Do higher scope magnifications make any sense? (1 Viewer)

[JakeM]

We've regularly used a 5mm eyepiece on our 82mm S2 giving 88x with ~0.8mm exit pupil, and find that quite comfortable and useful in good conditions. Lately out of curiosity I've tried 3.5mm (126x, 0.5mm) which is still surprisingly usable here in good enough conditions, especially across lakes where we most often want it. Eye positioning becomes finicky with so small an EP, and focusing due to lack of fine focus, yet brightness/contrast still seem adequate even in less than full sunlight. So magnification ~1.5x objective diameter still seems useful. I'd like to hear what others have found.

I haven't done resolution tests, but subjectively for what it's worth, even at 126x the daylight view feels normally detailed rather than exhibiting obviously "empty magnification", as often seems the case here when viewing planets.

Absolutely agree. when conditions permit, I frequently use my scope at 120x. (1.5 x objective). i am consistently pleased and surprised at the detail available. my scope has a very fine focus knob (dual) which is a must at higher magnifications.

 

[Borjam]

I own a Kowa TSN-883 and sometimes I use it with the extender at the maximum 90x magnification.

With the right conditions (if turbullence wants to ruin your day there's no magic you can do) it can be really useful. I have enjoyed it even in low light in Winter.

 

[DRodrigues]

By "higher" I mean magnifications with a numerical value greater than half the objective diameter in millimetres.
...

Yes! Since the 90s I used a maximum of 90x magnifications with my Optolyth 100.
Probably since >20 years ago I have been using >=120x with telescopes >=95 mm aperture. Obviously when it makes sense and have atmospheric conditions for it!
As I say at cr-telescopes "for cr-birding power is as important as image quality. For similar image quality, choose always a telescope that can give you more magnifications!" Having said this, I must emphasise the importance of the scope image quality. Is of no use to increase magnifications with a poor image quality sample/model as there are cases of excellent sample/model showing higher resolutions at lower mags than a very good sample/model at higher mags.
Another question rise from tests done with a chart and real tests in the field. One of my Optolyth 100 (not so good as the other sample but that allows the use of astro-eyepieces...), shows higher resolutions at 90x than my X95 at 72x, when testing with a high-resolution printed USAF 1951 chart printed on paper. However, on field work, is frequent to the X95 to allow better reading codes of nasal saddled ducks until 220m. Over that distance, the Optolyth 100 with the >120x solutions allows better resolutions as well is needed to use the 1.7x extender with the X95/X115.
Also beware that I don't have "eagle eyes" since need to use eye-glasses due to astigmatism...

 

[4th_point]

But: With the ED82 I can get up to 75x magnification with the zoom eyepiece, and I use 75x quite regularly. Most modern scopes have zooms that don't allow for such high magnifications. If you want to use higher magnifications - and one of several reasons for getting such a big scope are the high magnifications they can be used at - you have to buy an extender. Now, that's pretty nice, if only for the manufacturers. Most manufacturers don't offer an adapter that would allow you to use astronomical eyepieces. No, that would allow the customer some choice, but who wants that? Looks to me as though the manufacturers learned a lot from Apple ...

Hermann

I have used 75x on my Nikon numerous times. I find it stunning, even with the limited eye relief and FOV.

Last year I watched mountain goats at just under two miles. With their white coat they really stood out, but I was amazed by the detail. I watched them over several days. A few on the first day, then they disappeared (probably to the other side of the mountain), then more would show up the next day. I could see them chewing their cuds and I might have simply imagined it, but I swear that I could see their eyelids close as they napped. One day I counted 23 or 24, and I got to see how they interacted. And the kids running around.

I could have gotten physically closer, but with 75x I could just sit near my tent. I had a lot of fun checking on those goats. I also tried turning the magnification down to what I estimated to be 50x to 60x to see what that would be like, but I always went back to 75x!

I also enjoy watching deer and have been amazed at how much detail is seen at one mile and beyond. That stated, I like to watch wildlife for extended periods of time so the more detail that I can see the better. I think that some people like to identify something and move on, but I find myself wanting as much information as possible and can spend hours just observing.

Jason

PS - as a child I really enjoyed the TV shows Wild Kingdom and Wild America. I think that got me interested in watching animals.

 

[LucaPCP]

Interesting. Here in California I find I can use 45x only in the early morning, when the air is still. After that, I can use at most 35x or so, as air turbulence degrades the image.