|
|
Joined: Oct 2010
Posts: 1,364
Campfire Regular
|
Campfire Regular
Joined: Oct 2010
Posts: 1,364 |
I had a pair of Pentax 8x56s that were quite impressive in low light situations.
Heavy enough that a tripod was more useful for overcoming fatigue than the shakes at 8x
Not phase corrected, so they weren’t optically competitive, but No complaints mechanically.
History May Not Repeat, But it Rhymes.
|
|
|
|
|
Joined: Sep 2004
Posts: 29,383
Campfire Ranger
|
Campfire Ranger
Joined: Sep 2004
Posts: 29,383 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski?
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that?
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Sep 2004
Posts: 29,383
Campfire Ranger
|
|
Campfire Ranger
Joined: Sep 2004
Posts: 29,383 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference.
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. Hell No I'm not a sales person
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating.
Last edited by jwp475; 08/18/21.
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Sep 2004
Posts: 29,383
Campfire Ranger
|
|
Campfire Ranger
Joined: Sep 2004
Posts: 29,383 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating. I know what Twilight Factor is and how it is calculated. So the quoted twilight factor on the Tract binos is 16+ vs 29+ for the Swaros. Like I said before if it is not a misprint then why such a big difference?
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating. I know what Twilight Factor is and how it is calculated. So the quoted twilight factor on the Tract binos is 16+ vs 29+ for the Swaros. Like I said before if it is not a misprint then it is a big factor, especially when people buy these binos to spot game in LOW LIGHT. If you know what it is and how it's calculated then why the these 2 stupid posts? Why is their twilight factor 1/2 that of a 15x56 Swarovski? Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference.
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Sep 2004
Posts: 29,383
Campfire Ranger
|
|
Campfire Ranger
Joined: Sep 2004
Posts: 29,383 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating. I know what Twilight Factor is and how it is calculated. So the quoted twilight factor on the Tract binos is 16+ vs 29+ for the Swaros. Like I said before if it is not a misprint then it is a big factor, especially when people buy these binos to spot game in LOW LIGHT. If you know what it is and how it's calculated then why the these 2 stupid posts? Why is their twilight factor 1/2 that of a 15x56 Swarovski? Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. Are they not the same power range 15x56? Then using the calculation you provided that you googled they should be identical and they are not. Hint, one has way better coatings and well it should since it is double the price. The true test would be to tripod mount both binos in a lowlight setting where game can be spotted and lets see how much detail each provides.
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating. I know what Twilight Factor is and how it is calculated. So the quoted twilight factor on the Tract binos is 16+ vs 29+ for the Swaros. Like I said before if it is not a misprint then it is a big factor, especially when people buy these binos to spot game in LOW LIGHT. If you know what it is and how it's calculated then why the these 2 stupid posts? Why is their twilight factor 1/2 that of a 15x56 Swarovski? Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. Are they not the same power range 15x56? Then using the calculation you provided that you googled they should be identical and they are not. Hint, one has way better coatings and well it should since it is double the price. The true test would be to tripod mount both binos in a lowlight setting where game can be spotted and lets see how much detail each provides. Dumb szz they are identical since they are the same size and power. Twilight factor is nothing more than a calculation You claimed to know all of this. You're ab idiot
Last edited by jwp475; 08/18/21.
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Sep 2004
Posts: 29,383
Campfire Ranger
|
|
Campfire Ranger
Joined: Sep 2004
Posts: 29,383 |
How easily you resort to name calling when you lose an argument. Let me make it easy for you. Tract 15x56 specsSwarovski 15x56 specsSO I guess both these companies don't know how to calculate twilight factor eh? Putting you on ignore since you can't read a simple spec sheet. DOn't bother responding.
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
How easily you resort to name calling when you lose an argument. Let me make it easy for you. Tract 15x56 specsSwarovski 15x56 specsI SO I guess both these companies don't know how to calculate twilight factor eh? Putting you on ignore since you can't read a simple spec sheet. You dumb azz I haven't lost anything, you didn't read the information that I posted and you keep posting stupid crap I don't give a rats azx about what is on those sights. They can't calculate different and you would know that if you knew how it is calculated like you claimed The formula is in the information that I posted above. If you can do the math do it
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Aug 2005
Posts: 28,309 Likes: 21
Campfire Ranger
|
|
Campfire Ranger
Joined: Aug 2005
Posts: 28,309 Likes: 21 |
Why is their twilight factor 1/2 that of a 15x56 Swarovski? What makes you think that? Reading spec sheets from both binos. Are you a tract salesperson? 16.2 vs 29.9 you can google it . Hopefully it is a misprint because that is a good amount of difference. The twilight factor is the square root of the product of the diameter of the objective lens and the magnifying power of the binocular. [For example, an 8x32 binocular would have a twilight factor of 16, and a 10x42 would have a twilight factor of 20.5. However, in a modern binocular, performance in dim light depends more on the quality of the optical coatings than on the twilight factor formula. Good coatings can double the amount of light that gets through the binocular. If you pick up an old binocular from the 40s, or a cheap, low-quality binocular, you'll see very poor performance in dim light. Then look through a modern, top-quality binocular with the same magnification and lens size, and see how much brighter and clearer the image is, despite the fact that both binoculars have the same twilight factor rating. I know what Twilight Factor is and how it is calculated. So the quoted twilight factor on the Tract binos is 16+ vs 29+ for the Swaros. Like I said before if it is not a misprint then why such a big difference? Common sense should tell you there can't possibly be that much disparity between the two. The Tract's Schott UHD glass is exceptionally good and wouldn't allow that. If you put a Swaro SLC HD and a Toric 8x42 side by side on a tripod you'll see very small differences.....picking nits so to speak, and you'll have to look long and hard to pick 'em out. I'd bet $$$ the same is true for the 15's.
It is irrelevant what you think. What matters is the TRUTH.
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
28.9827 is the calculated twilight factor of a 15X56 binocular.
This calculation does not tell you of glass quality or lens coatings ability in low light. It is nothing but a calculation.
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Mar 2005
Posts: 824
Campfire Regular
|
|
Campfire Regular
Joined: Mar 2005
Posts: 824 |
If 29.827 is the calculated twilight factor of. 15x56 bio, and nothing but a calculation, then why aren't the twilight factors the same for the binos mentioned above?
Swarovski references the twilight factor according to ISO 14132-1. Does that ISO take into account optical coatings?
I realize we are comparing apples and oranges with respect to price of these two mentioned binos, but it also looks to me like we are also comparing apples to oranges on some vino performance too.
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
If 29.827 is the calculated twilight factor of. 15x56 bio, and nothing but a calculation, then why aren't the twilight factors the same for the binos mentioned above?
Swarovski references the twilight factor according to ISO 14132-1. Does that ISO take into account optical coatings?
I realize we are comparing apples and oranges with respect to price of these two mentioned binos, but it also looks to me like we are also comparing apples to oranges on some vino performance too. Read this and it will answer your question chrome-distiller://278a5b38-004c-4b03-81aa-893279349b92_808b216e6394e8df12b70a121a28b3f2722f5e15fdd79528a15fcec46c5b102b/?title=Optics+Myth+9+-+%22Twilight+factor%22+is+key+to+performance+in+dim+light&url=https%3A%2F%2Fwww.birdwatching.com%2Foptics%2Fmyths2006-9.html Short answer is that twilight factor is calculated and is the same for any binocular that has the same objective diameter and powet. Doesn't tell you anything about quality of glass or coatings
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
UPS delivered mine @ 9:27 PM
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
Joined: Aug 2006
Posts: 22,954 Likes: 21
Campfire Ranger
|
|
Campfire Ranger
Joined: Aug 2006
Posts: 22,954 Likes: 21 |
How's the after-dark performance.........?
|
|
|
|
|
Joined: Apr 2005
Posts: 30,998 Likes: 8
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Apr 2005
Posts: 30,998 Likes: 8 |
How's the after-dark performance.........? Looked very good. Give me a week or so and I'll know more.
I got banned on another web site for a debate that happened on this site. That's a first
|
|
|
|
|
603 members (21, 1beaver_shooter, 1eyedmule, 1badf350, 160user, 71 invisible),
3,908
guests, and
1,328
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums81
Topics1,194,759
Posts18,535,662
Members74,041
| |
Most Online11,491
Jul 7th, 2023
|
|
|
|
