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.
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.
1632329
Hi, The focusing distance is always measured from the sensor. Therefore, subtract the distance from the sensor to the front of the lens barrel (approximately 3 inches), and you are left with actual "working distance" of about an inch. Hope that helps.
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.
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When you use it with the little white globe thing, you hold it up against your subject and read the light from there. That's really what this is for. You can also slide the globe out of the way and use it to measure reflected light, but that's going to be fairly inaccurate (since it is hard to point a meter like this with any degree of precision). But still, you point it at your subject, press the button, then look at the reading.
2230132
All I know is that it refers to the unit of measurement of the optical power of the lens. I can't quantify the numbers, but this lamp magnifies very well.
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Not at all. From the description, it is supposed to help people with imperfect vision. I found it pretty useless as I have 20/20. It further seemed like I was looking down a paper towel roll. I am very interested in their other magnifier which can work with a variety of others. Primary Arms makes one but I haven't seen any side by side comparisons.
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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 :)
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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".
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I have found it only to be a slight adjustment. If you take it off the camera then move it in front of something close to focus on. Adjust the ring and you will see a slight difference. Personally I don't use the diopter after initial focus.
1198219
Your lens should say what distance it is accross the lens (diameter) or you can measure it.
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.
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Mika said yes. Mika has done this. I have not tried but the red hole is about 2.5mm and the white hole is about 1.5mm (This was an eyeball measurement without a micrometer.)
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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.
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It does refer to the diameter of your lens, if you are unsure or want to double check, look on the inside of your lens cap!
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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
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Yes, somebody here said +.2 or something like that.It is minor but present; makes screen seem just a little bit bigger.You can get them as prescription lenses if you need more.