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.
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.
1052099
According to vortex, it is lower 1/3, not true co-witness. http://www.vortexoptics.com/product/vortex-swing-mount-for-30mm-magnifier
2280932
No lenses do this.An f2.8 lens when racked out from infinity to 1:1 magnification is by definition working at f5.6.The number is the ratio of the distance from the sensor to the aperture divided by the diameter of the aperture.At infinity the aperture is basically 105mm from the sensor (simple lens approximation).At 1:1 the aperture is basically 210mm from the sensor.So the aperture is roughly halved.http://en.wikipedia.org/wiki/F-number#Working_f-number
1198219
Your lens should say what distance it is accross the lens (diameter) or you can measure it.
1469254
I use the 3 and higher for imaging Planets, thet 2X can be used for doubling the power at the eyepiece. The 127 eq is a great scope you should have lots of fun. I had a C5 at one time loved it.
2071543
I physically measured mine using a digital caliper, it can only hold lenses with diameter 65mm safely.
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.
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.
1679461
Its infinitely variable as far as I can tell. Its like twisting a knob. I don't use this very often, only on one particular lens. I almost forgot about it. Thanks for reminding. No issues with this at all. Just guesstimate only for aperatures.
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
1939955
Hello; This is an 8 diopter lens. A diopter changes the focus range of your lens. Diopters come in powers from +1 to +5 (that I've seen). They're also stackable: you can put a +4 diopter on top of another +4 diopter, and conveniently that gives you the effect of a +8 diopter. (Quality does suffer when you stack.) The higher the number, the more powerful the diopter. The more powerful the diopter, the closer you can focus. Specifically: divide 100 centimeters by the diopter power. That's the maximum focus distance of the diopter. A +5 diopter focuses at 20 centimeters or less. A +2 diopter focuses at 50 centimeters or less, so an 8 diopter lens would focus around 13 centimeters or less. Hope this helps. Remember, this lens works when you are in full telephoto.
2173896
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.
1558346
I ordered a pair for myself and 1 pair for each of my sisters in new mexico and texas. We all decided they were not user friendly for us. I don't know the strength but I can tell u this, you cannot see anything unless u hold the item about 1/8th of an inch away from our eyeglasses (we all wear glasses. we were hoping we could get splinters out but we all decided that they would not work for that either. all 3 pairs were thrown in the trash. they just did not work for us. hope this helps u
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.
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.