TV plossl and ortho focus points??

[spaceboy]

Hi All

I'm gonna be a little specific so I may be a bit of a difficult one to answer here.

I have a 12.5mm Fujiyama which serves me well on the sun at x38 but sometimes the seeing gives me more of a headache than it does offering me anything worth getting a tan on my head for. I would have preferred to stick with the Fujiyama ortho as they are near parfocal with each other but the next step down in magnification is the 18mm at x26 which while it is going to offer up much steadier views can make it that bit harder to pick out those finer details you get with more magnification. As most ortho don't offer up and in between I figured I'd consider a 15mm Televue plossl at x32. The only problem I have is the way I am setup for solar viewing I am VERY limited on inward focus. I know the chances of another member having Fujiyama ortho and TV plossl are going to be slim but I sure there are plenty with the green and black addicts out there who have BGO and TV plossl so all I really need to know is which way do you focus when swapping between the two in or out??

Thanks

[Moonshane]

hi Nick

my BGOs focus way in from my TV plossls. therefore if you can focus with the BGO you will be able to bring the focus out (i.e. make the drawtube longer) to achieve focus with the plossl. 

[nightfisher]

cant help on this one, been so long since i had a scope out proper i cant remember which way the ortho`s change, and dont know about TV plossl, you could try a revelation plossl 15mm and see

[Moonshane]

in fact I used my 12.5mm bgo and my 26mm Nagler to test the maximum in (BGO) and out (26N) focus for setting up my scopes. There was about 18mm between the two. 

[Stu]

Just tried this with a 12.5mm BGO and 15mm TV Plossl on a tree down the garden!

The Plossl focussed about 13mm further out than the BGO so you should be fine (as Shane has already said!)

Stu

Sent from my iPhone using Tapatalk

[spaceboy]

Thanks guys for the quick response. Looks like the 15mm TV is a winner