| Quality | f/5 newtonian reflector | f/8 achromatic refractor |
| On-axis sharpness |
This was very good to excellent on all subjects |
I found this to be good to excellent on Jupiter & stars |
| Off-axis sharpness |
It performed quite well, better than anticipated actually. Visually not much difference than F8 which was a bit of a shocker to me! I was expecting it to perform worse in this area at F5! ( It pays not to predict!) |
Off-Axis it performed quite well. Good clean sharp focus. Slight anstigmatism on stars visible at the last 10% AFOV. |
| Contrast |
Dark back-ground on DSOs. Jupiters dark regions & the GRS more readily visible than some of my more up-market EPs. Did a great job in the contrast department. |
Fairly dark back-ground on DSOs. Jupiters dark regions & the GRS more readily visible than some of my more up-market EPs. Did a respectable job in the contrast department. |
| Field Flatness |
Focusing on an object On-Axis & letting it drift to the edge of the field, I found some de-focusing was apparent. Better than some of my other EPs. I found this to be not overly bad. A fraction worse than at F8. |
Focusing on an object On-Axis & letting it drift to the edge of the field, I found a little de-focusing was apparent. Better than some of my other EPs. I found this to be not bad. |
| Light Transmission |
Same as F8 test. I compare this to a Vixen LV for light transmission. |
I found this to be ok. I could probably compare this to a Vixen LV for light transmission. |
| Chromatic Abberations |
I noticed nil amount of this |
As this test was conducted in an F8 achromatic refractor, I am not in a good position to judge in this area. Suffice to say it was no worse than any other eyepice I own. Using the aperture mask on jupiter, very little chromatic aberration was visible. |
| Eye-Relief and Comfort |
Slight kidney beaning. Takes all of 30 seconds to learn where to position your eye for optimal results. Not a problem for me. Since the F8 test I have learnt this EP has 20mm eye-relief. So it would be ok for glass wearers. |
I found the eye relief to be sufficient for me. IE: I did not have to roll the eye-cup back. If I had to guess, I would say it was between 10-15mm. If you wear glasses this EP may not be suitable, although rolling the cap back may be successful. This eyepiece does have a slight kidney bean problem. But I would say it was not overly annoying. Takes all of 30 seconds to learn where to position your eye for optimal results. I found out it has 20mm ER, making it ok for glass wearers |
| Ghosting |
I did notice when Jupiter was being viewed off-axis there was a "ghost of jupiter" directly on-axis. This was just discernible however, & did not really take away from the view. Some may find it off-putting , but I did not. No ghosting visible to my eye on bright stars. This is not visible to me at F8 |
Nil |
| Scatter |
Better than most of my up-market EPs on Jupiter |
Better than most of my up-market EPs on Jupiter |
| Field Stop Condition |
I saw no 'ring of colour' around the field stop. Nothing to report in this area. |
I saw no 'ring of colour' around the field stop.
I also positioned the half moon just out of the FOV. The light grey colour in the FOV was evenly illuminated. I saw no long bright spikes of light spearing across the FOV as I see in some of my EPs.
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| Build Quality |
Looks ok to me, Although at a quick glance you can tell it's not a $300 EP. The only thing that lets it down slightly is the cheap chrome job done on The barrel. It has a safety under-cut. It fits in the focuser slightly loose, with a deflection of approx .75mm when doing up the retaining screw. The 'blackening' job done on it is not up to standard. IE: The inner barrel thread where a filter might screw on is not black enough.
It looks to me to have the built-in barlow system. Somewhat similar to the LV in design. With the LVs you can take the barlow off.....With the ED-2....Just don't do it! You'll have elements flying all over the place if your not extremely careful. Not recommended.
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Looks ok to me, Although at a quick glance you can tell it's not a $300 EP. The only thing that lets it down slightly is the cheap chrome job done on The barrel. It has a safety under-cut. It fits in the focuser slightly loose, with a deflection of approx .75mm when doing up the retaining screw. The 'blackening' job done on it is not up to standard. IE: The inner barrel thread where a filter might screw on is not black enough.
It looks to me to have the built-in barlow system. Somewhat similar to the LV in design. With the LVs you can take the barlow off.....With the ED-2....Just don't do it! You'll have elements flying all over the place if your not extremely careful. Not recommended.
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