You will learn it fairly quickly, and then you can refine your methods afterwards. To learn without the auto function, I suggest you look up the sunny 16 rule. That is a great starting point. Without the hassle and wait time constraints of film, you should progress fairly quickly. Good luck on your new photography adventure !

PS I learned the sunny 16 rule quite easily back in the day with film cameras, and I wasn't a very prolific photographer.

It is completely unnecessary to use manual modes with a modern digital camera. Just at all. Do not listen to old farts suggesting so. Start with P mode instead.

If you are interested to modify the camera suggested exposure and see the effects, play with exposure compensation adjustment.
If you would like to know the effects of aperture and depth of field, set the camera to A mode.

For advanced photography, manual mode is sometimes needed for night shots, and for studio/still life/flash work.

In practice, composition and lighting are the most important things for a photograph. The less distraction the camera brings, the better. If you can make a shoot in a full auto mode, just do it move on and forget that 50 years old suggestions.

I found this picture describing types of discharges in a tube:
https://www.researchgate.net/figure/A-schematic-of-the-dc-glow-discharge-showing-the-several-distinct-regions-that-appear_fig3_320454510
This is all fine and dandy, but I have questions:

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1) Color Differences:
From what I have seen, the color of a positive-column discharge is usually different than the negative-glow discharge, even when the same filler is used. Why is this?

2) Presence of different glows:
In a neon indicator, there never seems to be any anode glow at all. What makes these certain glows appear in some discharges but not all?

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Thanks!

(1) Electrons speed/enegry/'temperature' whatever you like to call it, is higher at the area near the cathode. So different energy levels of the gas atoms external electron orbits can be excited on interaction. More so, for some gas mixes like Ne/Hg or Ne/Kr or Ne/Xe, Ne glow is excited only around the cathode, with Hg/Kr/Xe dominating the column. See this at plasma globes or at Philps TUV6 glow discharge UV lamp pictured here. To @dor123 - plasma globes sure a run on AC, yet stil this phenomena is observed!

(2) Just no space for a discharge column. Try to excite a nixie lamp in a non-prescribed way - reverse polarity, non-functional pins or so - you'll see the column, in a gorgeous blue mercury glow for many nixies! Anode glow as a thin film around the *anode* seems not to appear in the most common types of glow discharge we see. 

Have you requestet the associated paper?

Under European directives our LED are an average of 117 lm/W, i.e, a 13 watt filament LED is 1521 lumens 😎
CFL here are the same as Brazil @ 60+ lm/W

Essentially 3 flavors:
- Bog standard 100lm/w CRI 80 - also usually what's in fixtures with non user replaceable electronics.
- Ultra efficient home use 210lm/w cri a claimed 80, but with a very clear color tint shift (not at the black body radiator white point, pretty bad)
- Ultra high color quality 90lm/w, CRI 94.

The standard and the ultra efficient ones are the easiest to just buy in stores, but if you order online you can also easily get the others.

Here in Brazil the regular led bulbs are pretty garbage both in operating life and power efficiency.
the norm is something like 89 l/w, some bulbs get as low as 80 l/w. Both 3000k and 6400k variants.
At the same time, we had some CFLs with 64 l/w, almost as high as the LEDs.

In your country, how efficient are they? 

You need a long tube to see this.

@dor123
I am well aware of that, but when running a neon indicator on DC, only negative glow discharge is observed.

Okay, so for me HPS is a bit of a double-edged sword. I think it's more effective at lighting major expressways and thoroughfares (especially in the rain), but MV/LED are far superior in every other application. Residential areas should[/b] be white or at least some form of white in color– things look kind of drab and even apocalyptic in the 2100K of HPS.

So, for me, the personal preference is to keep older mercury fixtures alive through retrofits (think the GE PowrDoor), and to keep expressways and major thoroughfares LED-free. Unfortunately, however, my opinion means diddly squat, so I guess I just have to learn to adapt to the harsh light of 4000K-5000K freeway LEDs. It was good while it lasted, however. Philadelphia only started going LED in 2023/2024, which is far later than nearly every city across the country.

You must run the tube at DC to watch the various discharge properly. At AC, all of these discharges changes location very fast.