X derivations (1 Viewer)

[DRodrigues]

...

• The gain in resolution by zooming isn't so evident as zooming the STX and I have to test it on field conditions.

As the APM SZ don't reach focus using the 0.5x focal reducer, I might test a pair of Baader zooms to see how resolution results with wider FOVs - 88% more, as mentioned on the original LTX post...

The zooming only showed more the aberrations on field work conditions...
Will return to the reducer with the Baader zoom to see how resolution results...

 

[DRodrigues]

I did tested and the result is:
View attachment 1556668
This solution almost don't vignette at lower mag - 40x - and with the resulting eye-relief (the FSA-L2 induces an increase of the ER...), makes almost the eye-piece "invisible"! Also noticed that zooming the FSA-L2 seems to not increase resolution, so the loss of ER isn't no longer a problem - will use only the X115 zoom... I have to test it on field to decide if is worth-while or not i.e. if besides the wider AFOVs and higher mags, there is a resolution gain?

Field work approved!!! This solution made my day!...
On 30-70x mode (without the extender...), I spotted a nasal marked acuta at 235m that I almost could read the code. Added the combo and voilá!

With the extender I would also read the code but wouldn't mount it so fast as with this solution.
Tried to digiscopy without the combo, at 70x, and didn't managed to take a photo where the code would be visible as on this.

 

[DRodrigues]

WTX115 with the Swaro 1.7x extender
I concluded that the WTX isn't a replacement for the use of the 1.7x extender, since this last result on better image quality (as expected...), and resolution. However, is possible to use the WTX combo with the 1.7x extender also: - I had concluded before that the use of 2 extenders didn't resulted on a real gain in resolution. So the WTX combo might increase resolution on some extreme situations and I will try to confirm it during field work but it will take long time...
I tested also the Nagler 22 instead of the Ethos 17, but continued to prefer the Ethos.
Meanwhile remembered to test with a Pentax XW20, there is no vignetting at minimum mag and the image quality seem to increase, although with only 70º - the FOV is reduced 15%, compared to only the STX. The combo result less long and less heavy - will see how it behaves on field work.

 

[DRodrigues]

Another alternative to the BTX and this zooms!!!...
... as I want to maximize FOV ...

A new version with a pair of Masuyamas 2" 32mm 85º - the FOV increased but still is 15% less than the X115 at 30x.



I prefer the TMB bino combo shown at CR BinoBirding ...