Folded cameras with continuously adaptive zoom factor

1. A camera, comprising:

an optical path folding element (OPFE) for a folding a first optical path OP1 to second optical path OP2;

a lens including a plurality of lens elements divided into four lens groups arranged along a lens optical axis and marked, in order from an object side of the lens to an image side of the lens, G1, G2, G3 and G4; and

an image sensor,

wherein the camera is a folded Tele camera,

wherein the lens elements of a lens group do not move with respect to each other,

wherein G1 and G3 do not move with respect to each other,

wherein G2 and G4 do not move with respect to each other,

wherein the Tele camera is configured to change a zoom factor (ZF) continuously between a minimal zoom factor marked ZF MIN corresponding to a minimal effective focal length marked EFL MIN and a maximal zoom factor marked ZF MAX corresponding to a maximal effective focal length marked EFL MAX by moving G1 and G3 together relative to the image sensor and by moving G2 and G4 together relative to the image sensor,

wherein ZF MAX /ZF MIN ≥1.5,

wherein the camera is included in a camera module having a module height H M ,

wherein the lens has a lens aperture height H A ,

wherein both H M and H A are measured along an axis parallel to OP1, and

wherein H M <H A +3 mm.

2. The camera of claim 1 , wherein H M <H A +2 mm.

3. The camera of claim 1 , wherein 5 mm<H M <15 mm, and wherein 3 mm<H A <10 mm.

4. The camera of claim 1 , wherein the camera has an aperture diameter DA MIN at EFL MIN and a minimal F number F/# MIN =EFL MIN /DA MIN , and wherein F/# MIN <4.

5. The camera of claim 4 , wherein F/# MIN <3.

6. The camera of claim 4 , wherein F/# MIN <2.5.

7. The camera of claim 1 , wherein the camera has an aperture diameter DA MAX at EFL MAX , and a maximal F number F/# MAX =EFL MAX /DA MAX , and wherein 4.4<F/# MAX <6.

8. The camera of claim 1 , wherein the lens has a maximal total track length TTL MAX , and wherein the ratio TTL MAX /EFL MAX <1.2.

9. The camera of claim 1 , wherein a sequence of lens powers of lens groups G1, G2, G3 and G4 is positive-negative-positive-positive.

10. The camera of claim 1 , wherein the plurality of lens elements includes 10 lens elements.

11. The camera of claim 1 , wherein the camera has an aperture diameter DA MIN at EFL MIN and an aperture diameter DA MAX at EFL MAX , and wherein DA MIN /DA MAX >0.4.

12. The camera of claim 11 , wherein DA MIN /DA MAX >0.75.

13. The camera of claim 1 , wherein the camera has an aperture diameter DA MAX at EFL MAX , wherein 24 mm<EFL MAX <30 mm, and wherein 5 mm<DA MAX <7 mm.

14. The camera of claim 1 , wherein the OPFE is a prism, wherein the prism is a cut prism with a prism optical height H P measured along an axis parallel to OP1 and with a prism optical width W P measured along an axis perpendicular to both OP1 and OP2, and wherein W P is larger than H P by between 5% and 30%.

15. The camera of claim 1 , wherein the camera has an aperture diameter DA MIN at EFL MIN and a minimal F number F/# MIN =EFL MIN /DA MIN , wherein the camera has an aperture diameter DA MAX at EFL MAX , and a maximal F number F/# MAX =EFL MAX /DA MAX , and wherein F/# MAX /F/# MIN <1.3-3.

16. The camera of claim 1 , wherein ZF MAX /ZF MIN ≥1.75.

17. The camera of claim 1 , wherein ZF MAX /ZF MIN ≥2.

18. The camera of claim 1 , wherein EFL MIN ≥9 mm.

19. The camera of claim 18 , wherein 24 mm<EFL MAX <30 mm.

20. The camera of claim 1 , wherein the folded Tele camera is included in a dual-camera along with a Wide camera having a field-of-view larger than the folded Tele camera.

21. A mobile device comprising the camera of claim 1 .

22. The mobile device of claim 21 , wherein the mobile device is a smartphone.

23. A mobile device comprising the camera of claim 20 .

24. The mobile device of claim 23 , wherein the mobile device is a smartphone.