Hi Phil,
I am eagerly waiting to see the results. My gut feeling is that they are going to be very close optically and it will come done to very minor subtle differences between them, as to why you would prefer one over the other.
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Originally Posted by issdaol
Received my First Pentax Eyepiece Yesterday a SMC XW 10mm, (  fok4tel ), for a second hand unit it appears to be in Pristine Showroom Condition.
Assuming clear skies and no other interruptions I plan to do a direct comparison of this against my TV Delos 10mm which should arrive tomorrow afternoon. |
Is the purpose of buying both to see which of the two you prefer and then you will keep the one you like best and sell the other one?
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Originally Posted by issdaol
Overall the Pentax appears to be extremely well constructed similar to what I would expect from Takahashi or other professional Astro Company.
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The Pentax is a very high quality product, in every respect. Particularly when you compare it to something like the floppy and rattly instadjust setup on the TV Radians and Nagler T4's. Shake a TV Radian and you're almost guaranteed to get a rattle from the slop in the instadjust. It sounds like something is loose inside the eyepiece, but it's only the instadjust. Some are less rattly than others. Some almost don't rattle at all, others sound like a baby's rattle.
That having been said, Televue have addressed this issue and the DELOS also has a really nice eyeguard adjustment system. It is a split system with a lock ring and you slide it up and down the barrel, then turn the lock ring to lock it in place. It has graduation marks on the barrell so you know the relative position of the eyeguard it all times. Shake the DELOS and it doesn't rattle. It's a high quality product also. I really like TV's new system. Why did it take Televue 15 years to address the instadjust system?
Quote:
Originally Posted by issdaol
I was very surprised by the inbuilt EP Height Adjustment. Simply twisting the top part of the Eye Cap makes fine adjustment in height of the EP/Cap. First thoughts are that this is very nice but I will reserve judgment for how it works out practically.
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I am not sure if you have used eyepieces with long eye relief and an adjustable eye guard before? If not some advice.
The following applies to both the Pentax XW and the DELOS. It is important that you spend the time to set the eyeguard height correctly to suit you. This can take some experimentation if you haven't done it before. Once you get it set right for your own needs you shouldn't have to adjust them again.
As a rough guide if you wear eyeglasses start with the eyeguard about 20% of the way up from its lowest position. I have mine up just far enough so that the lenses of my glasses cannot make contact with the eye lens of the eyepiece. Take your glasses off and hold them against the eye guard of the eyepiece to check this. This is important. If the two glass surfaces contact you can destroy the coatings of both.
If you don't wear eyeglasses start with the eyeguard set to the very top position. This will act as an "eye guide" and make it a lot easier to hold the exit pupil and eliminate "blackouts". I know of a couple of people that bought a Pentax XW, left the eye guard right down, experienced horrendous blackouts and quickly sold the eyepiece, without even being aware the eye guard was adjustable.
Once you get your Pentax XW set correctly you will find it to be an extremely comfortable eyepiece to use for long periods and very "eye friendly". I haven't used my new 6mm DELOS yet but I am assuming it will be similar to the XW's, based on the eye lens and eye guard design.
Good luck with them. They are 2 high quality products.
Cheers,
John B