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.
2259983
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.
77652
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.
294870
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.
82129
I think -4.0 and -4 are the same. If you are near-sighted, you should choose negative.
518034
1/2 a cup exactly then subtract 3 1/2 tsp. I use a syringe type dropper made for oral medicine to measure. Your results may be a little different... but this is a really good place to start. For me this makes round death stars. If you add too much you get fun house mirror death stars shaped all cone like on the top. (which is the bottom of the mold)
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.
98633
Its actually not bad. I sighted in at 25yds and at 50yds. At 50 it was a little faint but you could definitely see it.. make sure you're not using a bright white paper to sight though as it will wash out. I really wasnt even expecting that for the price. It's worth the 12 bucks.
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.
1645861
Paul, thank you. From the specs alone, I agree, but I think there must be some significant difference between the two sets. The only thing I can see from the specs is something about the eyepiece adjustment.
1379828
I am just guessing but I assume it is 2 and 1/2 magnification; I have one of these and the cord that you put around your neck can be adjusted to bring your work into focus so I wouldn't worry about it. I love mine! Well worth the money!
1211051
What I did was, using a set of metric vernier calipers measure the outside diameter of bothe the Ocular lens (eyepiece) and the objective lens. Then using the Butler creek measurement table, chose the size as close too or slightly smaller than that measurement. I too had issues with finding what I needed and I did have to surf about a bit, but I finally found a table that had all of scope cap sizes and measurements. Hope this helps
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.
1025376
Sorry, but I don't have an expert answer. Here's what I did. I simply measured, with a very accurate ruler the exact outside center cross distance on the lens. No matter if it measures in inches or metric, just Google the number for a conversion. Worked perfect for me on the first and subsequent orders.. The covers fit perfect, are very well made and I'm very happy to have this protection for all of my lenses. Hope this "grass-roots" method works for you. Bob D., Maine
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.
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.
771645
The distance from the center of the 15mm rod to the center of the lens opening is adjustable between about 3.75 inches to 4.5 in. You just need to take a ruler to your rig and see if this your distance falls within that range. I got my matte box out and measured it. I just hell up a ruler so I could be off a little.