Am I limited to EF-S?

soldier5637

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May 7, 2013
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Hey there, I'm new to the world of photography but RAPIDLY delving right into it all. I just got my SL1 (For a 12 pack of beer I might add) and a STM IS 18-55 kit lens. This is a fine lens for lots of things but I find myself aching to shoot astro photography. I have tried and gotten alright results with this lens, but my question is this: Can I use the EF 50mm lens on my SL1 with an APS-C sensor? Well I know it will fit, but will it not crop the image so something like an 80mm lens? I've read very confusing comments, some making it seem so and some not.
 

overclockingrocks

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Oct 9, 2006
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Yes you can use EF lenses on an APS-C sensor camera with no issues. APSC just magnifies things by a factor of 1.6x vs a full frame 35mm equivalent sensor. IE a 50mm lens on APS-C is the same view as 85mm on a full frame. that's why people use 50mm lenses on APS-C for portrait work.

So short answer yes it will work and yes it will crop the image. If you want the 50mm equivalent FOV a ~30mm lens with the 1.6x crop factor would be your best bet. There is a 24mm pancake which would do well. I own a 50D so it's the same size sensor and I use a 50mm for potraits. Works well. stop down a bit to around 2.8~4 and you'll get nice subject separation and great sharpness. another great hint is set your flash to +1 bounce it off the ceiling and work at F5.6 with an iso of 500 produces amazing images

 
You can use all EF and EF-S lenses on the SL1, though longer EF lenses may feel sluggish due to lower motor driving power. EF and EF-S lenses use the same focal length assumptions, so a 50mm EF will look the same as a 50mm EF-S. Any sensor based cropping (not really cropping, rather smaller capture area) will be the same regardless of if it's EF or EF-S.

As for astrophotography, the SL1 isn't exactly the best camera to use, but the 50mm f1.8 lens when stopped down to 2.8 or smaller will be able to get you very good results. Just remember that focusing on that lens will be difficult, especially with the SL1's viewfinder and lack of distance information on the lens.
 

soldier5637

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May 7, 2013
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A-ha. See. This is what I was talking about. One says the image will he cropped, one does not. This is like all the other forums I checked. While I appreciate both answers, this leaves me not really knowing what to do. I don't want to get a 50mm lens if it's going to act like a 80mm, that's incredibly narrow for astrophotography.
 


No, the lens image will never be cropped, it's that the projection area captured that happens to be "cropped" due to a smaller sensor (less of the projection captured). The lens image is only cropped when using a EF-S lens on a full frame sensor (image circle is smaller than what a lens should produce, so image gets "cropped" and half your frame is black). If you have a 50mm EF lens, it will provide the exact same effective field of view as a 50mm EF-S one on APS-C.

What you are discussing is effective field of view, in which case yes, a 50mm lens on APS-C will look like a 80mm lens on a 36mm full frame sensor. If you want an effective field of view similar to 50mm on full frame, consider the new 35mm lenses (2.8 and faster), since they will provide roughly 45mm equivalent field of view.