Camera optical lens

1. A camera optical lens comprising, from an object side to an image side in sequence: a first lens having a positive refractive power, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens;

wherein the camera optical lens satisfies following conditions:

0.95≤ f/TTL;

−3.50≤ f 2/ f≤− 1.80;

2.00≤ f 4/ f≤ 7.00; and

2.50≤( R 5+ R 6)/( R 5− R 6)≤20.00;

where

f denotes a focal length of the camera optical lens;

f2 denotes a focal length of the second lens;

f4 denotes a focal length of the fourth lens;

TTL denotes a total optical length from an object-side surface of the first lens to an image surface of the camera optical lens along an optical axis;

R5 denotes a central curvature radius of an object-side surface of the third lens; and

R6 denotes a central curvature radius of an image-side surface of the third lens.

2. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

0.26≤ f 1/ f≤ 0.81;

−2.69≤( R 1+ R 2)/( R 1− R 2)≤−0.86; and

0.06≤ d 1/ TTL≤ 0.19;

where

f1 denotes a focal length of the first lens;

R1 denotes a central curvature radius of the object-side surface of the first lens;

R2 denotes a central curvature radius of an image-side surface of the first lens; and

d1 denotes an on-axis thickness of the first lens.

3. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

1.60≤( R 3+ R 4)/( R 3− R 4)≤8.49; and

0.02≤ d 3/ TTL≤ 0.06;

where

R3 denotes a central curvature radius of an object-side surface of the second lens;

R4 denotes a central curvature radius of an image-side surface of the second lens; and

d3 denotes an on-axis thickness of the second lens.

4. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

−51.83≤ f 3/ f≤− 2.39; and

0.02≤ d 5/ TTL≤ 0.06;

where

f3 denotes a focal length of the third lens; and

d5 denotes an on-axis thickness of the third lens.

5. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

1.54≤( R 7+ R 8)/( R 7− R 8)≤12.30; and

0.03≤ d 7/ TTL≤ 0.10;

where

R7 denotes a central curvature radius of an object-side surface of the fourth lens;

R8 denotes a central curvature radius of an image-side surface of the fourth lens; and

d7 denotes an on-axis thickness of the fourth lens.

6. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

−2.28≤ f 5/ f≤− 0.61;

−0.50≤( R 9+ R 10)/( R 9− R 10)≤−0.11; and

0.03≤ d 9/ TTL≤ 0.14;

where

f5 denotes a focal length of the fifth lens;

R9 denotes a central curvature radius of an object-side surface of the fifth lens;

R10 denotes a central curvature radius of an image-side surface of the fifth lens; and

d9 denotes an on-axis thickness of the fifth lens.

7. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

−5.32≤ f 6/ f≤− 1.10;

1.31≤( R 11+ R 12)/( R 11− R 12)≤5.45; and

0.02≤ d 11/ TTL≤ 0.06;

where

f6 denotes a focal length of the sixth lens;

R11 denotes a central curvature radius of an object-side surface of the sixth lens;

R12 denotes a central curvature radius of an image-side surface of the sixth lens; and

d11 denotes an on-axis thickness of the sixth lens.

8. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

1.06≤ f 7/ f≤ 4.58;

1.04≤( R 13+ R 14)/( R 13− R 14)≤5.03; and

0.07≤ d 13/ TTL≤ 0.22;

where

f7 denotes a focal length of the seventh lens;

R13 denotes a central curvature radius of an object-side surface of the seventh lens;

R14 denotes a central curvature radius of an image-side surface of the seventh lens; and

d13 denotes an on-axis thickness of the seventh lens.

9. The camera optical lens according to claim 1 , wherein the camera optical lens further satisfies following conditions:

−8.35≤ f 8/ f≤− 1.40;

1.62≤( R 15+ R 16)/( R 15− R 16)≤10.76; and

0.04≤ d 15/ TTL≤ 0.18;

where

f8 denotes a focal length of the eighth lens;

R15 denotes a central curvature radius of an object-side surface of the eighth lens;

R16 denotes a central curvature radius of an image-side surface of the eighth lens; and

d15 denotes an on-axis thickness of the eighth lens.