BARLOWS AND MISCELLANEOUS COMPARISONS -- PART II

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March 7, 1998 : Continuation of the Dakin and Klee comparison.

An hour after sunset I tried some experimentation with my Quantum 6 Maksutov (Q6) and barlows and the moon.

Kind of interesting. With everything I tried, I could sense shadows and dim spots in the image. It looked like out of focus dust. I tried rotating the eyepieces and barlow, but the three or four dim spots stayed put. After much confusion, I realized that it was my glasses that were dirty. Removal of my glasses greatly improved the image of the moon. Not all testing goes as planned.

I decided to use my 1.25 inch 32mm UO Konig with the different barlows on the moon. The magnification of the Dakin and the Klee with the Q6 on the moon appeared to be the same; I couldn't tell the difference. One or both of the barlows might be incorrect with their stated magnifications, or the difference in magnification is not enough for my eye to detect.

The moon served to show some differences between the Klee and the Dakin. The Dakin has a minor ghosting problem, and a slightly softer image than the Klee.

The Klee has a noticably narrower field of view, and the Klee tends to blackout a little easier than the Dakin.

Both images would completely blackout if one moves the eye far enough off axis. Both barlows will get the job done, and each barlow has its strengths and weaknesses with the 32 UO Konig and the Q6.

The Quantum 6 has a 1.75X internal barlow. Using the 32 UO Konig with the internal barlow of the Q6, it was obvious that the internal barlow had less magnification than the Klee or Dakin. I didn't find there to be any real blackout with the internal barlow and the 32 UO Konig. Basic perfection with only a hint of a ghost, which was easily ignored.

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For comparison, I put my 10.5mm Pentax XL into the Q6. In comparison with the barlowed views, the 10.5mm XL required a lot more work with the focuser knob to acquire focus. There is a huge field of view through the XL compared to the barlowed views; but, the view of the XL appeared to be softer. It was cause for much study on my part. The 10.5mm XL would, after a little work, focus to my satisfaction on an object; but, if I moved my attention away from that object and then back, the object would be out of focus. Apparently my eye was doing some compensating with the XL image; whereas, the barlowed views were causing my eye to conform.

Anyway, with the 10.5mm XL on the moon with the Q6, I had the focuser constantly in motion trying to get the desired object to focus and stay focussed. Definitely noticable, especially in direct comparison to the narrower barlowed views. And, the problem is compounded by the fact that there are so many more objects to choose from in the field of view of the XL. I wish I had an explanation for it all; but, I am only an intermediate beginner after all is said and done.

Initially, the only thing my limited experience could come up with is that the Pentax XL is a wide field eyepiece with all the blessings and curses attributed to such a design. I should probably be looking at deep sky with the eyepiece instead of the moon, if I am wanting to 'hear' the snap of focus across the field of view.

Also, with the 10.5mm XL on the moon if one gets too close it will kidneybean. As long as one keeps the eye just ever so slightly back from being able to see the whole massive field of view, then there is no blackout. I turned the deck light on to take notes, and then went back to the XL for another look while the light was on, and it was then impossible to get the eyepiece to blackout -- the light or note taking changed something and made it impossible for me to see any of the XL blackout.

Now I am probably being a little hard on the 10.5mm XL; but, that is my purpose -- to point out every little flaw. In reality, a half dozen people over the last year have told me that for wide field lunar and planetary viewing the Pentax XL's are the best a person can get for sharpness and contrast. Again, I cannot explain it all, but I can venture yet another guess. One should note that the focus problems with the XL could possibly stem from a defect in my eye as opposed to a defect in the eyepiece. My eye has the tendency to do part of the focusing and let the focus knob do the other half; that strange aspect of my personal physiology is much more apparent with wide field eyepieces than with the narrow field eyepieces. It could serve to point out why I sometimes get better results with the simpler eyepieces on the planets and moon than I get with the Pentax XL's. The problem with the simpler eyepieces is that they seldom have enough eye relief.

Of course, the focusing grief could also be due to poor seeing.

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The focusing grief of the XL on the moon caused me to try a few experiments.

I put in my 9mm Intes Monocentric eyepiece for a comparison. This eyepiece has adequate eye relief and a very narrow field of view. There is a huge central ghost that is very annoying, but it can be made to go away by moving the eyepiece off the terminator and putting the whole field of view onto the bright part of the moon.

Once that is accomplished and the ghost is gone, the 9mm Intes Monocentric with my eye had a totally awesome optical illusion. The mountains of the moon took on a three dimensional relief. With a single eye, I was sensing depth. Totally cool.

If that proves to be repeatable on another night, I think the 9mm Intes is going to be a keeper. I wonder if anyone else has gotten that effect out of the eyepiece, or if I am just an odd duck.

The 9mm Intes did seem to possibly have two positions of focus. I seemed to could focus on the central object, or focus on an object on the edge of the field. The 3-D effect seemed to come when a balance was achieved. Hard to explain and something that definitely deserves more time and study. But, I was running out of time.

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I then put in my 8mm Brandon for a look. The moon snapped into focus. Definitely noticable after the difficulties experienced with the 10.5XL. But, to be completely honest, there were moments when the focus was a tad difficult. The 8mm on the moon is probably right at the upper limits of the Q6's capabilities magnification wise.

The 8mm Brandon would be the ultimate eyepiece if it had any eye relief at all. It is strange to have a narrow field of view eyepiece in which the whole field of view cannot be seen. No eye relief makes this eyepiece basically unusable. I don't know how the old timers used to do it. They must have acquired skills that I certainly lack, in order to be able to get usage out of such an eyepiece.

Given much usage at all in cold sub-freezing weather, and I am afraid that my eyeball might actually get stuck and frozen to the eyepiece.

For quality, the 8mm Brandon was far superior in an earlier test to the 9mm Celestron Orthoscopic I had; but, then it had better be at three or four times the price. I sold the 9mm Celestron Ortho when I got the 8mm Brandon.

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Anyway, there you have it. I ran out of time before I got a chance to start trying different eyepieces in the barlows through the Q6 on the moon. With the Dakin and the Klee and the internal barlow of the Q6, a person could spend days trying all the different possible combinations. I was thinking about stacking the Dakin and the Klee with the 32mm Konig or 45mm Plossl to see what happens. With a chance to sleep on it, who knows what else I might could come up with.

The results of the last couple of days were complicated and confusing. I found my skills of observation and explanation severely taxed and inadequate to handle all the different results I was seeing.

If I were to get the Klee matched with the right eyepiece, the Klee in my humble opinion would outperform the Dakin with the same eyepiece. But, more times than not, the Klee would take an eyepiece and turn it into a multi-headed monster. Then the Klee viewing process became a process of trying to chop off one head only to find that the monster still had more heads that needed chopping.

The Dakin at times had minor ghosting, which I so far have not seen in the Klee; but, the Dakin always appeared to have a larger field of view which at times dwarfed some of the potential benefits of the Klee.

The Klee essentially seemed to take the best and worst aspects of an eyepiece and magnified them.

Also, I found the internal barlow of the Q6 to be doing quite well, but I didn't have time to do computations so as to get comparable magnifications going in order to determine if the ghosting problem of the Q6 barlow starts to become an issue.

Thus ends my comparison and impressions to date.

Darwin Bagley

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March 10, 1998 23:00 Mountain Standard Time

'Early morning' for some lunar observation.

I tried a whole bunch of eyepieces in my Quantum 6 trying to test the differences between the Klee and the Dakin.

Another story to share. I set up the scope on a picnic table on my patio covered deck. When I first started viewing, the seeing on the moon would come and go in big gulping surges. The moon would be sharp and then quickly 'disappear' from view or disfocus becoming a big ball of fuzz with absolutely no detail -- a big white cloud. I at first panicked thinking my Q6 had picked up image shift, until the image spontaneously refocused on me. The image would completely defocus, and I kept looking up to see what clouds were getting in the way. No clouds. I must have scratched my head for 10 minutes as I tried different eyepieces trying to figure out what was going on. Then it dawned on me -- I looked back to see that I had left the sliding door wide open. My house in repeated surges was sucking up the freezing night air and then belching out the heat, which would fill up the patio and then spill out into the field of view of the scope from time to time. When I closed the door, all the problems ceased. Good seeing is everything with the Q6.

I must admit that the views of the moon have been very satisfactory. I view when the moon is at the zenith which seems to work well for the scope, and I don't see rivers of heat waves this time of year like I saw last summer during the sultry summer nights.

Now, for the observations I was eager to discover. It quickly became apparent that for lunar observation, the Klee vastly out distances the Dakin. On 3/4 of the eyepieces tried on the moon, the Dakin would ghost them up so severely as to make them undesirable or even unusable. The difference became obvious when the Klee failed to produce ghosting with any of the eyepieces. I had the same 'ghosting' problem a couple of years ago with the 2X and 3X Televue barlows. Those long barlows don't have any internal baffles, so the moonlight reflects off the wall of the barlows and into the image. The Dakin was doing the same.

So, I had the same annoying lunar reflection difficulties with the Dakin as I had with the 2X and 3X Televue Barlows a couple years back. Back then, I sold the Televues and kept the Klee. In actual practice or usage, the only time I seem to barlow is on the moon. I am now hoping to try out barlowing on Jupiter and Saturn because I now have learned that the process can be quite satisfactory if the right barlow and eyepiece are combined.

I tried the 12mm UO Konig, 16mm UO Konig, 24mm UO Konig, 18mm UO Orthoscopic, 26mm Celestron Plossl, ~23mm Kellner, and ~23mm wide field plossl with the barlows on the moon. In every eyepiece, the Klee equaled or beat the Dakin. The Dakin was totally unusable with the 16mm UO Konig in my opinion. From memory, the Dakin was only good with the 24mm UO Konig on the moon, but the Klee was just as good.

I quickly learned my lesson, and I put the Dakin aside.

Then the rest of the session was a test to see how well the internal 1.75X barlow of the Q6 held up against the Klee for lunar viewing. I found the internal barlow satisfactory and better than the Dakin, but I don't think the internal barlow was quite as good as the Klee. I 'stacked' the Klee on top of the 1.75X internal barlow with the 16mm UO Konig and produced a usable image. It was soft at 3.27mm, but I found the image surprisingly good considering how much it had dimmed and softened from the magnification.

I can't find Saturn after a month's worth of snow, but I am eager to see how the scope and barlows would work with Saturn. Need to do some studying.

The 12mm UO Konig by itself on the moon was doable, but it has inadequate eye relief. The image is nice though, what I can see of it. I did barlow it on both the Dakin and the Klee, but the eye relief was still inadequate.

The 26mm Celestron Plossl was okay on the Klee for lunar observation, but not as good as some of the others.

The 18mm UO Orthoscopic showed the dust on the eyepiece in the image. If I would have had my bulb blower handy, I could have rectified it, maybe. However, the image sharpness of 18 Ortho on the Klee was not as good as the Konigs on the Klee. There is no guarantee that with another scope that dust would be visible in the view; but, for my needs, I needed the 18mm UO to perform right with the Q6 on the moon. It did not.

I was very very pleased with the 24mm UO Konig and Klee combination on the moon. Producing 8.37mm, supposedly. Lots of comfortable eye relief, and a great view!

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(March 19, 1998 comments: I had posted the 24mm UO Konig for sale due to its poor daytime performance, but its lunar performance on the Klee had me regretting the decision. As luck would have it, nobody replied to my offer to sell -- until after about a week had passed. After not hearing from anybody for a couple of days, I got to hoping that the 24mm UO Konig wouldn't have any takers; and, in the mean time, I decided to sell the 18mm UO Orthoscopic instead, and keep the 24mm UO Konig. During that same week I also decided to sell my 8mm Brandon eyepiece. I sold the Brandon because it did not have enough eye relief for my needs; otherwise, an excellent eyepiece. I originally had decided to sell the 24mm UO Konig because of daytime blackout problems. I had just figured it would blackout unacceptably on every bright object. I was wrong. With the moon, the Klee actually reduced its blackout problems. I discovered that the 24mm UO Konig and the Klee combination is the perfect replacement for the 8mm Brandon when it comes to lunar observation with the Q6. That explains a little why a friend of mine will sell an eyepiece only to turn around six months later and buy another one of the same make and focal length. Some of your unused eyepieces might prove usable if you could find the right object to use them on. I have met some who have promised themselves to never sell an eyepiece. Their mindset can be somewhat explained by this little story as well; they are waiting for the right scope or the right object to use with that eyepiece. And, as usual, I have again shown that I can easily make mistakes in judgement; just because an eyepiece fails it does not mean that it will always fail.)

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Morning of March 11, 1998, and the night continues.

The 'best' or most exciting 'lunar' combination was the 16mm UO Konig and the Klee in the Q6. That combination is supposed to produce 5.71mm. The Klee gave the 16mm UO Konig more eye relief. I found that very pleasing, as with my long eye lashes the 16mm University Optics Konig by itself is borderline for eye relief. With the 16mm Konig on the Klee, my eye lashes no longer bumped against the barrel of the eyepiece whenever I blinked.

5.71mm was slightly too much magnification producing a softer image than optimum, but I still found it quite acceptable. I don't think a 6mm Ortho would have been any sharper. The 16mm Konig on the Klee is definitely the target to aim for on the nights of best seeing when it comes to lunar observation with the Q6.

Quite a bit of fun, and the Klee is a real winner for lunar observation.

Another story. After a half hour break, I went back outside and put the 16mm Konig on top of the Klee into the Q6. Oh, my! The image had really deteriorated. There was suddenly some ghosting, the scope was relatively hard to focus, and the image seemed dimmer. I was somewhat aiming over the top of a house. Was that enough to make a difference? I checked to make sure my sliding door was closed. It was closed. Some head scratching again. Had the seeing deteriorated that much in such a short time? I then checked to make sure there weren't clouds in the way. No clouds. Then it dawned on me. I pulled out the Klee and eyepiece to see that the internal barlow of the Q6 was also engaged in the light path. I had been viewing double barlowed at 3.27mm; that's 700X! That's too much power despite the perfect seeing conditions.

I assume the ghosting was coming from the internal barlow of the Q6.

Darwin Bagley

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BARLOW REVIEW -- END OF PART II.