Biggest scope tube sizes

[samf]

I'm hardly the optics expert so forgive if this is a stupid question

"Standard" scope tube is an inch as we know (25.4mm).

Then 30mm if you get the next one up.

Nightforce do 34mm tubes. Others too I'm sure.

And the go up from there too?

I've read a few articles that the light transmission isn't really effect by tube size, neither does quality. The image doesn't get sharper because there's more of it or anything.

Why the bigger and bigger scope tubes then?

[chickapow]

There is some additional light from data sheets I've seen, but like 2-3% only.

Hardly anything to get excited about.

[chookah]

One of the experts will explain, but you need the additional tube size for long range shooting.

Can't remember why

[Kater]

You need the additional tube size for the mechanics needed for long range adjustments.

[greyghost]

Something like a 34mm tube is only needed for very long range shooting where you are adjusting for several feet of drop.

On a standard 1" scope you would run out of drop and windage adjustments way to soon.

[samf]

On a standard 1" scope you would run out of drop and windage adjustments way to soon.

I see.

Righto. Cheers.

[Guliver]

The larger tube is needed to accommodate larger optics, as the magnification increases you need a larger lens to gather the same amount of light.

Notice the huge size of large telephoto lenses on cameras.

[samf]

Thanks for the addition Guliver.

I ended up going with a 32x with a 1" tube for the scope that prompted this.

I was looking for a target scope which will only be in the day at the range so light gathering isn't critical.

It's good to understand it all though.