Camera and Flash settings calculator for HP42S, DM42 and Plus42

Contributions to this software library are always welcome. Please ensure that you post program listings rather than .raw files. They give a reasonable idea of what your program does without having to load them into a DM42 and you can also include comments in your code. Check out the following link for a decoder/encoder: https://technical.swissmicros.com/decoders/dm42/

You can then copy/paste the listing and post it in "code" tags.
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User avatar
lispm
Posts: 27
Joined: Tue Jun 29, 2021 2:23 pm
Location: Germany

Camera and Flash settings calculator for HP42S, DM42 and Plus42

Post by lispm »

Camera and Flash settings calculator for HP42S, DM42 and Plus42

Just to get used the new EQN feature of Thomas Okkens great Plus42, I entered two formualas into the equation editor, that may be of use to someone.

The first ("CAMERA") recalculates the missing value from any of the three given values (Light Value, ISO setting, f-stop or exposure time).

The second ("FLASH")recalculates the missing value from any of the three given values (Guide Number, ISO setting, f-stop or object distance).

To be able to run it on DM42 I also added a program version ready to be used by the solver.

Image

Used variables:
CAMERA:

LV: Light Value
ISO: Camera ISO setting (... 50, 100, 200...)
N: f-Stop (... 1.4 2, 2.8, 4, 5.6 ...)
t: time in seconds (be sure to enter for example 1/125[s] as 0.008)

FLASH:

GN: Guide Number of the flash at ISO 100 (ex. Nikon SB800 has GN=38)
ISO: Camera ISO setting (... 50, 100, 200...)
N: f-Stop (... 1.4 2, 2.8, 4, 5.6 ...)
m: Object distance in meter (measured from the sensor)


Usage:

Use the solver on SwissMicros DM42, Free42 or HP 42S or CALC on the EQN menu on Plus42.

Plus42 equations:

Code: Select all

CAMERA:2^(LV+(LN(ISO÷100)÷LN(2)))=(N^2)÷t
FLASH:GN×(SQRT(ISO÷100))=N×m

DM42, Free42 or HP 42S

Code: Select all

00 { 107-Byte Prgm }
01▸LBL "CAMERA"
02 MVAR "LV"
03 MVAR "ISO"
04 MVAR "N"
05 MVAR "t"
06 RCL "N"
07 X↑2
08 RCL "t"
09 ÷
10 2
11 RCL "ISO"
12 100
13 ÷
14 LN
15 2
16 LN
17 ÷
18 RCL "LV"
19 +
20 Y↑X
21 -
22 RTN
23▸LBL "FLASH"
24 MVAR "GN"
25 MVAR "ISO"
26 MVAR "N"
27 MVAR "m"
28 RCL "N"
29 RCL "m"
30 ×
31 RCL "ISO"
32 100
33 ÷
34 SQRT
35 RCL "GN"
36 ×
37 -
38 RTN
39 END

Disclaimer:

This program is provided "as is" and "with all faults." I make no warranties of any kind concerning the safety, suitability, lack of viruses, inaccuracies, typographical errors, or other harmful components of this software.


Download:

Download the camera.raw file. The Plus42 equations can be pasted into the equation editor.
The original post can be found here.

TI 55, HP16C, HP41C, DM42, APPLE ][, TRS-80, ATARI 800XL, ATARI 520ST, XEROX 1186 DANDELION, SYMBOLICS 3640, TI EXPLORER II
BLOG: https://yazuu.org/en/showblog_public.php?user=1&blog=
User avatar
48GX
Posts: 180
Joined: Wed May 20, 2020 4:37 am

Re: Camera and Flash settings calculator for HP42S, DM42 and Plus42

Post by 48GX »

Very nice. I will check this out.
Waiting for SM to release DM42 hardware with one additional row of keys.
DM42, DB48X, DM32, HP42s, DM41X, HP35s, DM41L
Raising a next generation RPN/RPL user.
User avatar
GregOldSchool
Posts: 5
Joined: Sun Sep 04, 2022 5:39 am
Location: USA

Re: Camera and Flash settings calculator for HP42S, DM42 and Plus42

Post by GregOldSchool »

Nice little program. Thanks for sharing. Getting back into the RPN game after a long absence. Still have my HP15c which i bought new in 1986. Still works great. Downloaded Plus42 on my iPhone and ordered a DM42. Hopefully the DM42 won’t take too long to get from Switzerland to the USA.

Nice looking D810 also. Looks like an AF-D lens is attached. I’m a longtime Nikon user: D6, Df, D700, F6, FM3a, FE. All working and still in use. I’m afraid I’m going into RPN collection mode as well. Recently acquired a HP42s, HP32sii and 82240A printer off ebay! And thinking about an HP48g+ !
DM42, HP48G+, HP42s, HP32sii, HP15c, HP34c, HP 82240 printer, TI SR-51a.
“For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.” - Richard P. Feynman
User avatar
lispm
Posts: 27
Joined: Tue Jun 29, 2021 2:23 pm
Location: Germany

Re: Camera and Flash settings calculator for HP42S, DM42 and Plus42

Post by lispm »

Nice Collection.

You are right. It's a 2.8/35-70mm zoom lens that I really like.

gtnx

TI 55, HP16C, HP41C, DM42, APPLE ][, TRS-80, ATARI 800XL, ATARI 520ST, XEROX 1186 DANDELION, SYMBOLICS 3640, TI EXPLORER II
BLOG: https://yazuu.org/en/showblog_public.php?user=1&blog=
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