whenever you dial the aperture setting using a knob or wheel on the body then obviously it's managed by the body. Exceptions are some Nikon lenses where the aperture can be controlled either by body or aperture ring on the lens. But even these lenses work similar to the fully automatic lenses: you turn the aperture ring to the target setting but the aperture remains wide open for focusing. Only upon pressing the shutter the body will flip a lever that closes the lens aperture to the preset value and opens it again after the picture is taken.
Other examples are (older) fully manual lenses from film era which either work with the same mechanical level or without - here one needs to close the aperture manually after focusing. Quite tedious but works for landscape and other forms of still life photography.
I do not understand your concerns, though. It is essential for the phase detection AF systems to have the widest possible aperture available to lock focus. Do read up about the phase detection AF and it should become clearer. Alternatively, if you have the chance, get a body and manual lens and try to focus at maximum aperture and at f/8.

Another point you mentioned is the closing of aperture when zooming. That's normal. Do remember: aperture is a ratio between focal length of the lens and diameter of physical opening. (More to read up: http://en.wikipedia.org/wiki/Aperture ) So it's obvious: if focal length is changed during zooming then something has to happen to the opening in order to keep the aperture value constant. Zoom lenses have an automatic aperture adjustment that works while zooming. Old lenses have it as well as recent ones. This adjustment is done inside the lens, not affected or controlled by the body. Aperture is a characteristic of the lens, nothing that the camera body can influence.
This aperture adjustment (or compensation) is necessary for exposure. The camera expects a certain amount if light based on wide open metering and the preset aperture. It is a predictive exposure calculation. If the amount is wrong due to missing aperture compensation then the exposure is off.
 

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keithwee

Moderator
Staff member
Aug 20, 2010
7,994
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LittleRedDot
#4
Hmm , I don't really understand but even for MFT , when I shoot in Manual and use a lens that has an aperture ring , (the 42.5/1.2 or the 15/1.7) , it does stay at that set aperture size during shooting.

For zoom lenses , I believe this is the same for either modern or vintage lenses since as I change the focal length the aperture size on the lens should change to compensate too. (That's why we have things like 40-150/f4-f5.6 right ?)

Imagine if I used a 14-150/f3-f5.6 and it allows me to fix at f3.5 at 150mm ; no one will pay for constant aperture zoom lenses anymore
 

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Edwin Francis

Senior Member
Mar 24, 2006
883
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www.sgwriter.com
#5
Mr Van Winkle, I think you've been asleep longer than you know! IIRC, there hasn't been any m4/3 lens with an aperture ring (there was a Panasonic 4/3 lens with an aperture ring years ago, but it didn't catch on)


Regarding your statement below -- the body does not change your aperture setting to make a 'perfect' picture. I think what's happening it that you are using a normal (ie. not constant max aperture) lens. For eg, if you set an Olympus 14-42/3.5-5.6 to f3.5 at 14mm focal length, and then zoom out to 42mm, the aperture reading changes to 5.6. That is simply because the max aperture a 42mm IS 5.6. This is the same with all the systems, not a feature or fault of the m4/3 system.

Even when you set the aperture priority mode to the largest opening, when you zoom to the max, the body electronic will adjust to a smaller opening to compensate in order to have a "perfect" picture.
I thought this applied for M4/3 system only.
 

daredevil123

Moderator
Staff member
Oct 25, 2005
21,657
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lil red dot
#6
There is one exception. When using a macro lens, and using Aperture priority mode, when you focus close, on some camera systems it will show the aperture value smaller than previously selected. The physical aperture stays the same, just that due to close focusing, you lose some light, and the camera automatically adjusts the aperture value to match the equivalent amount of light coming in. This happens in some systems (eg, Nikon). But on Canon, they do not do this adjustment.
 

BBTM

Senior Member
Nov 23, 2004
2,209
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BB West
#7
If the lens is not having a constant F stop, it will use a smaller F at tele. Therefore, I suspect that the nikon guy might be using a high end lens and so, F stop stays even he zoom in. But for kit lens, the F stop with change unless prime.
 

edutilos-

Senior Member
Dec 28, 2010
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#8
The changing of the aperture has nothing to do with compensation for a more perfect picture. It is the lens limitation. More expensive zoom lenses will tend to have constant maximum aperture throughout the range, less expensive zoom lenses (i.e. consumer grade) tend to have a smaller maximum aperture when longer focal lengths are used. For example, there is a 12-40mm f/2.8 constant aperture zoom lens for M4/3, this is "pro-grade" compared to say, 14-42 f/3.5-5.6 (standard kit zoom).

I do not know the full details of the conversation with your friend and you seem to have a limited understanding of photography equipment, but taking what you describe at face value, if he does not pay attention to the aperture used, I would have doubts on his capabilities and skill level as a wedding photographer. It is important as it will affect other parameters used especially the shutter speed and of course the output result of the picture - since it affects depth of field (i.e. how much of the photograph is in focus).


Most lenses will have aperture settings. An exception I can think of is mirror lens, which has fixed aperture. This is not the same as constant maximum aperture zoom lens. What has changed from film era to digital is that the aperture set is controlled in-camera body, rather than on the lens as an aperture ring as what was done previously for film era.

Hope this helps.
 

edutilos-

Senior Member
Dec 28, 2010
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#9
If the lens is not having a constant F stop, it will use a smaller F at tele. Therefore, I suspect that the nikon guy might be using a high end lens and so, F stop stays even he zoom in. But for kit lens, the F stop with change unless prime.
Prime lenses has fixed focal length so the term "constant maximum aperture" is not applicable to prime lenses.
 

Feb 15, 2013
359
1
18
Singapore
#10
Octarine,

Thanks for pointing out the wikipedia page.

That, was the Aperture(ring) I was referring to
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Feb 15, 2013
359
1
18
Singapore
#11
The whole thing started when I was pondering on the M4/3 telezoom lens from Olympus & Panasonic.
For the latter, it has an range of F/4.0-5.6 opening. Does it made a better buy?

I was explained in the M4/3 forum, for those have used before, the F4.0 could not maintain at the maximum zoom ie at 300mm.
2 days ago I was in Funan SLR to take a look at the lenses on displayed. He told me that other than Pentax and Nikon? The rest of the brands' lenses, the aperture opening will change accordingly when zoomed out to the max.

He told me for the Pana type, when zoomed to 300mm, the aperture changed to F5.6, still "better" than the Olympus at F6.7.

Thank You
EisMann
 

thoongeng

Senior Member
Jan 26, 2010
1,260
19
38
#12
The 'aperture ring' you showed are present in most older lenses where the aperture have to be controlled manually. Recent Nikon lenses (the 'G' type lenses) have also done away with it.

The f-number increasing or stays constant on zooming depends on the construction (and this is a different matter from whether the aperture ring is present or not) - as many have pointed out above, usually the higher grade lenses have constant aperture number while the consumer grade lenses do not have a constant aperture number. For example the Panasonic 35-100 f2.8 has a constant maximum aperture of f2.8 throughout the zoom range. Unfortunately both Olympus and Panasonic have not released any super-telezooms with constant aperture (these are usually very large sized eg look at Canon/Nikon 200-400 f4 lenses)

If you take a look at your example image, it's a Nikkor 35-135mm, f3.5-4.5 lens. Though the aperture ring stays at f3.5, when you zoom in the maximum f-number is actually f4.5, just that it is not physically stated on the aperture ring.

And when comparing the Panasonic 100-300 f4-5.6 and Olympus 75-300 f4.8-6.7, you can see the Panasonic has a bigger f-number at both ends of the zoom range, which lets more light in, but the penalty is that it is thicker and heavier.
 

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Feb 26, 2014
130
1
18
Singapore
#13
He told me that other than Pentax and Nikon? The rest of the brands' lenses, the aperture opening will change accordingly when zoomed out to the max.
Hi i think that salesman is totally wrong and saw you are an easy sucker and was trying to get you to buy a new system when you dont need it
 

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