Lens Mount Question (Canon DSLR)

[iskoos]

Hi,

I plan on buying a Canon DSLR. I found out that 5D and Rebel series DSLR's use same lenses. In other words, they do have the same lens mount (what Canon calls "EF").
I definitely liked this because this way, I will be able to keep my lenses when I upgrade the body in the future.
But at the same time, I didn't understand it.:???:

Rebel series use APS-C size sensor and 5D uses full frame sensor.
How would they use same lenses? Doesn't the lens diameter change with the image size sensor?

I am hoping somebody will explain this to me?

Thanks

 

[Dao]

5D: EF mount lens only
Rebel: EF and EF-S mount lens

If you buy only EF lens, you can use the lens on any Canon EOS cameras including film based EOS cameras.

Quoted from Wikipidea:
"The "S" in EF-S stands for "short back focus", which means that the rear element of the lens is closer to the image sensor than on regular 35 mm SLR cameras."

 

[icassell]

Canon actually has 2 variants on the lens mount ... the EF and the EF-S. The EF-S lenses are only useable on the crop-sensor cameras, whereas the EF mount is useable on any EOS camera. If you are thinking of upgrading your camera to a Full Frame body, buy only EF mount or be prepared to sell your EF-S lenses.

 

[iskoos]

I see... It makes more sense right now.
The lense rebel series cameras come with is 18-55mm EF-S lense. This lense will NOT work on 5D because 5D only uses EF lenses...

Alright so far... But can someone also explain if EF lenses have larger diameter than EF-S lenses?

I am hoping you understand where I am coming from. I am trying to find out what determines the lens diameter...

 

[Dao]

I am trying to find out what determines the lens diameter...

why??

 

[iskoos]

I am trying to find out what determines the lens diameter...

why??

So when somebody askes me the same thing one day, I do not have to ask the question of "why??" and be able to explain them instead...

Do not get mad at me but I would like to learn things rather than memorizing them... When you truly learn what it is, you will never forget. If you memorize, you will forget it one day...

It is just how me works...

 

[Big Mike]

What, specifically, are you talking about when you say 'lens diameter'?
The front of the lens? The diameter of the body? The mount?

The mount is the same, but the actual size of the lens is determined by the design of the lens; the maximum aperture, the features (IS etc) and so on.

One thing that does change between EF and EF-S lenses, is the size of of the image circle at the film plane (sensor). Since EF-S lenses are made for cameras with a smaller sensor, their image circle doesn't need to as big as the one that EF lenses need to create.
This is why, if you did rig an EF-S lens to fit a fill frame camera, you would have a vignette on the corners.

 

[t00sl0w]

not to thread jack....but this may be relevant....

is there a adapter for a 4/3 35mm to the EF mount?

 

[Dao]

not to thread jack....but this may be relevant....

is there a adapter for a 4/3 35mm to the EF mount?

Canon EOS lens Adapters - Manual focus lenses on Canon EOS bodies

 

[JButler]

The lens diameter doesn't matter. What you care about is the size of the image that's projected on the camera's sensor. EF-S lenses project a small image in the sensor. Large enough to fill up an APS-C, but too small for a full frame sensor. If you shot an EF-S lens on a 5D your images would come out as little circles.

 

[iskoos]

The lens diameter doesn't matter. What you care about is the size of the image that's projected on the camera's sensor. EF-S lenses project a small image in the sensor. Large enough to fill up an APS-C, but too small for a full frame sensor. If you shot an EF-S lens on a 5D your images would come out as little circles.

Well, the lens diameter does matter. You confirm this in your paragraph above. If the lens diameter would not matter then, they would make the full frame cameras work with tiny lenses that we see on P&S cameras. Do you think this would be possible?
I am pretty sure we talk about the same thing but perhaps I couldn't explain myself well.

Big Mike, your last paragraph is I guess what I was asking about: image circle. EF-S lenses create smaller image circle for smaller image sensors and EF lenses create larger ones deu to the full frame sensor size.
When I was asking about lens diameter, I was asking in general but it looks like there is not one specific lens diameter we can talk about.

 

[Big Mike]

When I was asking about lens diameter, I was asking in general but it looks like there is not one specific lens diameter we can talk about.

There are probably hundreds of parts to a lens that have a diameter...you just needed to be more specific.

 

[Derrel]

not to thread jack....but this may be relevant....

is there a adapter for a 4/3 35mm to the EF mount?

Canon EOS lens Adapters - Manual focus lenses on Canon EOS bodies

YES, there is an adapter available to mount 35mm system lenses onto 4/3 bodies. The 4/3 system is a very adaptable system as far as using almost any lens. This adapter is $175 Adapters: Olympus E-1

There are a few others also; I beleive Olympus itself has made some adapters.

The USA company Fotodiox is an excellent source for adapters. eBay also has many adapters. Prices are all over the map on adapters.

 

[t00sl0w]

not to thread jack....but this may be relevant....

is there a adapter for a 4/3 35mm to the EF mount?

Canon EOS lens Adapters - Manual focus lenses on Canon EOS bodies

YES, there is an adapter available to mount 35mm system lenses onto 4/3 bodies. The 4/3 system is a very adaptable system as far as using almost any lens. This adapter is $175 Adapters: Olympus E-1

There are a few others also; I beleive Olympus itself has made some adapters.

The USA company Fotodiox is an excellent source for adapters. eBay also has many adapters. Prices are all over the map on adapters.

thanks, what about 4/3-EF?

 

[Derrel]

I do not believe there is any adapter that will allow the use of 4/3 or micro 4/3 mount lenses on Canon EF bodies; since the 4/3 sensor is 17.3mm x 13mm in size, I do not think that "most" 4/3 mount lenses would have a large enough image circle to cover an APS-C sensor. The other problem is that 4/3 lenses use electronic diaphragm control--there is no aperture ring on the lenses of 4/3 cameras, so it would be impossible to control the aperture of a 4/3 lens adapter to another system's body without an adapter that had sophisticated electronics. So, at this time, there are no 4/3 to Canon EF adapters...

But there are adapters, quite a few, that allow all sorts of SLR lenses to be used on both 4/3 and micro 4/3 cameras; that's become a sort of cult thing in Japan, using older vintage lenses on your micro 4/3 camera.