PF-65EDAii Optical Alignment? (2 Viewers)

[mtar925]

I'm a novice/intermediate birder and bought this scope used - in excellent external condition - a year ago, as my first decent spotting scope. I chose the Pentax because I have a collection of 1.25" astronomy eyepieces to use with it. I've been enjoying it with a 13mm Baader Hyperion eyepiece - the contrast and wide field are great.

The 30x delivered by the 13mm is about the maximum power this scope handles well. I tried a few 10mm and 8mm eyepieces and they were all soft. With no other references I thought that was just the limitation of the scope. My birding friends mostly have Swarovski or Kowa scopes and when their scopes are sharper, I've just said "well, you get what you pay for." But the other night I used the PF65 on the sky for the first time, and noticed the diffraction patterns of stars suggest my scope is misaligned internally. The "bullseye" diffraction pattern of defocused stars is badly off center.

Is this typical, or should I seek to have the scope serviced? Can it even be realigned? As the second owner I'm not sure I have US warranty coverage. I have the original box but no paperwork.

Thanks!
Matt in California

 

[Binastro]

Hi Matt,

Yes the scope is out of collimation.

It may have had a knock.

If you try an astro eyepiece you could rule out the supplied eyepiece if the image is the same.

So it could be the prism out sideways or at an angle.

There may be a focus element. It could be that.

The objective is maybe less likely unless it is at an angle.

Certainly Pentax could repair it, but I don't know if they would charge or how much.
As it is not likely an original fault it may cost something, but they may not charge much?

They may charge less than someone like Suddarth Optical as Pentax have the parts, tools and experience.

A good example well collimated should take 100x on say the Moon at high elevation in good Seeing.

Regards,
B.

Good luck.

The serial number would give Pentax the age of the scope.

Some Pentax scopes have split half way, but you would notice such physical damage.

Any scope with an out of focus star pattern that you describe is out of collimation, besides any other defects.

 

[mtar925]

Thanks.

Pentax factory service in the USA seems to be through Precision Camera? The link I found for a Sports Optics service form doesn't work. Any pointers?

I've emailed Suddarth Optics and Mountain Optics in CA too, waiting to hear back.

Matt

 

[Binastro]

Sorry, I am a long way from you.
I don't know.

Someone in the U.S. will probably know about Pentax repairs.

Regards,
B.

 

[Swedpat]

I'm a novice/intermediate birder and bought this scope used - in excellent external condition - a year ago, as my first decent spotting scope. I chose the Pentax because I have a collection of 1.25" astronomy eyepieces to use with it. I've been enjoying it with a 13mm Baader Hyperion eyepiece - the contrast and wide field are great.

The 30x delivered by the 13mm is about the maximum power this scope handles well. I tried a few 10mm and 8mm eyepieces and they were all soft. With no other references I thought that was just the limitation of the scope. My birding friends mostly have Swarovski or Kowa scopes and when their scopes are sharper, I've just said "well, you get what you pay for." But the other night I used the PF65 on the sky for the first time, and noticed the diffraction patterns of stars suggest my scope is misaligned internally. The "bullseye" diffraction pattern of defocused stars is badly off center.

Is this typical, or should I seek to have the scope serviced? Can it even be realigned? As the second owner I'm not sure I have US warranty coverage. I have the original box but no paperwork.

Thanks!
Matt in California

Hi Matt!

I have exactly the same experience when it comes to the optical performance with different magnifications. I earlier had Baader Hyperion 13mm but replaced it with Prometheus 12,5mm.
Apart from that I have Prometheus 17,5mm and Meade 5000 plossl 26mm eyepiece.
I tried with Prometheus 9mm and Televue Delos 10mm eyepieces. But I found the sharpness worsened. And at the same time dimmer image and narrower FOV.
So I just realised that a bit above 30x the image breakdown started to became noticeable. If the image worsened even with a high-end eyepiece like Televue, it shows that the limitation is set by the scope.
I have accepted that 31x is the highest magnification worth to use with this Pentax.

And sorry for the problem with your sample. Has the problem been solved?

 

[mtar925]

I had missed your reply - thanks for the comment. I have not resolved the problem other than to accept, as you have, that my scope just isn't very sharp above ~30x. I did contact 2 different repair services, one told me (honestly I think) that collimation is not adjustable once it leaves the factory. I still enjoy using the scope at lower powers, when I need a light scope to carry for a distance along the trail. It's still a lot better than my first scope, a 60mm non-ED Kowa, which I only enjoyed using up to 20x.

 

[Swedpat]

I had missed your reply - thanks for the comment. I have not resolved the problem other than to accept, as you have, that my scope just isn't very sharp above ~30x. I did contact 2 different repair services, one told me (honestly I think) that collimation is not adjustable once it leaves the factory. I still enjoy using the scope at lower powers, when I need a light scope to carry for a distance along the trail. It's still a lot better than my first scope, a 60mm non-ED Kowa, which I only enjoyed using up to 20x.

It would indeed be good to use higher magnifications to for example astronomy but I am still satisfied with the three oculars I have: 26mm Meade 5000, Baader Morpheus 17,5 and 12,5mm. 15, 22 and 31x are very useful with this spottingscope. And while the magnification is a bit too low for a really good studying of Jupiter and Venus, with 31x the Plejades fills up the entire field of view, really nice!