Barlow question

[Astroscot2]

I was looking at buying a good quality 3x barlow which would give me the optimum resolution for my scope / camera pixel size. for planet / moon imaging. As I already own a TV x2 barlow is there any advantages / disadvantages to adding an extender to increase the magnification?  example a 60 - 70 mm extender would increase the magnification to 3X, far cheaper than purchasing another barlow?

 

Mark

 

 

[vlaiv]

2 minutes ago, Astroscot2 said:

I was looking at buying a good quality 3x barlow which would give me the optimum resolution for my scope / camera pixel size. for planet / moon imaging. As I already own a TV x2 barlow is there any advantages / disadvantages to adding an extender to increase the magnification?  example a 60 - 70 mm extender would increase the magnification to 3X, far cheaper than purchasing another barlow?

 

Mark

 

 

I think it is mainly convenience factor. Optically - probably not much difference if any.

Higher power barlow elements tend to have shorter focal lengths, so achieving working magnification does not require additional distance to focal plane. With additional distance and x2 barlow - actual focal plane moves further away, so you will need additional back focus to go along with that extender (or another extender before barlow element to make it easier to reach focus).

[cajen2]

You might also consider an ES 3x focal extender. I have the 2x and it's very good.

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-2x-3x-5x-barlow-focal-extender-125.htm

 

[Guest]

I have a 3x barlow in my kit and it is the one i use the least.  Honestly i could probably live without it 90% of the time.  I use it primarily to look at the moon when i want to get inside the craters. 

[Mr Spock]

The TV x3 Barlow according to reviews has better image quality than the x2.

Being visual only I chose the Powermate x2.5 as it allows me to use my 18mm, 12.5mm and 9mm orthos on planetary. I don't know if it would make a difference for imaging but it is better quality than the Barlows.