Possibly stupid Barlow question

[dannybgoode]

My occasional series of possibly stupid questions is in danger on not becoming occasional but hey ho - I'd rather ask than have it right in my head and be wrong .

So, I have a 2x barlow.  If I plop that in my 105/650 which is c. f6.2 does it, to all intents and purposes, just become a 105/1300 f13 when putting details into various software packages to work out FoV etc?  In my head this is what it should be but as I say I would rather check.

 

[vlaiv]

yep

[Robindonne]

2 hours ago, vlaiv said:

yep

If there will ever be a program called Astro Gear, Vlaiv will be The Stig.😍

[dannybgoode]

13 hours ago, vlaiv said:

yep

Great stuff. Thanks as always - you're a big asset to imagers of all levels on this forum

[ollypenrice]

20 hours ago, vlaiv said:

yep

That's one of your shortest ever answers, Vlad! (But it is up there with the best of them...) Keep 'em coming!

lly

[dannybgoode]

57 minutes ago, ollypenrice said:

That's one of your shortest ever answers, Vlad! (But it is up there with the best of them...) Keep 'em coming!

lly

Didn't need to be any longer to be fair