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Should I go 7x (2 Viewers)
- Thread starter Torview
- Start date
When I purchased my 7x42 FLs they had the closest focus, widest FOV and lightest weight of all the ultra premium 7x42s.
FrankD
Well-known member
BruceH
Avatar: Harris Hawk
Sorry for the poor description.
My understanding is that a binocular with lens flatteners will have a larger center view relative to the total viewing space as compared to a similar classic design (no lens flatteners).
If the viewing situation is such that there is a large depth of field range which is close to equaling the total vertical viewing diameter, then some objects being viewed may actually fall outside the center view of a classic design, but will still be in the center view of a binocular with lens flatteners. If this is the case, then it seems a large center view would be a nice complement to the larger depth of field characteristic of a 7X, depending on the viewing situation. That is why I thought the EDG with its large center view makes for a nice choice with a 7X and its large depth of field.
Here is my attempt to illustrate what I am thinking for a specific viewing situation. I just downloaded the diagramming software and have not mastered the learning curve so the result could be better, but the idea is to show a general concept of how I think this works. The diagram is not precise or exactly to scale and it assumes a similar field of view for each binocular.
Hope that clarifies what I am trying to say. If it is correct, well that's another story!
Attachments
looksharp65
Well-known member
Thanks Bruce for your effort! You may know I'm a great fan of sketches like yours and I have posted quite a few on the forum myself.
When writing my previous reply, I tried to make a similar sketch but failed to make it comprehensible and beautiful.
Guess I must go back to the drawing board for a few hours of head-scratching:brains:
//L
When writing my previous reply, I tried to make a similar sketch but failed to make it comprehensible and beautiful.
Guess I must go back to the drawing board for a few hours of head-scratching:brains:
//L
eddy the eagle
Well-known member
Can anyone tell me why I would want to view a bird at the edge of the field of view?I always centre the bird I am viewing but maybe this is wrong.Of course when watching a flock of birds I concentrate on those in the centre and I am aware of the others and if I want too centre those as well.Can anyone explain please? Regards ...Eddy
BruceH
Avatar: Harris Hawk
Frank....Since you stated there are no current 7X alphas and then stated that you did not forget about the EDG 7X42 (which is a current model), I assume that means you do not consider the 7X42 EDG to be classified as an "Alpha" binocular. Is that correct? I know there are some members that feel the Nikon EDG line is not an "Alpha" for various reasons (mostly not related to optical quality), but I didn't think you shared that opinion based on your recent statement in another thread.
http://www.birdforum.net/showpost.php?p=2816758&postcount=61
(For those interested, here is a current thread to discuss the meaning of "Alpha".)
http://www.birdforum.net/showthread.php?t=265755
Have you had the opportunity to compare the 7X42 EDG and the 7X42 Zeiss FL side by side? I have never seen a Zeiss 7X FL so it would be interesting to hear how they compare.
I have compared the 7X42 EDG-II (which has a stated 419 ft FOV) with the Zen-Ray 7X36 ED2 (with a stated FOV of 477 ft). I was looking at numerous feeding dove and quail centered about 15 yards. I thought the difference in the FOV would be immediately noticeable based on the specs, but to me it was not. I could see it when looking for it but it was not readily apparent to me. It may be because at such a short viewing distance, the actual additional FOV is not much. I noticed I was doing much less repositioning of the EDG, most likely due to the large center view.
I obtained the 7X EDG primarily for early morning and late evening game spotting and also for close up viewing of flocks of birds. Maybe the additional field of view would be more significant to me if I were doing more distant viewing with the 7X.
BruceH
Avatar: Harris Hawk
To me it is bird (singular) vs. birds (plural).
Sometimes I am interested in looking at a single bird (or other game animal) so I can study the detail such as the color or feather pattern. In that case I would want to center the bird. Other times I enjoy viewing the whole flock simultaneously so I can watch the interaction and the dynamics taking place.
Every morning and evening I have about 70 or more dove and quail out back and I will just center the view in the middle of the flock, then sit back and enjoy. It is like watching a movie on the big screen. It is so much easier and enjoyable to take it all in without having to consistently reposition the binocular. The 7X large depth of field and a large center view are great in that application for me.
BruceH
Avatar: Harris Hawk
"One picture is worth a thousand words."
I am looking forward to what you have to say or show, whatever may be the case!
eddy the eagle
Well-known member
Thank you Bruce for your quick reply.I possibly do this without knowing and I will check next time I get a large flock on the ground.Regards ..Eddy
looksharp65
Well-known member
As promised, this sketch is my attempt to visualise what happens when looking through two pairs of binoculars: one with curvature of field and the other with a flat field.
Unfortunately them don't seem to show much, or maybe nothing, and certainly not the opinion I was trying to assert.
The upper image shows that a binocular with positive field curvature will allow objects closer to the observer to be in focus while focused to a farther distance.
But it does also show that the upper edge of the FOV will be more out of focus than the flat-field binocular.
The lower image consequently shows that the flat-field binocular has a shallower depth of field in the lower part of the image (closer to the observer), but that the upper (more distant) part of the FOV will be more in focus than the binocular with positive field curvature.
Everything will change when the binoculars are refocused. If the flat-field binocular is focused to a slightly closer distance than the other, the differences of depth of field should decrease or disappear.
But my sketch is not necessarily representative to birding at ground level since pointing them down so much that the horizon is close to the upper edge of the FOV means that you look at a quite close distance. If birding from an elevated position, things will be different.
My objection to your post would still be valid provided that the binoculars are pointed straight forward so the horizon will be somewhere near the middle of the FOV.
Then it's mostly sky and distant birds above the horizon so the curvature of field will not noticeably blur any object near the upper edge of the FOV, simply because it's empty.
The positive curvature of field will benefit the sharpness of objects on the ground, located closer to the lower edge of the FOV.
As a whole, I prefer a total edge sharpness with 10x binoculars over curvature of field.
Although I instinctively center the bird I want to see in the center of the FOV and stare fixedly on it, the flat field indeed gives a significant impression of greater sharpness.
It seems that I can detect a decreased sharpness even outside my macular region despite the very low VA we all have there.
Edge sharpness is very nice, but it has to come with the other desirable optical attributes.
//L
PS. I don't wish to put much emphasis on the sketch, but it might hopefully provide some food for thought.
Unfortunately them don't seem to show much, or maybe nothing, and certainly not the opinion I was trying to assert.
The upper image shows that a binocular with positive field curvature will allow objects closer to the observer to be in focus while focused to a farther distance.
But it does also show that the upper edge of the FOV will be more out of focus than the flat-field binocular.
The lower image consequently shows that the flat-field binocular has a shallower depth of field in the lower part of the image (closer to the observer), but that the upper (more distant) part of the FOV will be more in focus than the binocular with positive field curvature.
Everything will change when the binoculars are refocused. If the flat-field binocular is focused to a slightly closer distance than the other, the differences of depth of field should decrease or disappear.
But my sketch is not necessarily representative to birding at ground level since pointing them down so much that the horizon is close to the upper edge of the FOV means that you look at a quite close distance. If birding from an elevated position, things will be different.
My objection to your post would still be valid provided that the binoculars are pointed straight forward so the horizon will be somewhere near the middle of the FOV.
Then it's mostly sky and distant birds above the horizon so the curvature of field will not noticeably blur any object near the upper edge of the FOV, simply because it's empty.
The positive curvature of field will benefit the sharpness of objects on the ground, located closer to the lower edge of the FOV.
As a whole, I prefer a total edge sharpness with 10x binoculars over curvature of field.
Although I instinctively center the bird I want to see in the center of the FOV and stare fixedly on it, the flat field indeed gives a significant impression of greater sharpness.
It seems that I can detect a decreased sharpness even outside my macular region despite the very low VA we all have there.
Edge sharpness is very nice, but it has to come with the other desirable optical attributes.
//L
PS. I don't wish to put much emphasis on the sketch, but it might hopefully provide some food for thought.
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The 7X42 EDG is most certainly a first-letter-of-the-greek-alphabet binocular. I think it's the best 7X you can buy.
Personally, edge sharpness is more about being distracted than actually studying birds (or other objects) in the periphery. Soft edges are usually not problematic when looking skyward (e.g. hawkwatching), but they often intrude on the terrestrial view where objects are visible across the field of view. In the 10-50 foot range, soft edges can be downright annoying.
My aversion to soft edges grew with age, something I attribute to an ever decreasing ability to accommodate. I parted company with a Leica Ultravid as a result. My SE and SV have good edges...problem solved.
Personally, edge sharpness is more about being distracted than actually studying birds (or other objects) in the periphery. Soft edges are usually not problematic when looking skyward (e.g. hawkwatching), but they often intrude on the terrestrial view where objects are visible across the field of view. In the 10-50 foot range, soft edges can be downright annoying.
My aversion to soft edges grew with age, something I attribute to an ever decreasing ability to accommodate. I parted company with a Leica Ultravid as a result. My SE and SV have good edges...problem solved.
What about the Fujinon.
http://www.eagleoptics.com/binoculars/fujinon/fujinon-polaris-7x50-fmt-sx-binocular
http://www.eagleoptics.com/binoculars/fujinon/fujinon-polaris-7x50-fmt-sx-binocular
Three plus pounds of binocular. Yep, that will be popular in birding circles.
Yes, HaHa that is why I sold mine BUT it did have good optics. More for astro use.
Torview
Well-known member
Took a chance on the Opticron Bga Se 7x42 Uttings are doing at just £219, the Bga line is a fine range although I`v never tried the 7x42 !
With Winter`s dismal light levels around the corner and an ever lessening choice of 7`s around I thought it was too good an offer to ignore.
Should be here tomorrow.
With Winter`s dismal light levels around the corner and an ever lessening choice of 7`s around I thought it was too good an offer to ignore.
Should be here tomorrow.
I've been agonising over the purchase of a used 7x42FL, wondering if I can justify a 7x of that value (or any another binocular for that matter). The Imagic range are good quality units, at this price, and as you say, the dwindling availability of 7x roofs, this appears to be a great choice. Got one ordered too. Thanks for the heads-up.
Edit: Incidentally, this past weekend, I visited a camera/optics shop in a nearby city. They had a range of Opticrons and Swaros in the window. I went in and asked if I could try the Opticron 7x42. The assistant/shop owner asked why I wanted anything 7x, then told me that 8x was what I needed. I'm sure he was "helping" me, but I didn't get to look through them, so wasn't tempted to buy them. Perhaps this bargain was waiting for me/us? (I hope he wasn't right. though......)
Dave
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NDhunter
Experienced observer
Dave:
The salesman was right, as he does not stock 7X.
There seems to be some that like the 7X size, and they may have some advantages, if you are a short distance user and can appreciate the easier view and brighter image.
Otherwise the obvious choice is 8x42, a great all around size. In most
cases you will not notice much difference.
I am not sure about what other binoculars you are using but if looking at
the FL, the 8x42 is a great all around choice.
Jerry
You may be right, Jerry.
A used 7x42FL is a considerable outlay for something that might not suit me in the long run. I do like the easy view of my 7x36 Excursions and find them more useful in a woodland/closer environment, they are spoiled by CA though and could be a little sharper.
I hope that it's not just the wide FOV that I am attracted to.
Dave
A used 7x42FL is a considerable outlay for something that might not suit me in the long run. I do like the easy view of my 7x36 Excursions and find them more useful in a woodland/closer environment, they are spoiled by CA though and could be a little sharper.
I hope that it's not just the wide FOV that I am attracted to.
Dave
black crow
Well-known member
Just speaking of power, 7x suits be better than anything else. I always seem to gravitate to my 7x bins even if I prefer the optics, fit and feel of my other bins. I have 6x, 7x, 8x,9x and 10x.
