My husband does not share my love of Harry Potter. Dumbledore, Hogwarts and Quidditch leave him cold. But he loves me, and I love the books, so he made it his business to find out when the next Harry Potter film was coming out (July 15), and when it could be seen in the best of all possible formats, IMAX 3D (July 29).

Since it was opening day for this film in IMAX, we knew we’d have to wait in line to get decent seats, so we lined up at Edwards Mira Mesa Stadium 18 at 5:30 for the 7:40 PM show. We’d gone right after work, and given that we’d be in the movie until about 10PM, I bought concessions – a practice we call “conceding,” since we know the food is both terrible and overpriced. I got a hot dog, a medium popcorn, a medium soda, and some fruit gummies, which cost almost $20. IMAX movies cost more, in this case $16.50 each, so by the time we took our seats, we were already in for over $50.

Half a C note.

My friends, as much as I love Harry Potter, this gave me pause.

Another thing that gave me pause – the much-vaunted, totally immersive 3D effects in this movie only lasted for about the first 15 minutes. Then a flashing red symbol told us it was time to take off our 3D glasses, which remained perched on top of my head for more than 2 hours.

The final thing that made me question my decision to spend extra to see this movie in IMAX 3D? The screen is not much bigger than a regular movie screen.

Now, if you’ve ever seen a movie at the Ruben H. Fleet Science Center in Balboa Park, you’re thinking, “What? No way! IMAX screens are huge!” And that IMAX screen is huge, something like 75 feet wide, and completely surrounds your field of vision in a curved dome. But the IMAX screen at the Fleet is different than the IMAX screen at Edwards Mira Mesa. It’s what’s called an IMAX Dome theater, and it’s the only one in San Diego (and was the first in the world, by the way). What’s at the Edwards Mira Mesa is known as a IMAX MPX theater, which is rectangular, and according to the IMAX website, is “specifically designed to enable multiplex operators to more cost effectively enter into the IMAX® theatre business, by retrofitting an existing stadium seating auditorium or via an economical new build.” In other words, sell you “IMAX” without having to build a new theater. Which means the screen is not much bigger than that of a conventional theater – and only about 1/3 the size of traditional IMAX.

Now when you pay your $5 extra per ticket to see an “IMAX” movie, they really work hard to convince you that the movie you are about to see is the most pristine, incredible, optimum movie experience imaginable. An usher tells you that the sound will be incredible, even upsetting to some people, but that they won’t turn the sound down – it’s a bajillion watts and 999 speakers behind the screen, all aimed at you, and that’s the ride you paid for, buddy. And it is good, don’t get me wrong. The sound is probably the best I’ve ever heard in a theater.

But is it worth twice the price of a regular movie? Or even 3 times?

I decided to do a completely subjective, non-scientific experiment. I’d seen Harry Potter and the Half-Blood Prince in IMAX 3D at Edwards. Now I would go and see it again, this time in “standard definition” – i.e., a regular theater, at regular prices. I’d found out if the extra I paid for “IMAX” was worth it to me.

For my second viewing, I chose the UltraStar Del Mar Highlands. UltraStar is my favorite movie theater chain, because they feature really clean, crisp digital projection in all their theaters, but cost the same as a regular movie (and often less – movies there are $5.50 all day Tuesday, and if you clip the coupon you’d find in the San Diego Union-Tribune every Friday, they are $5.50 anytime). Essentially, they improved my movie experience without passing the cost on to me. I like that.

It’s still a long movie, and I hadn’t had dinner, so again, I conceded. This time I used another coupon UltraStar offers in the newspaper, and got a medium popcorn and a medium soda for $6. Boy, I thought, I am becoming a cheap date. So far I’d only laid out $11.50.

I was in Theater 8, and I asked the usher how big the screen was. He told me it was 18 feet by 37 feet. To my eye, it was only slightly smaller than the IMAX one at Edwards.

I saw the movie again, and it was just as thrilling, just as immersive, and just as magical as my previous viewing. Yes, “IMAX” was better in terms of picture and sound quality, but twice as good? No, not nearly.

So I may be saving my husband a lot of money when we go to the movies in the future. And if I ever want to go have a real IMAX experience, I’ll consult bigmoviezone.com, which allows you to search for theaters by type of projection or whether the screen is rectangular or domed.

Yay for cheap dates!