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Review: Tract Toric 8x42 (1 Viewer)

Trevor,

I am always interested, as a wearer of spectacles, on the eye relief measurement according to ISO theoretical and as measured, and from the eye cups in their fully down position, axial lay to the the eye; also the diameter of the eye cup.

These data will assist most potential users to assess the likelihood of a binocular suiting their needs with regard to eye relief etc.

Oops..further measurement would be useful, the depth of the eye cup from the rim to the ocular glass.
 
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Trevor,

I am always interested, as a wearer of spectacles, on the eye relief measurement according to ISO theoretical and as measured, and from the eye cups in their fully down position, axial lay to the the eye; also the diameter of the eye cup.

These data will assist most potential users to assess the likelihood of a binocular suiting their needs with regard to eye relief etc.

Oops..further measurement would be useful, the depth of the eye cup from the rim to the ocular glass.


My apologies on the delay of the reply. Truly a thank you for the feedback as we look to communities like this to better assist any user of optics. Its all too often that specifications that should be included fall behind. I'll make sure this gets passed along accordingly.

Thanks again!

Trevor
TRACT Optics
 
Pretty simple actually. I place a white cloth measuring tape across a wall. I then measure off 30 feet from that wall. Place the center of a tripod at the 30' mark. Mount the binocular to the tripod. Focus on the tape and adjust until the tape is centered in the horizontal center of the field. Place the edge of the tape just at the edge of the left side of the view. Read how many inches are visible on the right side. With my Toric I can read 48 and a half inches. Convert that to feet, in this case 4.04' which is at 10 yards. Move the decimal left two places and you have 404' at 1,000 yards.

Don't try to read too much tape. With most binoculars the fov measured like this is within a couple of feet of the specification.

As I understand using an 8X bin at 30' would be equivalent to the naked eye/corrective lens at 3.75'/3' 9". It would seem to me for accuracy sake that the reviewer would determine the furthest away that they could distinguish the marks on the tape then multiply that by the power of bin.

I looked at an old yellow Stanley 25' tape, tinted w/rust, determining that my maximum distinction in reading the 1/16" markers was around 7'.[6.5' easy 7 is a strain] Evah so roughly w/8x bin I would need to be close to 60' to duplicate my maximum recognition length.

What I wonder is how much fov would be effected from Dublin. :smoke: It would seem that your useable fov would increase if you were twice as close as needed to read the tape.

Is it possible that could account for some of your wider fov readings? If any difference, should you double the length, wouldn't the fov be narrower?

Whaddya think?

ETA: I can appreciate the convenience of 30'/3000'/1000yds moving the decimal one spot left. Doubling the length to 60' would also be easy enough to convert though w/perhaps improved accuracy.

You are using an 8x at 30' that in essence is 16X/double the power/half the distance thus allowing for extra magnification und better fov readings it would seem. I cannot say by how much, but surely measurable, eh?

ETA II: If we use 20/20 as a standard then moving up to 10' reading the bottom line on the Snellen chart does not make us 20/10 though we see what we couldn't at 20'. I'm not saying the fov changes from 30' to 60' at 8X. It just strikes me that you are reading the tape measure w/8X glass at 30' instead of 60'. I'm curious if you read that tape w/8X bin at 60' the same as you do at 30'.

I do not know how many feet w/8X would be the equivalent of reading the Snellen chart at 20' w/20/20 vision in relation to your tape measure. I have an IOL in me right eye w/mild cataract in the left, so I guesstamate the 60' based on my tape measure. Off the cuff I would think that somewhat in the ballpark.
 
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Nixterdemus, Is the basis of your argument that it is more accurate to measure 3000' with a 60' ruler than a 30' one? Or that a calculated fov error induced by magnification above or below 8x could be reduced by measuring 'less'? Or maybe both. I had trouble following your reasoning, but that's what I get out of your comments.
Obviously Steve is assuming that the magnification is as stated when measuring the FOV.

Bill
 
Yes I am assuming the magnification is as stated. I also assume there is some sort of give and take in the stated fov specs. I do not assume that a binocular listed as an 8.2* fov will show every single specimen as smack on 8.2*. I measure the distance to the center of the tripod as I have found that small measuring differences have no significant effect on the observed measurement. I further assume a couple of tenths difference in magnification will not be a big deal either. I do not even try to pick nits here. If a binocular is stated with a 420' fov and I get say 415-425', then my stance is that the glass is at its specified fov spec. This may not be purely correct in technical parlance, but the average user will not be able to see that in use. However when the stated spec is 377' and the measured fov is 420, I check the distance to be sure I didn't mess up. Seems to me that is enough to be considered off the mark and noticeable in use. There is a particular floor tile that measures exactly 30' from the wall with the tape. So I check to be sure I'm in the correct spot. I also double check the measurement. I always do it several times anyway.

I do not take into account the curvature of the earth, the changing day lengths, distance from the equator, season of the year, make of the tape, the color of the tape, or meteorological changes involved in the coming storm system, Just the distance from the tape to the center of the tripod and how many inches or centimetres can be read from one side to the other.

What I do find odd is that in a conversation with a company rep of one of the understated fov binoculars in this review was that the engineers told him that the only way to measure the fov was at 1,000 yards or meters. At this point I do not buy that. I can check at 1,000 laser measured yards or out to a surveyed mile if needed. The fov measurements are just made more difficult and they don't change a blasted thing. Seems to me that an engineer ought to know if his designed fov is 8.2 degrees or whether it is something different. I always figured fov was a design based parameter.

The explanation I get that at least makes some sense (although I don't agree here either) is that the consumer won't complain if there is more fov than stated. My disagreement stems from the fact that if the OEM wants to use a company to sell stuff, or a company wants to use an OEM for the same thing, a properly stated fov spec, particularly when wider than it is, is a selling point.
 
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I wonder how much, when reading a tape, the fov might change if the person looking through the bins is giving himself a 2X advantage compared to 20/20 vision w/Snellen chart at 20.

The gist is Steve determines the fov at 30' from the tape using an 8X bin. His conclusion is formed after determining the two points where he can no longer read the tape on each side. My point is instead of being twice as close to the tape as needed to read that perhaps if he calculated his maximum distance to read unassisted and then converted that distance to correspond to the 8X the fov might not be as wide.

Sort of the same as using a magnifying glass vs unassisted. Perhaps the perception would change. You are still looking through 8X you just haven't scooted up half the distance to the goal. Just a thought.
 
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Nixterdemus,

One last time. I measure all fov sizes of all magnifications at 30 feet. I do this because it is 10 yards and a very simple matter to convert the inches of tape viewable to feet, then move the decimal place. The fov measures like this does not change when double checked at a laser ranged 1,000 yards. Since that is the case, I'll stick to 30'.

If you get half as close to the tape, you get half of the numbers visible. If you get twice as far away, you get twice the numbers visible. If you look at the tape through a 10x glass the numbers look bigger. If you use 6x, the numbers look smaller. The fov and magnification are constants for a given binocular. An 8* field is an 8* field at any distance or magnification.
 
Fascinating Steve, allow me a few more indulgences.

"This one focuses to 7 feet as compared to the listed close focus distance of 8 feet."

On paper that's -12.5%. As magnification decreases minimum close focus decreases. Likewise a lower magnification would increase fov. What's the odds, eh?

"Viewing the tape there is obvious distortion around the outer inch. The black numbers on the white tape are clearly visible, but the 1/16" fractional markings are not separable."

So, combining both edges there's around 2" of the tape that you cannot distinguish the 1/16" marks. Are those two inches included in fov? If you adjusted the 30' distance to the tape to the distance you can read the tape unassisted X Magnification of bin used would you still see obvious distortion at only around an inch on the edges?

" However when the stated spec is 377' and the measured fov is 420 ..."

But the bin reviewed fov you determined to be 404'. Twenty-seven feet is quite a bit, +7.16%, though not nearly forty-three. Granted you merely offer an example, but you used the stated fov of 377' for the bin reviewed for half of the equation.

"The fov measures like this does not change when double checked at a laser ranged 1,000 yards."

Might that be you laser ranging 1,000yds against your measurement at 30'?

"If you get half as close to the tape, you get half of the numbers visible. If you get twice as far away, you get twice the numbers visible. If you look at the tape through a 10x glass the numbers look bigger. If you use 6x, the numbers look smaller. The fov and magnification are constants for a given binocular. An 8* field is an 8* field at any distance or magnification."

Yes, half as close makes for much easier reading of the tape than twice as far away. As I understand your fov method rests on reading the tape. The degrees/angle are constant though perception of useable fov can fluctuate amongst individuals. Perhaps Tract listed 377' fov as what they considered useable fov. If you subtract the 2" it's 46.5'/387.5.

How far from that tape can you distinguish the 1/16" marks w/o magnification? W/corrective lens should you require.

After determining fov do you ever double the fov of one barrel for comparison?

Would one barrel fov doubled equal both barrels combined fov?

When checking fov do you ever view w/right eye diagonally horizontally across the field stop of the left barrel or vice versa left eye/rght barrel? Do you see the same fov edge as when normally mounted for fov?

Bear w/me. I've previously stated that I can read 1/16" on a Stanley, 25' I think, tape at 7'. Therefore w/10X bin I should be able to read roughly the same at 70'. If I could only read at 64.75' that might be an indicator that the bin was closer to 9.25X/-.75X. Especially if combined w/shorter minimum focus & wider fov than stated.

Just a thought.
 
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Fascinating Steve, allow me a few more indulgences.
<snip>
Just a thought.

I think the underlying point that measuring magnification might be a useful
way of 'affirming' actual field of view at the stated power is reasonable, since Steve is comparing his own test results with manufacturer's specs, but it is also asking him to do more work, for which he is rewarded ever so handsomely on this forum ;-)

I just wanted to say thanks again to Steve for taking the time to do these tests and reviews. If you want to include a test for magnification, I won't complain, nor will I if you don't!

Bill
 
Nixterdemus,

You are evidently trying to make a mountain out of a molehill here or maybe you don't get what is going on. I stated that the magnification was 8x. I determined that by shining a light through the ocular and measuring the diameter of the light circle through the binocular. It was 42 mm and the exit pupil is 5.25 mm.

You are talking about resolution. It does not matter enough to matter if you or I or somebody else can read 1/16" on a yellow Stanley tape closer or further away than somebody else can. If a binocular has a specified fov of 8* or 420' at 1,000 yards you need to be able to see about 50.5 inches of tape. 50 inches is 417' and 51 inches is 425'. That last half inch is easy enough to see even if if the binocular is slightly out of focus, which due to edge distortions and field curvature, it probably will be. If the binocular falls close to those outer limits, my take, as I have stated previously, is close enough. Yes over the whole series of production runs there will be some sample variation in magnification as well as with fov. In my experience it is rare for one of these to get out of whack by over the design specified QC spread. Again I am not too concerned with a couple of tenths magnification or with a couple of tenths of fov variance.

How clearly the binocular reads the small gradations across the view of the tape is useful in determining size of sweet spot. Resolution is determined in the center field of the binocular.

You do have to strain or screw your eyes to actually getting a reading at the edge of the field. Typically the fov is the same with one barrel vs both. Yes there can be differences if specifications from onse side to the other. When two sides differ enough to exceed the ability of the users eye to accommodate there will be issues with apparrent focus and some eye strain or lack of depth of field.

Also if you have properly set the focus for the binocular it seems you are dealing with corrected vision.

It seems Steve Ingraham used some small spots on dollar bills to use for vision acuity, but he was talking about resolution in those reviews.

Also Nixterdemus please note the 8*/420 feet was just an example, not a reference to the fov I measured in the Toric. I suggest you can screw your eye balls around the fov all you want. This method has been discussed here in discussions of how to measure fov. It works for my purposes.

You do have to screw the eye somewhat to actually read the tape at the edge. There can be some issues with the two barrels differing too much from each other.
 
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Nixterdemus,

You are evidently trying to make a mountain out of a molehill here or maybe you don't get what is going on. I stated that the magnification was 8x. I determined that by shining a light through the ocular and measuring the diameter of the light circle through the binocular. It was 42 mm and the exit pupil is 5.25 mm.

You are talking about resolution. It does not matter enough to matter if you or I or somebody else can read 1/16" on a yellow Stanley tape closer or further away than somebody else can. If a binocular has a specified fov of 8* or 420' at 1,000 yards you need to be able to see about 50.5 inches of tape. 50 inches is 417' and 51 inches is 425'. That last half inch is easy enough to see even if if the binocular is slightly out of focus, which due to edge distortions and field curvature, it probably will be. If the binocular falls close to those outer limits, my take, as I have stated previously, is close enough. Yes over the whole series of production runs there will be some sample variation in magnification as well as with fov. In my experience it is rare for one of these to get out of whack by over the design specified QC spread. Again I am not too concerned with a couple of tenths magnification or with a couple of tenths of fov variance.

How clearly the binocular reads the small gradations across the view of the tape is useful in determining size of sweet spot. Resolution is determined in the center field of the binocular.

You do have to strain or screw your eyes to actually getting a reading at the edge of the field. Typically the fov is the same with one barrel vs both. Yes there can be differences if specifications from onse side to the other. When two sides differ enough to exceed the ability of the users eye to accommodate there will be issues with apparrent focus and some eye strain or lack of depth of field.

Also if you have properly set the focus for the binocular it seems you are dealing with corrected vision.

It seems Steve Ingraham used some small spots on dollar bills to use for vision acuity, but he was talking about resolution in those reviews.

Also Nixterdemus please note the 8*/420 feet was just an example, not a reference to the fov I measured in the Toric. I suggest you can screw your eye balls around the fov all you want. This method has been discussed here in discussions of how to measure fov. It works for my purposes.

You do have to screw the eye somewhat to actually read the tape at the edge. There can be some issues with the two barrels differing too much from each other.

Hi, Steve:

I think my next book will be—

BB Stacking for Fun and Profit.

Bill
 
Nixterdemus,

You are evidently trying to make a mountain out of a molehill here or maybe you don't get what is going on.

When curious I prefer going to the source & it is your review. I've formed no conclusions that indicated you erred.

I stated that the magnification was 8x. I determined that by shining a light through the ocular and measuring the diameter of the light circle through the binocular. It was 42 mm and the exit pupil is 5.25 mm.

I refer you to Henry's post #26 & 31.

You are talking about resolution.

Resolution, but at maximum distance w/o magnification X whatevah power should evah so roughly also be able to be resolved.

It does not matter enough to matter if you or I or somebody else can read 1/16" on a yellow Stanley tape closer or further away than somebody else can.

Out of context. I merely used a known quality, Stanley tape, at a specific maximum distance unaided view, not excluding corrective lens if required, X 10 due to example of a 10X bin.

If a binocular has a specified fov of 8* or 420' at 1,000 yards you need to be able to see about 50.5 inches of tape. 50 inches is 417' and 51 inches is 425'. That last half inch is easy enough to see even if if the binocular is slightly out of focus, which due to edge distortions and field curvature, it probably will be. If the binocular falls close to those outer limits, my take, as I have stated previously, is close enough. Yes over the whole series of production runs there will be some sample variation in magnification as well as with fov. In my experience it is rare for one of these to get out of whack by over the design specified QC spread. Again I am not too concerned with a couple of tenths magnification or with a couple of tenths of fov variance.

So, anything you can see whilst mounted to the bins is fov & if you cannot read the 1/16" you rely on 1/8" &/or perhaps a bit o' estimation. If the couple of tenths become a half or even more that would be significant.

How clearly the binocular reads the small gradations across the view of the tape is useful in determining size of sweet spot. Resolution is determined in the center field of the binocular.

You do have to strain or screw your eyes to actually getting a reading at the edge of the field. Typically the fov is the same with one barrel vs both. Yes there can be differences if specifications from ones side to the other. When two sides differ enough to exceed the ability of the users eye to accommodate there will be issues with apparent focus and some eye strain or lack of depth of field.

I don't know what I was thinking when I suggested that one barrel doubled would equal the bins fov. I was curious of possible extra fov from not forming a perfect circle w/both barrels. Plausible especially w/fat E.P.

Also if you have properly set the focus for the binocular it seems you are dealing with corrected vision.

It seems Steve Ingraham used some small spots on dollar bills to use for vision acuity, but he was talking about resolution in those reviews.

Also Nixterdemus please note the 8*/420 feet was just an example, not a reference to the fov I measured in the Toric.

Some folks require corrective lens to view through bins, but even if they do not the diopter adjustment w/focus could be considered corrected vision.
My use of 'corrected vision' is not of the latter.

I just found it peculiar that you referenced your example of 8*/420' w/377' of the listed spec for the reviewed bin instead of your 7.8*/404' determination.

I suggest you can screw your eye balls around the fov all you want.

That's a childish approach at best. I wondered if you stayed mounted looking to the sides for fov & if you could see more unmounted looking across the field stops.

I cannot hardly view at any deviation L-R w/o vision blacking out. Possibly if I backed away from the mount though I cannot stand not being buried in the eyecups. I can look sideways across the field stop unmounted one eyed for more fov & in one case the other day, at the same time, it brought the previously out of focus far edge into sharp focus. I could see fine detail of the small red berries that grow from an ivy type vine. I know what's up w/that, how 'bout you?

This method has been discussed here in discussions of how to measure fov. It works for my purposes.

You do have to screw the eye somewhat to actually read the tape at the edge. There can be some issues with the two barrels differing too much from each other.

I never speculated that you invented the method, nor do I doubt that it works accurately enough if indeed the magnification is as stated. You have no problem dismissing spec sheet fov/close focus, yet you do not question magnification to the point of testing.

Closer than spec minimum focus combined w/larger than spec fov would seem to suggest that perhaps the spec'd magnification is lagging a wee bit on the low side. Doesn't have to, but it could. Also, if lower than 8X it doesn't have to be to the point of 377'. Instead of the whole 27' it might only account for around half putting the bin at a very respectable 390'.

Because of blackouts when straying very much from center view wide fov means little to me. I can see fov w/peripheral though devoid of sharp detail. However, I note it seems to be a big item for birders in the lower, <12X, magnifications. The higher magnification, even if considered wide fov, are narrow enough for me to see the entire fov sharply.

Is it possible that bias for large fov prevents some from digging any deeper when they run across a much larger fov and/or significantly shorter miniumum focus than spec'd?

I enjoy reading your reviews. Not quite as much fun as analyzing various possibilities for the abundent fov. I love a good argument though do not care to argue.

JGRaider came up w/similar results. For whatevah reason the fov appears to hover around 400' suggesting a pattern in at least a sample of two.

Thanks for your replies I appreciate your explanations and the time it took to present them unto me.

I think my next book will be—

Hey swabbie how 'bout sharing that w/Cloudy Nights crew?

Oh, R-I-G-H-T

nevermind ...
 
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"Hey swabbie how 'bout sharing that w/Cloudy Nights crew?

Oh, R-I-G-H-T

nevermind ..."

I wanted to come back for some time. However, now that they have TWO know-nothing experts over there misleading the newbie and non-English speakers—who seem eager to lap up the male bovine excrement—it will probably never be. I can just bask in all the many good things said about my contributions before I started having my experience and credentials used to pump the ego of an inexperienced (except for reading) and non-credentialed wannabe—one who I asked more than once, KINDLY in PMs, to leave me alone.

I also take pleasure in that so many current and past moderators have bought my book and have said so many nice things about me.

As one moderator recently told a friend about the troll with the proven record of coming out of the woodwork at the mere mention of my name:

“___________ is not just a troll; he’s a very skillful troll.” This is, of course, why he gets away with shredding their terms of service when others are consistently censured for far less.

And when I was cast aside, a member-at-large said: “It looks like they threw out the baby and kept the bathwater.”

But, as I said in Vignette #28:

“One might think moderators would see what was going on and address the issue. But most forums are about head count to increase business revenue and not furthering knowledge of a hobby, craft, or science.”

See the signature, below; it had its origin there.:cat:

Bill
 
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What in the world is all this about?

We are arguing over a toy.

My GI Joe doll is better than your Army Pete! Oh YA! My Batmobile can run over your X Wing fighter.

Gents--relax and enjoy the view.

Coin Hound, methinks you joined a conversation that had been in progress for 12 years, and I can assure you if you had been in my shoes those 12 years you would have something more than a cavalier attitude. Just sayin'. And, what I said was FOR Nixterdemus and NOT AT him. I'm confident he understood that.:cat:

Bill
 
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No I have not been in your shoes for many years--so take time and educate me about this.

My original request was for an explanation of this thread.

Of course I'm sarcastic--enlighten me about the "history" of this thread.

I own a pair or Tracts--happen to be pretty good glass

I have no idea about the history of the thread. I was just making a comment about a comment Nixterdemus had made. Just be glad you're here. If you think you NEED to know what I was talking about, you should ask Steve C, Troubador, NDFarmer, Perterra, Mono, Arthur Checiny, or some of the PhDs who no longer go there, or do so very sparingly: Ed Huff, Holger Merlitz, Marco Ciacca, etc. :cat:

Bill
 
What in the world is all this about?

We are arguing over a toy.

My GI Joe doll is better than your Army Pete! Oh YA! My Batmobile can run over your X Wing fighter.

Gents--relax and enjoy the view.

That's irrational as we are discussing the same bin. As well I will argue a point(s), yet not stoop to arguing.

Is English your second language or have you always lacked basic comprehension skills and/or cognitive limitations?

Might you be a graduate of Trump University? 3:)
 
That's irrational as we are discussing the same bin. As well I will argue a point(s), yet not stoop to arguing.

Is English your second language or have you always lacked basic comprehension skills and/or cognitive limitations?

Might you be a graduate of Trump University? 3:)

OH Lord how that begs for a comment, leaving Trump out of the equation. :eek!: However, I'll be a good boy and let this foolishness lie. ;)
 
Hi, Steve:

I think my next book will be—

BB Stacking for Fun and Profit.

Bill

Bill,

Might be fun to try one at Stacking Odds in the Casino ;)

Looks to me like if you look at Dr Hawkings quote he is really saying there is no such thing as knowledge. If anybody ever gets to the point where they think they know all about it they will find that light at the end of the tunnel is attached to a train. How many times has the impossible been done by somebody who did not take no for an answer. However much is learned simply represents the tip of the iceberg.
 
Bill,

Might be fun to try one at Stacking Odds in the Casino ;)

Looks to me like if you look at Dr Hawkings quote he is really saying there is no such thing as knowledge. If anybody ever gets to the point where they think they know all about it they will find that light at the end of the tunnel is attached to a train. How many times has the impossible been done by somebody who did not take no for an answer. However much is learned simply represents the tip of the iceberg.

"Too often an education goes to the head and not to the mind."—Bill Cook

Each new generation of scientists proves the last generation of scientists to be foolish. College is a place where pebbles are polished and diamonds are dimmed. :cat:

Bill
 
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