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.
1177291
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
998685
It says"Magnifier 2 5x ...". I believe the 2 is just part of the product name, there is no decimal point. A 4" lens diameter can't be 5x, they just can't make them. I even asked my eye doctor about ordering one from him. So I think the lens is a 1.5x with a 3x inset as the lower information on the page description says,. I sent mine back as the one I bought at a fabric store was better. I think you could find a 2x or 2.5x in a large lens with a 6x inset somewhere else. The around the neck batteries wear out very fast so you need rechargeable batteries for cost reasons.
625014
Don't use it much anymore. When I did, I tested it and found it doesn't make much diff. The thing is, it's field of view widens as it gets further away. So if you measure something that is very small from a longer distance, you'll get a bad reading. When I used it, I was measuring small packages 5x8 inches from a very close distance like 1-2 ft. Sorry I can't be more help.
4681
Actually I am not aware of anywhere online that shows measurement. I use the eye dropper bottle that comes with the order and basically do the math myself.I always drink a full glass or cup of distilled water whether I am adding adding 3 drops or 23 drops.
2042953
A 6mm eyepiece will give you about 75x magnification. I get better views of Jupiter in my scope with 4mm and 3.8mm eyepieces at about 115x. I don't like using a Barlow.
496261
The distance between the center of the pupils when focused on infinity (Interpupillary Distance)is not given in any of the specs for these binocs.Jim
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.
1098705
I also see an oblong dot, almost a set of dots that seem not round. I was diagnosed a few years back with a "mild astigmatism", and although I do have glasses, I generally do not wear them. I was unsure if it was the astigmatism or a faulty unit, so spoke with Trijicon on the phone and they said to exchange the unit with a new one. I did so through Amazon and found that the new unit did the exact same thing. I believe that its the astigmatism, and although mine is so mild that I don't have the need to wear glasses, it still makes the laser dot seem oblong.
1190631
As per previous answer it is just standard adapter for a camera specific T ring so you can attach camera to telescope that has 1.25 eyepiece It will not give more "strength" (I assume you mean magnification).
2103644
Iso wont make a difference. You will need to do some math to calculate your "effective F stop". Ne = N(1+M/p)N = f-numberNe = effective f-numberM = magnification = extension from infinity focus / focal lengthp = exit pupil diameter / entrance pupil diameter
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.
1640292
I guess you didn't have the link http://www.amazon.com/Vortex-Solo-10x36-mm-Monocular/dp/B00161ZI4A/ref=cm_cd_al_qh_dp_t Specs: Eye relief: 15 mm; Exit pupil: 3.6 mm; Linear F.O.V: 325 feet @ 1,000 yards; Angular F.O.V.: 6.2 degrees; Close focus: 16.4'; Length: 4.9"; Weight: 9.7 ozs.
1595888
I got 2 lenses with mine (from a year or so ago) a 6mm and a 15mm. The 15mm lens gives a wider field of view while the 6mm lens "zooms" in on the target object for more detail - they should be labeled.The cap with the hole in it is used to calibrate the telescope mirrors (it's called a Collimation cap) - you should not need to use it. If you are interested in all the ins and outs of collimation, you can google it, but I've had my scope for over a year and have not needed to go through the process.
1213448
+3.5. And, besides: I tried them in a store and found that they they work superbly for adjusting on the fly between -6 and +3.5 correction (more or less). The optics seem excellent. As a fashion statement a bit awkward but hard to make the double lens system look better. The dial adjusters are discretely positioned and effective. I have no idea about durability.
234982
Pardon my terseness, but the answer to this question is clear from the product description. Only two measurements define a cylinder (length and diameter). The product advertises a 3.5" diameter and telescopes to over 36" in length. If your measurements are accurate - then it fits.