Lenses

Lenses are a vital part of the Solar Gun. Each lens is aligned with a specific element, changing Gunshots from the Sun to that element when equipped. The lenses have only appeared in Boktai: the Sun is in your hand and Boktai 3: Sabata's counterattack; The Gun del Sol is stolen early in Boktai 2: Solar Boy Django and used with the Sun of Vice. The lenses are replaced by Terrennials in Lunar Knights.

Lenses are more notable than other Solar Gun parts for several reasons. The first reason is that many puzzles throughout the game require the use of a specific element, so lenses must be changed often throughout the game while other gun parts rarely need to be changed. Also, most lenses are found at special points in the game, such as during cutscenes or after boss battles, making them more notable than other gun parts, which are found somewhat randomly throughout the game. Aside from frames, lenses are also the only type of gun part that has appeared in more than one Boktai game. Finally, every game has some method of changing the element of attacks, with all other methods (Terrennials and the Sol de Vice) serving the same basic function as lenses. In Boktai 2: Solar Boy Django, four lenses are found throughout the game, but they can't be equipped in the Solar Gun.

Leveling Up

All lenses can "level up" in the first game, making them stronger and increasing the size of their spread attack. The lens also becomes physically larger with each level. Each lens starts at level one and can be upgraded to level two and finally level three, represented by roman numerals at the end of the lens' name. A lens levels up automatically once it gains enough experience, which accumulates each time that lens purifies an enemy.

It should be noted that the Luna and Star Lenses are also able to level up, despite the fact that they cannot deal any damage. They can still gain experience, although players must find more creative ways to defeat their opponents. Examples include using grenades to kill enemies, luring boks into sunlights or mummies into fires, or depleting an enemy's health with one lens and quickly switching to one of the non-damaging lenses before the target actually expires. These methods work because the experience is given to whatever lens is equipped when the enemy is defeated, regardless of whether or not the lens was even used. All enemies give a set number of Exp, Kraken-type (15 per tentacle), and Armor-type (50 per armor) together with Cockatrice (28 per bird) give the highest.

In Boktai 3 Lenses no longer need to level up, as Gun del Sol's damage is based on Django's level, but otherwise, the operate exactly the same.

In Lunar Knights, Solgar Gun's don't have a traditional "Lenses System", instead they have one Neutral-Elemental "Lense" made out of Magic metal that is fused with the weapon and cannot be removed, it can absorb Solar Element naturally and other Elements are absorbed by the presence of Allie Terrennials.

Even enemies like Cannon and Grenade Cannon have a "Lense" circuit in them.

List of Lenses

Name	Description
Sol Lens	Lens of the Sun. Purifies Undead. The default lens for the Gun del Sol, found in Django's inventory at the start of the games. This lens is stronger than any other against Boks, the standard undead opponent.
Luna Lens	Lens of the Moon. Uses no energy but... This lens uses no solar energy, but it also causes no damage. It is still useful for solving puzzles or waking up Spirit Bugs, but is nearly useless in combat until it reaches level three. Once it has reached this level, the Luna Lens is able to stun enemies, although it still doesn't deal any damage. Also, the description changes from "but" to "and" at level three. This lens once belonged to Mani. The Luna Lens can also be used with the Phantom Frame and the Chaos Battery. This only works if both aforementioned parts are equipped. This Lens is found during the cutscene Django and Otenko first arrive at Bloodrust Mansion in the first Boktai game. In Boktai 3 it can be found in San Miguel.
Flame Lens	Fire lens. Melts away icy enemies. This lens does extra damage to ice-based enemies, but is nearly useless against fire-based enemies like Burnboks. The Flame Lens has other fire-based properties, as it can melt ice blocks and set Mummies on fire. It's also able to destroy wooden blocks. In the first Boktai it's found at Firetop Mountain, after purifying Muspell. In Boktai 3 it's found at the Lifeless Town. In Boktai 2, Ringo dropped the Flame Lens and it was found by Violet near the Remains, giving it to Django in San Miguel and enabling him to use Enchantment Flame.
Frost Lens	Ice lens. Extinguishes fiery enemies. This lens is the polar opposite of the Flame Lens, doing almost no damage to ice-based enemies but especially effective against fire-based targets. The Frost Lens is also able to extinguish fireballs and lava pits. In the first Boktai it's found at Permafrost, after purifying Garmr. In Boktai 3 it's found in the White Forest. In Boktai 2, Ringo dropped this lens when he fought against Sabata in the Remains and Kid got it, giving it to Django and making the Enchantment Frost available.
Cloud Lens	Wind lens. Can destroy blocks. This lens is especially strong against Cockatrices and some Golems. The Cloud Lens' most interesting feature is that it can destroy all blocks: wooden, ice, or stone. This ability can make some puzzles easier but has few practical uses beyond opening up side paths on earlier levels. Found early in Dark Castle in the first game, and late in Pirate Island in Boktai 3. In Boktai 2, Sabata managed to get it from Ringo and gives it to Django in the Remains, allowing him to use Enchantment Cloud.
Earth Lens	Lens of the Earth. Heals Plants. This lens is strong against normal Golems, but has few combat uses otherwise. The Earth Lens can make some plants grow into ramps and is notable in that it is the only lens other than the Sol Lens that can help Solar Fruits grow at the Solar Tree. In the first Boktai it's found in Sol City, in a "trap" battle. In Boktai 3 it's found in the Ancient Giant Tree. In Boktai 2, Ringo gives this lens to Django in the Aqueduct, allowing him to use Enchantment Earth.
Dark Lens	Lens of Darkness. Dark Gun parts. Received upon beating the first Boktai game for the first time, making it the last possible lens to acquire. The Dark Lens is the Sol Lens' dark counterpart and is stronger than other lenses, dealing more damage than normal against most enemies. The drawback is that it has absolutely no effect on dark-based enemies, such as Steps and normal Boks. The Dark Lens, like the Phantom Frame and the Chaos Battery, is one of the three "Dark Gun" parts, meaning it can only be used if the other two parts are also equipped. This Lens is only available in the first Boktai game and briefly in the opening of the third game.
Star Lens	Stores energy in the Solar Station. The Star Lens is unique in that it can't be used for combat: all shot and spread attacks are disabled while this lens is equipped. Instead, equipping this lens increases the rate at which Sols -- the equivalent of a Single Battery -- are naturally stored in the Solar Station, with the rate further increasing as the Star Lens levels up. The in-game description can be somewhat misleading: holding the A button will charge the currently equipped battery, not the Solar Station. It should also be noted that Django does not have to be in sunlight for the Star Lens to take effect. The Star Lens also makes a number appear over Django's head, showing players how many Sols are currently in the Solar Station. This Lens is obtained after the "trap" battle at the end of Gate of the Dead in the first Boktai game. In Boktai 3 it can be found at Sealed Prison after completing the White Forest bike race.
Astro Lens	The Astro lens is the evolution of Astro Battery and Astro Weapons, and as such it uses energy from the Solar Station instead of the Django energy indicator. This lens can only be obtained in Boktai 3 at special Konami events in Japan. This lens fulfills the same function as the Astro battery of the first game, however, it cannot be used with other Elements lens, it is Sol-Elemental only.