Ednsb Loc: Santa Barbara

I’ve got a few ef-s lens in my move from T4i to RP like the 10-18. If I put my EF 24mm on the T4i it had a multiplier of 1.6 so it was the equivalent of a 38.4mm. I’m not quite sure what happens with ef-s lens on the RP with adapter. I’ve been told it is now 1.6 times the EF-S or 16-28.8.

Please stay on question rather than tell me to buy some other lens. I have a ton of FF lens.

CHG_CANON Loc: the Windy City

The lenses work fine, including the feature that the mirrorless EOS RP will dynamically crop the image by the 1.6 crop factor to address the smaller image circle created by the EF-S mount lens. The impact is you've reduced your glorious 26MP full frame mirrorless camera to a 10MP body, producing images with less pixel resolution than your 18MP EOS T4i.

petrochemist Loc: UK

It's still a 10-18, the only way you can change that is by adding or taking away lens elements.

If it fits the adapter it won't cover the FF sensor giving you black round the outside.
Some crop lenses will give a circular image when used on a big enough sensor, most have baffles that restrict the light to nearer the intended format.

The 16-28.8 you refer to it the focal length range you'd need on the RF to match the field of view you are used to seeing on EF-S.

I've used a crop lens on my Sony A7ii as their NEX range lenses use the same mount. If used FF I get a black box with the image inside roughly equivalent to a 1.4x crop (slightly wider than the NEX sensor).
My MFT fisheyes give a nearly circular image adapted to FF, only restricted by the view of the very minimal hood.

CHG_CANON Loc: the Windy City

Again: The mirrorless EOS RP will dynamically crop the image by the 1.6 crop factor to address the smaller image circle created by the EF-S mount lens. The EOS system is all electronic and the Canon lens, Canon lens adapter, and Canon body all 'talk' to each other. No vignette around the image.

Ednsb Loc: Santa Barbara

Thanks CHG.

petrochemist Loc: UK

So it doesn't have the option to shoot FF despite the lens as both Sony & Nikon cameras do??
Strikes me as a minor but definitly negative thing.
A few of the crop lenses I have in other mounts manage to cover FF if pushed.

CHG_CANON Loc: the Windy City

If you're determined, one can check the manual to see of you can turn off the cropping function for EF-S lenses that place an even smaller circle than the 1.5 crop factor of Nikon and Sony.

Bbarn Loc: Ohio

Can't turn the automatic EF-S lens crop off on the RP. I think the same is also true for DX lenses on the FF Nikon Z series. Not sure about other brands.

bleirer

The RP automatically converts to the crop mode when it encounters an efs lens. As mentioned it can only record a max of 10.1 megapixels. I suppose it's possible there is some hack involving taping over contacts to fool the camera into thinking it has an unknown lens, but I don't know of one, nor would I try it. The OP says they have plenty of full frame lenses, so it might be best to sell the efs lenses.

petrochemist Loc: UK

As mentioned already I have personally used a native crop lens on Sony's FF & gained extra FOV (the menu has options for autocrop, no crop or always crop). Adapted lenses of course don't comunicate with the body so it never knows the intended sensor size for autocropping so there is hope even for those with crippled bodies, provided they're willing to focus manually.

I know of others who've done the same with other brands I think both Nikon & Pentax. It's easy enough to crop in post so it strikes me as a needless restriction to force the crop. When he K1 first came out there were many reports of DA series 'crop' lenses found to cover FF by those who tried them without auto crop.
It's only more recently I've investigated some of the options with Penatx crop lenses, both my 10-17 fisheye & my 10-24 UWA cover FF from if zoomed in to at least 14mm (where they give very close to the intended crop FOV) More usefully my DA55-300 covers FF at all focal lengths when adapted to Sony. Which means I can safely sell of the older film era F100-300 lens I have which is no faster, has a shorter range & weighs considerably more... :)

CHG_CANON Loc: the Windy City

Canon likely has a corporate email address, you should consider forwarding your product improvement ideas.

petrochemist Loc: UK

Why bother?
I've not liked the ergonomics of the bodies I've played with and while I do have a couple of Canon lenses they are in poor condition & about as far as possible from their best models. So I'm not likely to buy anything from them. The lenses I have were included free with a bundle that had a far more interesting lens.

stevefrankel

I don't think this is correct. I think you have lifted the central portion of your image -- with the same pixels and density -- to a smaller, more convenient package that would have been the same 10 megs of pixels than it was in the central portion of the image. Is my reasoning flawed?

DeanS Loc: Capital City area of North Carolina

The RP and R5 will auto covert to the crop factor for Canon lens only. For non-Canon lens, you have to go to the menu to covert.

bleirer

Whomever you were replying to, I'd say you are partially correct if you just took one shot with the full sensor and another in exactly the same position and focal length with the cropped sensor, except in practice you would have moved closer to fill the frame of the full sensor or used the zoom to zoom in to fill the frame, so you get more pixels on any given area of the subject.