Non-connected Aperture

[Snapitjack]

Sigma 50-500 & Canon 70D

Question; When the lens is removed from the camera, does the aperture stay where it was set by the camera, park in the most closed position or park in the most open position?

Is it also the same for all lenses made for Canon or does it depend on the lens manufacturer?

Thank you for any insight.

 

[The_Traveler]

Typically the aperture of the lens is wide open until the instant before exposure.
That's how you can see through the lens at its maximum aperture (brightness)

 

[astroNikon]

Typically the aperture of the lens is wide open until the instant before exposure.
That's how you can see through the lens at its maximum aperture (brightness)

Is that correct Lew?

Off my camera my aperture is f/22 or f/32 whatever is there on my Nikons
I don't know what it is when on the camera
but the aperture lever isn't being touched to open the aperture to f/1.8 / 2.8 etc

I checked a AF-D and G lens

 

[Derrel]

Typically the aperture of the lens is wide open until the instant before exposure.
That's how you can see through the lens at its maximum aperture (brightness)

Is that correct Lew?

Off my camera my aperture is f/22 or f/32 whatever is there on my Nikons
I don't know what it is when on the camera
but the aperture lever isn't being touched to open the aperture to f/1.8 / 2.8 etc

I checked a AF-D and G lens

Nikon and Canon are reversed when removed from the camera; Nikkor lenses close down to their smallest aperture when removed from the camera. Nikon lenses are HELD open by the camera, and the menchanical aperture actuator inside the camera "allows" the spring-loaded diaphragm to close down--it does not "make the lens close" by force, but instead allows it to close down. which is very different from other brands.

I thought the trick with Canon was to hold the depth of field preview in, and turn the Canon camera OFF, then remove the lens, and the lens would stay set to the aperture that had been set when the power was ON and the DOF preview was held in...this was one trick users of non-AF, non-CPU extension tubes were able to use in order to get some crude control over aperture. In normal use, Canon lenses open wide, to their maximum aperture value, when removed from the camera body.

 

[KmH]

Nikon SLR/DSLR cameras have a mechanical connection between the camera and the lens for the aperture.
The motor that controls the lens aperture is in the camera body.

When the lens is not mounted the aperture closes all the way. When remounted it opens up all the way.

Canon SLR/DSLR cameras made since 1987 (intro of EOS) do not use any mechanical connections between the camera and lens.
The motor that controls the lens aperture is in the lens.

 

[Gavjenks]

^
None of which answers the OP's question, which is about a Sigma lens, which has no guarantee of having the same defaults simply due to the fact of being offered in another company's mount.

FWIW, I do not know the answer for the lens mentioned in the OP, HOWEVER, I used to own a 10-20mm Sigma lens, in Canon mount. I know for a fact that when I hit the DOF preview button, and removed the Sigma 10-20, its aperture did in fact remain where it had been, and did not either open all the way or close all the way. I.e. it acted like a normal canon lens.

I would guess that the sigma 50-500 is similar. But cannot guarantee.

 

[Derrel]

^
None of which answers the OP's question, which is about a Sigma lens, which has no guarantee of having the same defaults simply due to the fact of being offered in another company's mount.

FWIW, I do not know the answer for the lens mentioned in the OP, HOWEVER, I used to own a 10-20mm Sigma lens, in Canon mount. I know for a fact that when I hit the DOF preview button, and removed the Sigma 10-20, its aperture did in fact remain where it had been, and did not either open all the way or close all the way. I.e. it acted like a normal canon lens.

I would guess that the sigma 50-500 is similar. But cannot guarantee.

Perhaps you ought to, carefully this time, RE-READ the OP, Gav. It contains more than one question. And maybe use a little common sense too...

 

[Gavjenks]

Uh, right back atcha Derrel. At no point does anybody's post in this thread answer either of his two questions

Q1: "When the [Sigma 50-500] is removed from the [70D], does the aperture stay where it was set by the camera, park in the most closed position or park in the most open position?" Nobody answered this for the Sigma lens that question #1 is about, and I only have one example from a different lens, not a general answer.

Q2: "Is it also the same for all lenses made for Canon or does it depend on the lens manufacturer [such as Sigma, Tamron, etc.]?" This is an even broader question that everybody is so far even further from answering. Nikon doesn't make lenses for Canon as far as I know and is irrelevant, and answering about lenses made BY Canon is only a first short step toward addressing this, and it's the part he probably already knew about if he's even asking this in the first place.



It's like asking "Do all animals with four limbs have spines?" and having somebody respond "Yes, birds have spines."
or "Is an eagle warm-blooded?" and having somebody respond "All mammals are warm blooded."

 

[D-B-J]

Uh, right back atcha Derrel. At no point does anybody's post in this thread answer either of his two questions

Q1: "When the [Sigma 50-500] is removed from the [70D], does the aperture stay where it was set by the camera, park in the most closed position or park in the most open position?" Nobody answered this for the Sigma lens that question #1 is about, and I only have one example from a different lens, not a general answer.

Q2: "Is it also the same for all lenses made for Canon or does it depend on the lens manufacturer [such as Sigma, Tamron, etc.]?" This is an even broader question that everybody is so far even further from answering. Nikon doesn't make lenses for Canon as far as I know and is irrelevant, and answering about lenses made BY Canon is only a first short step toward addressing this, and it's the part he probably already knew about if he's even asking this in the first place.



It's like asking "Do all animals with four limbs have spines?" and having somebody respond "Yes, birds have spines."
or "Is an eagle warm-blooded?" and having somebody respond "All mammals are warm blooded."

In being the devils advocate, one could argue that the OP was loosely referring to any lens, and your assumption that they meant their listed sigma was just that, an assumption made on your part. One could also argue that it is clearly implied (by way of listing the lens/camera before the posited question) to substitute the "sigma 50-500" in when the OP states "when the lens is removed."

However, both instances are merely a discussion of semantics, and do nothing other than try to incite a menial spat which benefits the OP in no way at all.


Best,
Jake

P.S. To the OP, when I remove any lens from my camera, the aperture closes down all the way, and when I put a lens on the camera, it opens up to its maximum aperture.

 

[Snapitjack]

Thanks for the feedback everyone. I have enough info now and will experiment, especially with the DOF button.

I'll post back when I figure it out, tell you why I needed to know and anything else I discover.

Thanks again

 

[KmH]

. . . At no point does anybody's post in this thread answer either of his two questions . . .

1. There is no guarantee that answers will be provided, and people who respond in a thread are not required to provide answers.

2. It's a discussion forum, and other posts also had questions pertaining to Nikon.

 

[minicoop1985]

It's not a Sigma, but my Tamron's wide open when the camera is off. Unfortunately, Derrel's trick doesn't seem to work anymore. At least not with a Tamron lens and a 7D. Power goes off, aperture opens, even with the stop-down button held down. I would imagine Sigma to be similar, seeing as the only way the camera and lens communicate is the same.

 

[Snapitjack]

So this seems to be the run down; Both my Sigma and my Canon lenses default to wide open when removed from the camera. If I close the aperture and hold the DOF button down while removing the lens the aperture remains closed until I put it back on the camera, at which time, whether the camera is on or not, it pops back open.

It took a flashlight to figure this all out.

The reason I needed to know was because I have a non-functioning 2X Teleconverter, meaning the electrical part of it is useless. But with the aperture defaulting to wide open and the ability to close it gives me enough control to do what I want. Of course the shutter speed and ISO etc, doesn't require electrical connections.

I still have light metering, as well So I just have to manual focus and all is good.

Thanks again for all the help. I'm sorry the seemingly simple question lead to such contention.

 

[robbins.photo]

You might want to check out KEH. They have a pretty impressive collecton of used teleconverters and you could probably replace yours fairly cheap.

Sent from my LG-LG730 using Tapatalk

 

[Gavjenks]

That is good to know it works with other sigma lenses, jack, thanks for reporting back.
It's useful not just for broken teleconverters and the like, but also for cheaper extension tubes that don't have electrical communication, so you can get the DOF you need for macro shots.
Makes sigma slightly more affordable and reliable (backup in case electronics don't work with something) for macro, and seemingly not so much for Tamron (@minicoop's comment)