# How to determine FOV for Sony A mount lenses on Sony NEX via the a mount adaptor?



## erotavlas

Basically I want to know if I buy a Sony A mount lens that says 14mm and I stick it on the Sony NEX using the A to E mount adaptor.  Will I get roughly the same field of view as I would on an Sony DSLR, or will the 14mm field of view turn into something different?  (would it become less than 14mm or greater than 14mm)   

I just find it confusing determining the field of view and especially when we also have lenses that work for full frame and APSC in which case you need to take into account crop factor.


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## Kolia

I don't think it'll make any differences.


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## minicoop1985

If my research is correct, both are APS-C sensors, so I would imagine they would be the same... but I could be wrong.


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## DiskoJoe

erotavlas said:


> Basically I want to know if I buy a Sony A mount lens that says 14mm and I stick it on the Sony NEX using the A to E mount adaptor.  Will I get roughly the same field of view as I would on an Sony DSLR, or will the 14mm field of view turn into something different?  (would it become less than 14mm or greater than 14mm)
> 
> I just find it confusing determining the field of view and especially when we also have lenses that work for full frame and APSC in which case you need to take into account crop factor.



So what you are saying is that you are confused by simple mulitplication? Whats 14 x 1.5? Go!!!


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## erotavlas

no thats not the issue, I understand the crop factor when you are using a lens designed for full frame (35mm) sensor.  I twas designed to cover that sensor and when you use a smaller APSC sensor the image gets cropped by that factor.  However in the case of NEX I'm not so sure this holds true any more because you are eliminating that bit of space needed for the mirror.  bringing the lens closer to the camera body.  

So for an e-mount lens I'm guessing that they are designed to cover the whole sensor area? In which there is no crop factor? Is that right?
but when I use the adaptor for the A mount lens on the NEX this brings the lens away from the sensor making it more like a DSLR in which you need to use the crop factor. Or do you?  Because some lenses are designed to cover only the APSC area but other are for full frame....blah blah blah and now you see that it gets more complicated and annoying


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## Kolia

50mm lens on any Sony APS-C DSLR should have the same FoV as that 50mm + adapter on a NEX body.

The lens would never be able to focus if the back spacing (for the mirror like you said) was not the same.


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## DiskoJoe

erotavlas said:


> no thats not the issue, I understand the crop factor when you are using a lens designed for full frame (35mm) sensor.  I twas designed to cover that sensor and when you use a smaller APSC sensor the image gets cropped by that factor.  However in the case of NEX I'm not so sure this holds true any more because you are eliminating that bit of space needed for the mirror.  bringing the lens closer to the camera body.
> 
> So for an e-mount lens I'm guessing that they are designed to cover the whole sensor area? In which there is no crop factor? Is that right?
> but when I use the adaptor for the A mount lens on the NEX this brings the lens away from the sensor making it more like a DSLR in which you need to use the crop factor. Or do you?  Because some lenses are designed to cover only the APSC area but other are for full frame....blah blah blah and now you see that it gets more complicated and annoying



The sizing is always based on 35mm equivalent. So if a lens says 24mm, its actually 36mm on a crop of 1.5. This is true for all systems.


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## KmH

DiskoJoe said:


> The sizing is always based on 35mm equivalent. So if a lens says 24mm, its actually 36mm on a crop of 1.5. This is true for all systems.


A 24 mm lens is actually 24 mm, even when mounted on a crop body camera.

Where a 1.5 crop factor is involved, the 24 mm lens delivers a field of view (FoV) that would be equivalent to the FoV a 38.4 mm lens would deliver that was mounted on a full frame (35 mm) camera.

Plus that is not true for all systems. It is only true for camera systems that have the same flange focal distance. Flange focal distance - Wikipedia, the free encyclopedia

When an adapter has to account for a flange focal distance difference between camera systems, it can only do so by having an optic in the adapter to settle the account.

The OP should contact Sony or use the Sony Web site chat feature.
The Sony web page for the adapter has little information, and DAMN! - $200 for that puppy. A-Mount to E-mount Mount Adaptor - Alpha DSLR Accessories Sony Store - Sony US
Sony sure isn't bashful about digging deep into it's customers wallets.


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## minicoop1985

If I'm correct, at least one of the adapters from A to E mount has a translucent mirror too-phase detection AF? Quite the system.

Here's one:

Sony LA-EA2 A NEX Camera Mount Adapter LA-EA2


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## DiskoJoe

KmH said:


> DiskoJoe said:
> 
> 
> 
> The sizing is always based on 35mm equivalent. So if a lens says 24mm, its actually 36mm on a crop of 1.5. This is true for all systems.
> 
> 
> 
> A 24 mm lens is actually 24 mm, even when mounted on a crop body camera.
> 
> Where a 1.5 crop factor is involved, the 24 mm lens delivers a field of view (FoV) that would be equivalent to the FoV a 38.4 mm lens would deliver that was mounted on a full frame (35 mm) camera.
> 
> Plus that is not true for all systems. It is only true for camera systems that have the same flange focal distance. Flange focal distance - Wikipedia, the free encyclopedia
> 
> When an adapter has to account for a flange focal distance difference between camera systems, it can only do so by having an optic in the adapter to settle the account.
> 
> The OP should contact Sony or use the Sony Web site chat feature.
> The Sony web page for the adapter has little information, and DAMN! - $200 for that puppy. A-Mount to E-mount Mount Adaptor - Alpha DSLR Accessories Sony Store - Sony US
> Sony sure isn't bashful about digging deep into it's customers wallets.
Click to expand...


Theyre still not as bad as apple. I remember when I worked with a girl that shot Nikon and edited on mac. She didnt know how to convert my sony files and I looked up to see that you need aperture which I think costs like $80 but is free for PC.


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## erotavlas

KmH said:


> DiskoJoe said:
> 
> 
> 
> The sizing is always based on 35mm equivalent. So if a lens says 24mm, its actually 36mm on a crop of 1.5. This is true for all systems.
> 
> 
> 
> A 24 mm lens is actually 24 mm, even when mounted on a crop body camera.
> 
> Where a 1.5 crop factor is involved, the 24 mm lens delivers a field of view (FoV) that would be equivalent to the FoV a 38.4 mm lens would deliver that was mounted on a full frame (35 mm) camera.
> 
> Plus that is not true for all systems. It is only true for camera systems that have the same flange focal distance. Flange focal distance - Wikipedia, the free encyclopedia
> 
> When an adapter has to account for a flange focal distance difference between camera systems, it can only do so by having an optic in the adapter to settle the account.
> 
> The OP should contact Sony or use the Sony Web site chat feature.
> The Sony web page for the adapter has little information, and DAMN! - $200 for that puppy. A-Mount to E-mount Mount Adaptor - Alpha DSLR Accessories Sony Store - Sony US
> Sony sure isn't bashful about digging deep into it's customers wallets.
Click to expand...


you know what would be easier? If they just stated the FOV right off the bat. Forget all this focal length crap. I mean its just confusing. I don't have the means to translate some mm value to what I think the FOV is when I'm shopping for a lens. 
How hard is it ....65 degrees FOV on this sensor!!! and 83 degrees on this sensor!!! Wow that would be so much simpler And it would give me a way better picture in my head as to how wide or narrow the field of view of my image would be. 

GRRRR.....I feel like crushing my lens right now. :madmad:


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## Kolia

Buy a zoom lens if you are worried of getting an exact equivalent FoV !


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## Crabwok

Thank you OP for posting this question. I've had the same question since the A7 was announced. Metabones Smart Adaptor III doesn't seem (though I haven't had the opportunity to put my hands on one) to have any optics built in to compensate for the increase in flange distance. Yet I've seen multiple reviews using that exact adaptor with glass from Canon, Leica, Nikon etc... So what is the FoV, say, on a EF 50mm? Is it still 47*


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## AlejandroRivera

Here is giveaway from aputure, they will release macro tube set for sony NEX camera. If i can guess the right color, i can get free set.
https://www.facebook.com/Aputure/posts/686395864754909
Anyone know the color?


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## Scatterbrained

There is no need for optics when going from an SLR to a mirrorless system.  None at all.  All the adapter is doing is correcting registry distance.  Optics are needed when the registry distance of the camera is longer than the registry distance the lens was designed for, but not if it's shorter.   As far as the crop factor, it's just as it would be were you using an APS-C SLR.  No different.


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## AlejandroRivera

wow... i see, thanks for your opinion.


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