I read on another site that: 1/2 the cylinder measurement + the sphere measurement = diopter strength. Because I have a lot of astigmatism this changes the measurements quite a bit (-3.25 cylinder, -3 sphere). Has anybody else used this equation to...
40139
That's the method we used when buying my daughter's goggles. She ended up with -3.625 (R) and -4.25 (L) so we split the difference with a -4 prescription. She says they work well enough for her, and she has to be read a white board to get her workout during swim practice.
1190630
More strength? If you could explain I might be able to answer. This is a standard adapter for your camera-specific T-ring. You need both to mount/use a camera with a telescope (unless you get real lucky shooting through an eyepiece) - I've used them with heavy film cameras with no problem - on a decent telescope. If the 'scope is lightweight it's probably not good for astrophotography anyway. But the "strength" issue is unclear - are you planning on some other kind of use?
49300
You need to know your glasses prescription. If you're nearsighted, (need correction for distance sight your rx will be a negative number. The lenses come in 0.5 increments. For example I have a -3.75 correction. Since it is in between correction options I ordered a -3.50. (If your in between order the lesser strength). If you are far sighted the correction will be a +.(ie reading glasses). Hope that helps.
1471639
It depends on both the scope and the eyepiece. While the Barlow will increase the magnification by that amount you don't want to exceed the resolving power of the scope since you'll lose image quality and not gain additional detail. There are web calculators available that can help you figure out magnification and resolving power.
521118
Under my experience, 6 degree lens by 25 ft. distance and the result is small than 4 ft. diameter.So 15 ft. away means "Impossible".
676547
I don't know how to measure parallax, but at 25-30 yards, parallax is not a problem. I have excellent clarity throughout zoom range. Worth the money!
1660679
As others have stated there is no magnification. The 1-4 I believe refers to the MOA size of the dot. 1 MOA for more precise aiming 4 MOA for faster sight aquisition. You probably already know this but 1 MOA is roughly equal to 1 inch at 100 yards, 4 MOA roughly 4 inches so the bigger the dot the more of your target is covered and the less precise your aiming. This is a very generalized explanation. Hope it is helpful.
2071543
I physically measured mine using a digital caliper, it can only hold lenses with diameter 65mm safely.
1503374
The 25 and 36 refer to the size of the lens opposite the eyepiece in mm. The larger the lens the more light it gathers. This of course makes for a heavier monocular and a larger one. I have a 10x25 and it is fine. You have to have a steady hand though in using the devise.
498047
Contact Splaqua. I have a smaller deviation in my correction , and in this situation it is suggested to go with the lower number. I know that Splaqua, and probably others, will help with getting the proper correction for each eye in circumstances that call for it.
64369
Because of the difference I would suggest buying 1 pair in each of the diopters you need and swapping out the lenses. For me the difference was only 1 point so I went up a half. They've worked out great.
1922935
Yes - this pair allows for diopter adjustments, which you calibrate when you first use them out of the box (it may make focusing difficult for other eyes than your own, like when you lend your binos to someone else). I think the paperwork included has directions, and if not you can google how to do it :)
65715
I ordered the mask for my girlfriend who is near-sighted. She gave me a copy of her prescription. Under the "Dist" part of her prescription, sphere is -8.5 which is the number I used when I placed my mask order. I am assuming "DV" is distance, and "NV" is near. If so, I believe you would enter the "DV" number. The mask worked great for my girlfriend. She said she could see better out of the mask than her glasses. Hope that helps, Brian H.
336773
Hi, I said I would check the use of the MaxTV glasses with my 4.25 Diopter contact lenses removed.I did, the focus adjustment did NOT go quite far enough to give a sharp focus. It was very close,but not quite there. If you used a two diopter, I don't think you would have a problem, even a 3 diopter would probably work. So for what it's worth. Ang, again, they work as I wanted them to.
2263147
with out the 3x magnifier I wanted the two dot easy to see . with out the 3x magnifier over two dots hard to see them . yeah with 4 dots and no ◾3x magnifier looks like a straight line. I dint want the weight and pay the extra cash. my friend has the 4 dot and 3x magnifier really nice set up. hope this helped you :)
187867
I also noticed the "200" and assumed that it meant 2.00. Turns out that it did: the glasses are indeed a +2.0 correction. I'm not sure whether they just left out the decimal point after the 2, or maybe "200" is just what they call it.
1177288
Depends on what your prescription is. The camera has a built in -3.0 to +1.0 diopter adjustment. You want to buy the one that will allow you to match your prescription. E.g. If you wear +2 prescription, get the +2 and dial it down by 1. You would only need the - if you have to go further than the -3 that is built in. However, I have found that I do not use the diopter. When I have my glasses off, the images on the LCD are blurry. So I shoot with my glasses or contacts, so I can still view the images on the LCD. Hope this helps you decide. Chris