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Low-Light Performance Calculator |
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Dogger
Optics Jedi Master Joined: January/02/2007 Location: Ontario, Canada Status: Offline Points: 8921 |
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opticsmike, not an easy task to distill all the physics behind this issue into a form that the laymen among us can understand and use but I applaud your efforts! Thanks,
Craig
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God save the Empire!
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Ed Connelly
Optics Retard God of no Chihuahua Joined: December/16/2007 Location: USA Status: Offline Points: 24225 |
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Gunshow75
Optics Apprentice Joined: December/23/2004 Location: Kentucky, USA Status: Offline Points: 209 |
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Ed, I think you captured the essence of the matter. Trying to distill some kind of homebrew doesn't make it physics.
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Tom |
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Dogger
Optics Jedi Master Joined: January/02/2007 Location: Ontario, Canada Status: Offline Points: 8921 |
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While that may be true it's also outside the capability of most of us to understand the physics behind this effort. Will have to leave that to you more knowledgeable folks.
If a system even with imperfections helps us to understand the low-light issue more succinctly then it is still a worthwhile effort.
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God save the Empire!
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mike650
Optics God Joined: May/14/2006 Location: West of Rockies Status: Offline Points: 14569 |
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“A hunt based only on trophies taken falls far short of what the ultimate goal should be.” – Fred Bear
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Gunshow75
Optics Apprentice Joined: December/23/2004 Location: Kentucky, USA Status: Offline Points: 209 |
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Please don't sell yourself short. All of you are more than capable of understanding how optics work. What is important to me is that you are not misled by things that are not true. Unfortunately, Opticsmike's "system" doesn't just have imperfections, it is fundamentally wrong in many ways. |
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Tom |
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opticsmike
Optics Apprentice Joined: September/09/2008 Location: Amherst, NY Status: Offline Points: 185 |
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Lets see, so far gunshow75... 1. You referred to a source that suggested that the Stevens' Power Law is less accurate than the Weber-Fechner Law, while the article made a ridiculous comparison of a complex form of the Weber-Fechner Law to the basic form of the Stevens' Power Law, without acknowledging the use of modernized complex forms of the Stevens' Power Law for complex scenes. Complex forms of brightness calculation do not even apply to my calculation, as I have based the brightness scale upon a target with a uniformly dark background and surround, which is the basic form of brightness scaling calculations. 2. You assumed that my graphs were reflecting magnification as the cause for light gain instead of reading my explanation of the exit pupil/eye pupil relation as causing the brightness to increase with magnification. 3. Instead of outlining why you believe the Steven's Power Law is not appropriate, you just say it's like talking to a liberal, yet I had provided numerous sources from highly regarded recent studies supporting the Steven's Power Law as more appropriate. 4. You say my Theoretical Light Gain and Realistic Light Gain definitions should be omitted because luminance can't be measured with our eyes. Ever hear of a light meter to measure light within an area? Or how about making calculations based upon known criteria? Well supposedly you didn't, and you instead continue to blame your misunderstanding on my so-called half-truths. 5. You utilize an example of my calculation at a magnification point at which exit pupil/eye pupil relation is no longer a factor when exit pupil diameter is less than eye pupil diameter. You then assumes that is reason enough for exit pupil/eye pupil relation to never be a factor. 6. You incorrectly redefine my calculation to eliminate the relation of Scoped-Eye-Pupil-Light/Uscoped-Eye-Pupil-Light so that it deduces to just magnification as the sole factor, and then you say that I would have everyone believe that my calculation is all about magnification. 7. You sarcastically write off the Stevens' Power law because it's used for determining brightness scaling for computers, even after I have discussed the real world tests that make it applicable. 8. You had claimed three times now that target image resolution does not increase with magnification. 9. You still didn't understand exit pupil/eye pupil relation so you just claimed it was irrelevant because it's not used for Twilight Factor nor Relative Geometric Brightness. No kidding. That's one of three reasons why my calculation is a significant improvement. 10. You created a formula that simply multiplies eye pupil diameter into it, and then proved that the calculation can produce the same result without eye pupil diameter. No kidding, but you left out the exit pupil/eye pupil relation of my calculation which can not produce the same result without eye pupil diameter. 11. You continue to reject something because you do not understand it. You can not reject something unless you understand it and you can understand what is incorrect. 12. Your repeated mistakes and unjustified judgements are reason enough to show everyone that you don't have a clue. 13. Oh yea, your sarcasm is disrespectful and unhelpful. 14. Pretty much anything you say at this point is meaningless to me. |
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opticsmike
Optics Apprentice Joined: September/09/2008 Location: Amherst, NY Status: Offline Points: 185 |
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For everyone else, this should help illustrate the transition process...
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Skunk
Optics Journeyman Joined: November/05/2007 Location: France Status: Offline Points: 323 |
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+1 on points 1-10
+100 on points 11-14
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Let me give you my two scents worth
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cheaptrick
MODERATOR Joined: September/27/2004 Location: South Carolina Status: Offline Points: 20844 |
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supertool73
Optics God Superstool Joined: January/03/2008 Status: Offline Points: 11814 |
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I don't think Tom (Gunshow) is trying to pick a fight, he just wants to make sure all details are in fact correct. Regardless of the debate, this has been very educational for me and probably wouldn't have been near as good without the debate. Good job guys.
My low light tests consists of this. If it is under $200 don't bother. $200-$600 use mostly as a day scope. $600-$1000 morning and evening time is going to be looking pretty good. $1000+ watch out animals I am shooting you know matter what time it is. |
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Lifetime warranty and excellent customer service don't mean a thing when your gun fails during a zombie attack.
"A Liberal is a person who will give away everything they don't own." |
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koshkin
MODERATOR Dark Lord of Optics Joined: June/15/2004 Location: United States Status: Offline Points: 13182 |
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All right, since cheaptrick has landed I feel that I should intervene before he goes ballistic (again).
A couple of points: 1) Gentlemen, we have to learn to disagree in a civilized manner (or I will let loose THE cheaptrick) 2) I have not really looked into the technical details of the argument. There are two reasons for that: there was a bunch of stuff linked that I did not have time to read thoroughly and, for my purposes, this calculator is not really useful since I mostly compare different brands and designs to each other. When I have time, I will dig into it a little more. As a possible suggestion to opticsmike, have you considered writing a proper white paper/application note on what your calculator is doing and why? By referring to a bunch of different sources without a reasonably coherent and verbose explanation of what you are actually doing, you are making sure that none really understands what you are up to except for someone hell bent on proving you wrong. For example, I have some fairly relevant background in this stuff, and without spending some time on this, I do not find what you are doing here at all clear. See if you can come up with a way to explain it to a person without an optics background. To gunshow75, if you disagree with someone, try to do it in a nice way. When you write a reply that gets you all emotional, try re-reading it a time or two before you hit the "Post" button. I do not recall what you do for a living, but I remember when I spent a lot of time in an academic environment, being rude and obnoxious was an absolute norm. Having several scientists in the same room was akin to watching several spiders in a glass jar: only one was going to come out alive. Out in the real world, politeness is a virtue, you are not dealing with E here after all. ILya |
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Gunshow75
Optics Apprentice Joined: December/23/2004 Location: Kentucky, USA Status: Offline Points: 209 |
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I'm sorry that I don't meet your expectations for being nice, for being polite. I really do read my posts before I hit send.
You can find what I do in my profile, and I still work. I am not now in an academic environment, but I was for the better part of 20 years. Being rude and obnoxious was not the norm. |
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Tom |
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tahqua
MODERATOR Have You Driven A Ford Lately? Joined: March/27/2006 Location: Michigan, USA Status: Offline Points: 9044 |
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ST, you put it all into terms a lot of us understand and that is exactly how it works for me. There is a ton of info here on this thread and it is a good one. I hope it continues. |
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Dogger
Optics Jedi Master Joined: January/02/2007 Location: Ontario, Canada Status: Offline Points: 8921 |
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I have PM'd both opticsmike and Gunshow on different topics and they are both very helpful friendly guys. I think we're aiming for the same end but with differing views on how to get there. I really appreciate the effort that OM has put into this and if the end product can be made better by input from Gunshow and Ilya well that's even better.
Like tahqua I hope the dialogue can continue in a positive light. Don't need hurt feelings or egos getting in the way - we are all friends here! Let us know if/how we can help.
Craig
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God save the Empire!
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koshkin
MODERATOR Dark Lord of Optics Joined: June/15/2004 Location: United States Status: Offline Points: 13182 |
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Just as an addendum, I never said that people have to be nice, just polite.
Heck, if I claimed that we all have to be nice here, I would have to go back and erase 90% of my own posts. ILya |
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opticsmike
Optics Apprentice Joined: September/09/2008 Location: Amherst, NY Status: Offline Points: 185 |
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In all actuality, the calculator is very simple. Unfortunately the discussions kept getting off on tangents that kept making it more confusing than it needs to be, and the tone has been even more distracting. I will definitely write up a white paper that explains it in clear terms and I look forward to answering questions and working with like-minded people to make this an easy to understand and beneficial tool. Keep in mind that the usefulness is limited to providing an idea of how much a certain scope configuration will perform over another of the same optical quality, but it is much more useful than anything else we have. The usefulness could of course become pretty amazing if a standard measuring method was utilized for light transmission, resolution, and maybe even contrast. But even then, scopes can vary in optical quality among even the same exact model. But right now as it stands, supertool73's model is much more accurate for anyone wishing to compare scopes among different brands, or better yet, reading the helpful information from eveyone here and asking questions. The white paper will outline four steps to the calculation that must be understood progressively: 1. Theoretical Light Gain that the scope delivers to the eye pupil. 2. Realistic Light Gain that the scope delivers to the eye pupil. 3. Conversion of Realistic Light Gain to a brightness scale that human beings can relate to. 4. Overall Low Light Performance as a combination of human-perceived light gain and resolution gain. After writing the white paper, I will modify it to better suit it's ability to answer questions as they come. I also hope that once it is thoroughly understood, some useful contributions could be made by others. Thanks for your support everyone. I look forward to doing everything I can to provide something that is truly useful. Believe me I have much better things to be doing if I didn't believe it to be possible for this to become useful for everyone. |
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koshkin
MODERATOR Dark Lord of Optics Joined: June/15/2004 Location: United States Status: Offline Points: 13182 |
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Excellent. Please post you write-up when you are done with it.
I have three reviews I need to finish before I can spend any real time on this, so I won't get to dig through this fro a little bit. ILya |
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cheaptrick
MODERATOR Joined: September/27/2004 Location: South Carolina Status: Offline Points: 20844 |
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WHAT...NO MORE MISSION?!?!?
See ya'll back at the NCO club!! Drinks are on Optics Mike and Gunshow
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Gunshow75
Optics Apprentice Joined: December/23/2004 Location: Kentucky, USA Status: Offline Points: 209 |
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"...To gunshow75, if you disagree with someone, try to do it in a nice way. ... Out in the real world, politeness is a virtue, you are not dealing with E here after all." I took those comments to mean that I wasn't being nice, or polite. |
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Tom |
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