Fixed Focal Length CHDK Scripts

Copyright (c) 2025, Jose R Garcia ([email protected]).
All rights reserved.

META	DATA
Project	Fixed Focal Length CHDK Scripts
Version	v1.0
Lincense	GNU GPLv3
Prepared by	Jose R Garcia ([email protected])
Status	Released

Scope

This document covers the development of the scripts and usage of the scripts libaray in the /SCRIPTS directory. These scripts are used to allow users of CHDK with particular cameras to select specific focal lengths.

Table of Contents

• Fixed Focal Length CHDK Scripts
  • Scope
  • Table of Contents
  • Develpment
    • Scripts Library
  • Target Cameras(...so far)
    • PowerShot SX110 IS
      • Camera Specs
      • Zoom Steps to Focal Length Equivalency Relation
  • ELPH 190 IS / IXUS 180 IS
    • Camera Specs
    • Zoom Steps to Focal Length Equivalency Relation

Develpment

This project provides a generic script that logs the steps and its respective focal length. This script is a tool that anyone using CHDK could use to quire this information. There are also bespoken fixed focal legth script for each target camera. These scripts were created from the zoom steps logs gathered by the aforementioned tool. All the scripts can be found in the /SCRIPTS directory.

Scripts Library

Script name	Description
FocalSteps.lua	Loops over the available zoom steps and logs the Full Frame equivalent focal length in a markdown syntax table. The generated log file is named LOG_0001.TXT and written to the /LOGS directory of the camera's CHDK folder.
FixedLensSX110.lua	This script starts by displaying the available selection of focal lengths; after which it displays an input text box that accepts one character to provide the user the capability to select between 15 different focal lengths . The focal legth selection is specific to the PowerShot SX110 IS, although it is probably the same for the PowerShot SX120 IS due to the likeness of these cameras.
FixedLens_elph190_ixus180.lua	This script starts by displaying the available selection of focal lengths; after which it displays an input text box that accepts one character to provide the user the capability to select between 15 different focal lengths . The focal legth selection is specific to the PowerShot ELPH 190 IS / IXUS 180 IS.

Target Cameras(...so far)

PowerShot SX110 IS

Camera Specs

Attribute	Value
Sensor Size	1/2.5" Sensor
Sendor Resolution	10MP
Display	3" Fixed Screen
ISO Range	80 - 1600
Image Stabilization	Optical
Video Resolution	640 x 480
Equivalent Focal Lens	36-360mm
Aperture	F2.8-4.3
Weight	285g
Dimensions	111 x 71 x 45mm

Zoom Steps to Focal Length Equivalency Relation

Step	1/2.5"	FF	Name	Category	Option
0	6.00 mm	36 mm	Street	Wide	A
1	6.67 mm	40 mm	-	Wide	-
2	7.17 mm	43 mm	Eye	Normal	B
3	8.17 mm	49 mm	Nifty	Normal	C
4	9.00 mm	54 mm	-	Normal	-
5	10.17 mm	61 mm	Narrow	Normal	D
6	11.50 mm	69 mm	Portrait70	Noral	E
7	12.67 mm	76 mm	Portrait75	Medium Tele	F
8	14.33 mm	86 mm	Portrait85	Medium Tele	G
9	16.00 mm	96 mm	Portrait96	Medium Tele	H
10	18.00 mm	108 mm	Portrait110	Medium Tele	-
11	20.00 mm	120 mm	-	Tele	-
12	22.33 mm	134 mm	Sports135	Tele	I
13	25.16 mm	151 mm	Sports155	Tele	J
14	28.00 mm	168 mm	-	Tele	-
15	31.50 mm	189 mm	-	Tele	-
16	34.83 mm	209 mm	Sports210	Tele	K
17	38.83 mm	233 mm	-	Tele	-
18	42.50 mm	255 mm	Sports255	Tele	L
19	46.50 mm	279 mm	Sports280	Tele	M
20	50.83 mm	305 mm	Nature300	Super Tele	N
21	55.83 mm	335 mm	-	Super Tele	-
22	60.00 mm	360 mm	Nature360	Super Tele	O

ELPH 190 IS / IXUS 180 IS

Camera Specs

Attribute	Value
Sensor Size	1/2.3" Sensor
Sendor Resolution	20MP
Display	2.7" Fixed Screen
ISO Range	100 - 1600
Image Stabilization	Optical
Video Resolution	1280 x 720
Equivalent Focal Lens	24-240mm
Aperture	F3.0-6.9
Weight	138g
Dimensions	95 x 57 x 24mm

Zoom Steps to Focal Length Equivalency Relation

Step	1/2.3"	FF	Name	Category	Option
0	4.300 mm	23.888 mm	Architect	Ultra Wide	A
1	4.465 mm	24.805 mm	-	Ultra Wide	-
2	4.509 mm	25.050 mm	-	Ultra Wide	-
3	4.556 mm	25.311 mm	-	Ultra Wide	-
4	4.605 mm	25.583 mm	-	Ultra Wide	-
5	4.656 mm	25.866 mm	-	Ultra Wide	-
6	4.709 mm	26.161 mm	-	Ultra Wide	-
7	4.766 mm	26.477 mm	-	Ultra Wide	-
8	4.826 mm	26.811 mm	-	Ultra Wide	-
9	4.889 mm	27.161 mm	-	Ultra Wide	-
10	4.956 mm	27.533 mm	-	Ultra Wide	-
11	5.026 mm	27.922 mm	Street28	Wide	B
12	5.101 mm	28.338 mm	-	Wide	-
13	5.180 mm	28.777 mm	-	Wide	-
14	5.263 mm	29.238 mm	-	Wide	-
15	5.350 mm	29.722 mm	-	Wide	-
16	5.443 mm	30.238 mm	-	Wide	-
17	5.443 mm	30.238 mm	-	Wide	-
18	5.643 mm	31.350 mm	-	Wide	-
19	5.751 mm	31.950 mm	-	Wide	-
20	5.865 mm	32.583 mm	-	Wide	-
21	5.865 mm	32.583 mm	-	Wide	-
22	6.111 mm	33.950 mm	-	Wide	-
23	6.243 mm	34.683 mm	-	Wide	-
24	6.243 mm	34.683 mm	Street35	Wide	C
25	6.527 mm	36.261 mm	-	Wide	-
26	6.527 mm	36.261 mm	-	Wide	-
27	6.839 mm	37.994 mm	-	Wide	-
28	7.006 mm	38.922 mm	-	Wide	-
29	7.181 mm	39.894 mm	-	Wide	-
30	7.181 mm	39.894 mm	-	Wide	-
31	7.554 mm	41.966 mm	-	Normal	-
32	7.753 mm	43.072 mm	Eye	Normal	D
33	7.960 mm	44.222 mm	-	Normal	-
34	7.960 mm	44.222 mm	-	Normal	-
35	8.176 mm	45.422 mm	-	Normal	-
36	8.635 mm	47.972 mm	-	Normal	-
37	8.878 mm	49.322 mm	-	Normal	-
38	8.878 mm	49.322 mm	Nifty	Normal	E
39	9.390 mm	52.166 mm	-	Normal	-
40	9.661 mm	53.672 mm	-	Normal	-
41	9.940 mm	55.222 mm	-	Normal	-
42	9.940 mm	55.222 mm	-	Normal	-
43	10.527 mm	58.483 mm	-	Normal	-
44	10.527 mm	58.483 mm	-	Normal	-
45	10.835 mm	60.194 mm	-	Normal	-
46	11.477 mm	63.761 mm	-	Normal	-
47	11.477 mm	63.761 mm	Narrow	Normal	F
48	11.811 mm	65.616 mm	-	Normal	-
49	12.506 mm	69.477 mm	Portrait70	Medium Tele	G
50	12.866 mm	71.477 mm	-	Medium Tele	-
51	13.234 mm	73.522 mm	Portrait75	Medium Tele	H
52	13.610 mm	75.611 mm	-	Medium Tele	-
53	13.994 mm	77.744 mm	-	Medium Tele	-
54	14.385 mm	79.916 mm	-	Medium Tele	-
55	14.784 mm	82.133 mm	-	Medium Tele	-
56	15.190 mm	84.388 mm	Portrait85	Medium Tele	I
57	15.603 mm	86.683 mm	-	Medium Tele	-
58	16.022 mm	89.011 mm	-	Medium Tele	-
59	16.448 mm	91.377 mm	-	Medium Tele	-
60	16.880 mm	93.777 mm	-	Medium Tele	-
61	17.319 mm	96.216 mm	-	Medium Tele	-
62	17.764 mm	98.688 mm	Portrait100	Tele	J
63	18.215 mm	101.194 mm	-	Tele	-
64	18.673 mm	103.738 mm	-	Tele	-
65	19.137 mm	106.316 mm	-	Tele	-
66	19.608 mm	108.933 mm	-	Tele	-
67	20.086 mm	111.588 mm	-	Tele	-
68	20.570 mm	114.277 mm	-	Tele	-
69	21.063 mm	117.016 mm	-	Tele	-
70	21.563 mm	119.794 mm	-	Tele	-
71	22.071 mm	122.616 mm	-	Tele	-
72	22.588 mm	125.488 mm	-	Tele	-
73	23.114 mm	128.411 mm	-	Tele	-
74	23.649 mm	131.383 mm	-	Tele	-
75	24.195 mm	134.416 mm	Sports135	Tele	K
76	24.752 mm	137.511 mm	-	Tele	-
77	25.321 mm	140.672 mm	-	Tele	-
78	25.902 mm	143.900 mm	-	Tele	-
79	26.495 mm	147.194 mm	-	Tele	-
80	27.102 mm	150.566 mm	Sports150	Tele	L
81	27.723 mm	154.016 mm	-	Tele	-
82	28.360 mm	157.550 mm	-	Tele	-
83	29.010 mm	161.166 mm	-	Tele	-
84	29.678 mm	164.872 mm	-	Tele	-
85	30.360 mm	168.661 mm	-	Tele	-
86	31.059 mm	172.544 mm	-	Tele	-
87	31.775 mm	176.522 mm	-	Tele	-
88	32.506 mm	180.583 mm	-	Tele	-
89	33.255 mm	184.744 mm	-	Tele	-
90	34.019 mm	188.988 mm	-	Tele	-
91	34.798 mm	193.316 mm	-	Tele	-
92	35.593 mm	197.733 mm	Sports200	Tele	M
93	36.401 mm	202.222 mm	-	Super Tele	-
94	37.222 mm	206.783 mm	-	Super Tele	-
95	38.055 mm	211.411 mm	-	Super Tele	-
96	38.899 mm	216.100 mm	-	Super Tele	-
97	39.751 mm	220.833 mm	-	Super Tele	-
98	40.612 mm	225.616 mm	Sports225	Super Tele	N
99	41.479 mm	230.433 mm	-	Super Tele	-
100	43.001 mm	238.888 mm	Sports240	Super Tele	O