Pentax 10mm XW vs Baader Ortho Classic 10mm
If you look at the 10mm Baader Classic Ortho on the left, and the 10mm Pentax XW on the right, you can understand the title of my post. Recently, well about a month ago I purchased some more eyepieces since it seems the clouds at new moon are never going to end. Above you can see the Baader Classic Ortho 10mm and my favorite eyepiece, the 10mm Pentax XW. The 10mm Pentax XW is my work horse and is found most often in my focuser. However, after reading Alvin Huey's site and a couple of conversations with some well respected observers, I was convinced that I needed to give the idea of less is more in terms of glass a chance. The premise is that you actually can eek out some fainter stars and some fainter details on DSO's by using the less amount of glass elements in the Ortho's. I ordered the 6mm and the 10mm Baader Classic Ortho and recently under a dark sky got to put them to the test. I am not going to do a full review as an outstanding review of them was done by Hernando in April at his blog (link).
Now I have to say, I have the 12mm Delos and the 17.3 Delos and I had the 10mm Delos (sold it) to compare. I did not use the 17.3 Delos per below. The 12mm I did a little comparing to but I did compare all 3 10mm eyepieces. I was shocked to a degree in what I found. Now remember, these are my eyes, my scope and the skies I use are dark, so your mileage as they say, may varying. In examining faint objects I found that the 10mm Pentax XW was just a little sharper, and the contrast was just a tad better to my eye than the 10mm TeleVue Delos. I openly admit to my bias for the Pentax XW's, I love them and enjoy them. However the Delos was so close that if something were to happen to my beloved Pentax XW 10mm, and I couldn't replace it, the Delos 10mm would serve as an equal replacement.
Now what blew me away was the clarify of the 10mm Baader Classic Ortho with its less glass. Yes, with a 50 degree field of view it doesn't equate to the 70 or 72 degrees that the Pentax XW or Delos give, but it did pop a couple to several more field stars and in the case of NGC 5533 it was the BCO (Baader Classic Ortho) that popped the spiral structure, not the Pentax or Delos. Once seen though, I was able to discern the structure and arms in the Pentax XW fist, then in the Delos.
So my take on this notion of less is more is very true. My friend Jorge agreed with me in the field and the Baader did show more than the heavy weight hitters. Now that doesn't mean I'm selling the Pentax 10mm XW, and it is still my first choice, but on those nights when I suspect there is more detail, the BCO 10mm is going in! I can wait to use the BCO in my refractor also. If you want a comparison of the 6mm BCO to the 6mm Delos go over to Hernando's review and take a read. If your really into maximizing detail in the DSO's that you observe, I do recommend the BCO's, especially the 6mm and the 10mm at $74 to $79 each (depending on where you purchase them from).
Pentax 20mm XW vs 17.3 TeleVue Delos
I used the 20mm Pentax XW on several objects and the 17.3mm Delos and found that I much prefered the contrast and color of the Pentax XW 20mm over the 17.3 Delos. I found that I was able to see fainter objects easier in the 20mm Pentax XW and I found that in the 17.3 Delos faint objects, were fainter. It doesn't mean that I didn't like the 17.3 Delos, I did, but the 20mm Pentax XW stays in the finder more often I think. Part of this may be my adaptation to viewing and observing through the Pentax XW's over the last several years and thus my eye sees more with them. I'll keep both the 12mm and the 17.3mm Delos as they fit a niche and I really do LOVE the 12mm, the 17.3 was just a little off but I'm glad I have it.