One thing that I just recently learned from watching a wonderful interview with Jonathan Harris over
at www.emmytvlegends.org, was that the LIS episodes were filmed over a 3 day production schedule and "Star Trek" took 5 1/2 to 6 days to film for the most part.
I find this - very - hard to swallow. Lost in Space was not a half hour series. It wasn't also one of Irwin Allen's "stock footage" shows. They still had 60-75 pages of script to film every week. Camera set-ups had to be made, actors had to be placed, lighting had to be designed, practical effects, like explosions had to be done, and so on. The series also had a number of episodes where "doubles" of the characters were involved, so split screen had to be done. LiS wasn't really that cheap a series. It just didn't have a lot of SFX and, after a time, large numbers of guest stars. In the 3rd season, the series became more elaborate after a half season of being bargain basement, so really, three day shoots seem like a fantasy to me. Someone was telling tall tales or misremembering.
However, if someone said, "some episodes in the second and third seasons of Voyage to the Bottom of the Sea were shot in three days," I'd totally get behind it. That is where Irwin counted his pennies. a half dozen episodes were made up of primarily stock footage with obvious on-set flubs left in. Lost In Space became less costly in the mid second season, and it showed, and MAYBE a small handful were shot that quickly, but for the most part, I'd say 5 days at the quickest.
This is not on you, it's on Jonathan Harris or whoever said it.
Irwin Allen was all about pumping out product and keeping on schedule and saving money. His legendary reputation for being cheap and reusing "monsters" and as Howard Stern is fond of saying "seeing Will and Dr. Smith getting chased around by a guy wearing a spaghetti strainer".
I think people are unduly hard on Irwin Allen. He liked to stretch the dollar, but he also had budgets to meet. He had three series going on simultaneously and these were not stodgy courtroom dramas. He had three complex sci-fi series to run and, from what I understand, would rob Peter to pay Paul in order to meet those declining budgets and stay on the air. He chased trends to feed the ratings and gave the audiences what they asked for. If you look at his series, you can see how much money went into them, but over time they were scaled back. When he had the the money, he spent it. He was all about spectacle. Not sophistication or complexity or characters; he was about scope, danger and action. ABC was the third place network at the time, where all but LiS aired. They weren't gonna be pumping money into his shows if they weren't bringing home the bacon, so to speak. CBS wanted light entertainment and in LiS, that's what they got. Again, on declining budgets. What Star Trek had over all of those shows were creatives who wanted to say more than "stop that monster" or "catch that spy." It's all in the writing. Fox had greater resources, so Irwin's shows tended to look like movies. Star Trek didn't have that advantage. Desilu was a small outfit.
Sadly "Star Trek"'s 3rd season saw the production team stripped of much needed funding and the scripts became, for the most part, only slightly better than the worst of "Lost in Space".
I dunno, man, the worst of Lost in Space is intolerable. Like root canal without Novocaine. The worst of Star Trek still tends to have something to entertain. Shatner, the energy, a weird scene, good atmosphere, something. The worst of Star Trek is "And the Children Shall Lead." The worst of LiS is "Space Vikings" or "Mutiny in Space." After 45 years, I still haven't watched either episode from beginning to end.