Saturn and Mars Observation 31/08/18

[Dave1]

Hello everyone.

This is the second installment of comparing my 80mm telescopes. 

The other night I had my 80mm F15 telescopes out for comparison on the planets. The telescopes are Towa 339 80mm F15, Vixen Orion P-80L. They are very closely matched. I was also using my ZWO ADC.

On Saturn I felt the Towa edged it, the Cassini division was slightly sharper, and one of Saturn's bands, which I believe to be the North temperate belt. I could also see the shadow of the globe on Saturn ring. 

On Mars the Towa showed the Albedo marks better than the Vixen. But the Vixen showed the South polar cap far better than the Towa. The south polar cap jumped out in the Vixen, appeard to be a very pure white colour but the Vixen did not show the Albedo markings as well as the Towa. I wonder if this difference is down to the fact I have flocked the dew shield, first eight inches behind the Ota, and upto the baffle from the focuser in the Towa. The Towa only has one baffle the Vixen has 3 baffles. I'm tempted to flock the Vixen. As the contrast performce on subtle contrast details appears better in the Towa, but the Vixen performs better on big difference contrast details. 

I also had out my little 60mm F16. 7 Skylight. Saturn was a real treat in the 60mm Skylight. I could see the Cassini division and there was coulor band on the Saturn globe. My mouth dropped. The detail I saw in this was surprising. I could also see the shadow of the globe of Saturn on the ring.

On Mars I Could quite clearly see the south polar cap, at times I could also see the Albedo marks, very very faint (hey its only 60mm).There was wispy cloud about, seeing conditions were OK to good. Probably a 5-6 on the Pickering scale.

I was mainly using my Brandon 12mm for best views in the 60mm and 80mm telescopes. At times I also used my Brandon 8mm.

Resulting magnifications with the 60mm F16. 7.

Brandon 12mm = 84X.

Brandon 8mm = 125X.

Resulting magnification with 80mm F15 telescopes. 

Brandon 12mm = 100X.

Brandon 8mm = 150X.

I should state the same diagonal and same ZWO ADC was used through out the test. 

In conclusion the main difference on this night between the 60mm and 80mm telescopes was the 80mm showed the fainter more subtle details better, making them easier to see. 

Dave

[MarsG76]

Very nice comparison... the way you describe it seem like you would have matched my last views of Mars through my 8" SCT at 290X!!

And I'm surprised at how much detail you saw on Saturn through a 60mm telescope.... I remember seeing Saturn through my 60mm TASCO as a tiny disc with just barely discernible rings, but no cloud-bands or definitely no Cassini division. GOOD EYES!!!!

 

[Dave1]

3 hours ago, MarsG76 said:

Very nice comparison... the way you describe it seem like you would have matched my last views of Mars through my 8" SCT at 290X!!

And I'm surprised at how much detail you saw on Saturn through a 60mm telescope.... I remember seeing Saturn through my 60mm TASCO as a tiny disc with just barely discernible rings, but no cloud-bands or definitely no Cassini division. GOOD EYES!!!!

 

Ah yes, well I was very surprised with the 60mm. I was in awe confusion in a good way. Everything is minute in the 60mm with only 60mm worth of resolution to work with. When I went from the 80mm to the 60mm, it took awhile for my eye to become accustomed to the 60mm and the details to start showing. The first detail to show was the Cassini division. The moment when I saw the North temperate belt made me shocked in awe, that however was not on show most of the time, only in those brief moments of exceptional seeing. 

Dave.