8X or 7X for Forest birding (1 Viewer)

[mannukiddo]

Hello all,

I have been recommended a 7X42 or even a 6x for forest birding in India. Now I have the following questions that I hope some of you can answer:

1) How big is the difference in magnification between a 8X and a 7X roof. Is the difference big enough so as to stick to an 8X even though a 7x would possibly be better at finding birds.

2) If I choose the 7X then does it mean that now I have a bin exclusively for forests and warblers in bushes kind of birding or can it be satisfactorily be used for long distance raptor watching and wetland/shore/river bed birding. This is especially important to me as I may not carry 2 bins with me all the time.

Thanks in advance.

Regards

Mayur

 

[PYRTLE]

A x7 will give you a larger exit pupil (dependant on objective lens size) and generally therefore a "brighter " image than a x8, eg a 7x42 = 6mm exit pupil whilst a 8x42 is 5.25mm.

For forest birding a brighter bino' is probably desired whilst for observation of raptors, particularly in the air, a x 10 would be better.

All this points to the overall scenario in that for all round bird or wildlife observation an 8 x 42 is likely to be the best compromise. Obviously, there is a difference between the magnifications but only you will be able to judge how much this means to you.

 

[Tero]

8x with the maximum wide field would be OK. You do not have to go to 50mm for most uses.

 

[ceasar]

The 7 x 42 can be quite addictive after you use one a while. You really don't use the focus wheel as often as with others. I have a quality 7 x 42 with a 420' FOV and an inexpensive 8 x 42 with the same FOV that I keep as a "car" binocular. You really can see the difference between their DOF's.

The 7 x 42 is also quite good on raptors, especially if they are rather close and fast flying. 2 days ago, off my deck, a Turkey Vulture was swooping and sailing in the wind, coming close to my house and then out back and around again, sometimes at treetop height and sometimes below. I had trouble following it with my Nikon 10 x 32's but no trouble at all when I switched to my Leica 7 x 42 Trinovid.
Bob

 

[Steve C]

One of my all time favorite binoculars is a 7x36. Personally, I can not see enough size difference in the image size for me to really prefer 7x or 8x. However, that gets into some strictly personal preferences, which only you can really answer. That 7x36 would probably be the binocular I'd keep if some draconian thing happened and I could only have one. That is due to the image brightness, the very good resolution and the very deep field of view. It is a very easy on the eyes binocular, and its small size makes it easy to pack. Further its 5+mm exit pupil is a nice feature.

 

[Kevin Purcell]

A x7 will give you a larger exit pupil (dependant on objective lens size) and generally therefore a "brighter " image than a x8, eg a 7x42 = 6mm exit pupil whilst a 8x42 is 5.25mm.

It will only be brighter if your eye's entrance pupil is larger ot the same size of the exit pupil. If it's not that light doesn't make it into your eye.

This is an old astro bin rule of thumb which doesn't apply in daytime most of the time. At twilight and at night (once the eye gets big enough) it makes a difference.

Compare a exit pupil 4mm 8x32mm and 6mm exit pupil 7x42 during the day and the difference you see is the difference in transmission of the bin not the extra aperture. For about 30 minutes in temperate twilight it makes a difference.

Even in "forests" (whose forest! Dense European pine forest in winter are dark as are rain forests but most aren't that dark) in daytime your most eyes won't be that large but people vary. You can measure this with a camera with a flash (no red eye ... that's what you are trying to measure!) and a ruler in the light conditions you experience.

The main reason to bird with lower magnification in denser forests is larger depth of field especially when closer to the targets (again "forest" encompasses a range of densities and heights: rainforest to open oak forest to redwoods). For canopy birds not so much. For ground and low level birds especially the cryptic ones in bushes it helps a lot.

I think an older reason was also to improve field of view: as the birds get closer maximizing the FOV does help. But 8x bins often come with a very wide FOV these days so that advantage is less than it was (though it's still there in bins like the Zeiss 7x42).

Ultimately in comes down to forest density and where you are looking. Darker and denser forests do better with lower mag bins.

Two things help target ID with bins: magnification and transmission. THis goes to Steve's point "brighter" i.e. higher transmission bins really help especially when going for lower magnifications.

I think so ideal choices might be small FMC porros (that are not that common) or roofs with dielectric prisms. The Zeiss 7x42 of course is a standout here. I also have the Swift Eaglet 7x36 that Steve has and it is bright. A cheap solution in dimmer forests (with no too much stray light) would be the Leupold Yosemite.

I'm never too sure hwo much of the 7x or 8x makes a difference. It makes a small actual difference but I think sometimes I feel perhaps I'd see it better with 8x (though I probably wouldn't). And with a 10x ... well maybe I'd see it better but I wouldn't have found it.

I know Central and South American naturalists use a bin + a scope for this (even in the forest). Find the bird then positively ID it (in this case read colored rings for specific bird ID). So that's another thing to keep in mind (and another thing to carry!).

 

[John M Robinson]

Hello all,

I have been recommended a 7X42 or even a 6x for forest birding in India. Now I have the following questions that I hope some of you can answer:

1) How big is the difference in magnification between a 8X and a 7X roof. Is the difference big enough so as to stick to an 8X even though a 7x would possibly be better at finding birds.

2) If I choose the 7X then does it mean that now I have a bin exclusively for forests and warblers in bushes kind of birding or can it be satisfactorily be used for long distance raptor watching and wetland/shore/river bed birding. This is especially important to me as I may not carry 2 bins with me all the time.

Thanks in advance.

Regards

Mayur

It's funny you ask, as just last week a guy I only know through a forum like this one, sent me his brand new 7x42 Ultravid BR to compare to my 8x42 BRs. I love the 7x42, but to be honest it was very close to my 8x42. Almost equal view and I honestly couldn't see the power difference, it was more a slight FOV difference and a slightly easier view through the 7x42s. Put it this way, up until now I was really wanting a 7x42 to compliment and fill a gap between my 6x30s, 8x32, 8x42 and 10x42 bins. Now I see the 7x42 is so close to my 8x42 that I don't feel that need anymore. But, if this guy offered to trade me his 7x42 for my 8x42 Ultravids, there is a 60-40 chance that I would go for that trade. No way would I sell my bins at a loss to buy the 7x42s. I don't know if this is helpful or confusing.

John

 

[oleaf]

Mayur,

A good 7x is a great format for an all around binocular.

Excellent depth of field
Excellent, forgiving eye relief and comfortable view
Large FOV
More forgiving if hands shake... more stable
Brighter

Best all around binocular!

Cheers

 

[falcondude]

I use 8x (ZEN ED) and 8.5x (EL) in the woods quite often. I don't feel they lack anything since the field of views are probably the widest already. The exit pupils are sufficient even in the heavy growth area.

 

[Kevin Conville]

A good 7x is a great format for an all around binocular.

Excellent depth of field
Excellent, forgiving eye relief and comfortable view
Large FOV
More forgiving if hands shake... more stable
Brighter

Best all around binocular!

+1

The main reason to bird with lower magnification in denser forests is larger depth of field especially when closer to the targets (again "forest" encompasses a range of densities and heights: rainforest to open oak forest to redwoods). For canopy birds not so much. For ground and low level birds especially the cryptic ones in bushes it helps a lot.

I think that's the main advantage as well.

 

[Kevin Purcell]

I use 8x (ZEN ED) and 8.5x (EL) in the woods quite often. I don't feel they lack anything since the field of views are probably the widest already. The exit pupils are sufficient even in the heavy growth area.

Though for the Zen Ray ED and the other Chinese ED the wide FOV and brightness is excellent but the slow focus rate especially at close range makes them less than ideal for this use. They still work but with a faster focus they would be a lot better.

Large FOV doesn't always come with low magnification. The Eaglet 7x36 is an example of this and the Canon 7x42 too both have FOVs less then a few of my 8x bins. Even the Yosemite 6x30 has a FOV about the same as say the Diamondback 8x42. You might expect it to be huge but not so.

Large FOV with lower magnification used to be a given (in Olden Times! BW ... Before Waterproofing ) when eyepiece designs were a bit more constrained. With a fixed AFOV then dropping the magnification increased the FOV. But no some much any more with > 400 feet (>7.5 degree) FOVs even 420 FOV (8.0 degree) are not uncommon in 8x bins though I suspect if more companies made more 7x bins we might see more 450 feet FOV (that could be used with eyeglasses) like the Zeiss 7x42.

The same goes for larger ER with lower magnification. Again eyepiece designs were simpler. Higher magnifications needed shorter focal length EP which came with shorter ER. Again this constraint is not true. You can make an 8x with plenty of ER for even the most Coke Bottle Aviator glasses user.

So it comes down to the other reasons: DOF and shake. And the user's preference.

Ultimately I don't find a huge difference, really. I'm using both 7x and 8x a lot recently but 8x seems to be the best general purpose bin. But if I was spending a lot of time in the forest I'd probably go 7x. Perhaps more full days out I might go 7x too. If I was taking a scope (especially a compact 50mm scope) then I'd perhaps go with a 7x bin. If I had a lightweight Chinese ED 7x36 I think I'd be even more happy!

I tried 10x porro today after a lot of time using 7x roofs ... the shake took a bit of time to get used to but I think I finally calmed down and improved the grip.

One adapts! It's all a compromise.

 

[mannukiddo]

OK!! So I guess it more of a personal preference thing. Well I don't have the luxury of trying out both powers and returning the one that comes second best so I guess I will play safe and get a 8X and have the best of both worlds. The Zen Ray 8X43 suddenly looks very tempting.

Regards,

Mayur

 

[Kevin Purcell]

Just beware the slow close focus rate on the Chinese EDs. For forest work that's their biggest downside.

What sort of forest are you birding in? What sort of tree and canopy density? Is the understory clear or filled in?

 

[mannukiddo]

Just beware the slow close focus rate on the Chinese EDs. For forest work that's their biggest downside.

What sort of forest are you birding in? What sort of tree and canopy density? Is the understory clear or filled in?

Most of the times I bird at wetlands, sea and river shores which are close to my house and at least twice or thrice a month in moist deciduous forests a short distance away. These forests are quite dense in winters and in the monsoon but do lose a lot of their cover in summer. But most of the winter visitors are gone by then.
Besides this I regularly visit Tiger reserves like Ranthambhore (dry deciduous) and Kanha (moist deciduous but a very dense due to Sal and Bamboo). The Tiger reserves are only 4X4 or Elephant safari (only Kanha) affairs. Hiking and foot safaris are not allowed. Here animals like tigers, leopards, wild dogs, bears, wild boars, deer, monkeys and reptiles like snakes, crocodiles etc are easily seen besides the brilliant bird life. Most of the times guides that you hire here are keen only to show the stars of the show i.e the tigers and the leopards and are not really bothered to show the birds. One cant really blame them coz that's what most of the people come here to see, so you are mostly forced to look for yourself. My last visit at Kanha, in an hours drive, yielded at least 6 owl species and at least 7 eagle/hawk/buzzard species without much effort. I am sure there would have been many more sightings had the guide co operated.

So I guess fast focus is very much desirable in such scenarios. What are your recommendations then?

Regards,

Mayur

 

[Paskman]

Mayur

Looking at your rainforest requirements; you need a pair of binoculars that is tough, totally reliable, waterproof, wide-angle and bright. Tough, totally reliable and waterproof would usually mean a good quality roof prism. By default the wide-angle and bright would have to mean that it be of fairly low magnification i.e. 7X and at least 42mm objectives. You could look at 8X but I think that the negligible increase in magnification would be more than offset by the increase in brightness. If, however, brightness is less of a concern then a good wideangle 8X30/2 might fit the bill, this would also have the advantage of being lighter and handlier to use. I would say that ideally you need an alpha 7X42: Perhaps you could stretch to an SLC or find something second hand? Whatever you do get the best you can afford - if you don't, and have an interest in binoculars, you will only want something better, end up buying a more expensive pair and spending more in the long run. From what I can see this forum is populated by people who have ended up with large binocular collections and empty wallets through perpetually upgrading!!

Paul

 

[Steve C]

I don't know how hard they are to get in India, but I would take a look at a Swift Eaglet in either 7x36 or 8x42. The 7x is perhaps a bit narrow in fov, but the focus rate is fast, particularly close in to keep up with anything a human nervous system can be reasonably expected to follow.

 

[Kevin Conville]

Looking at your rainforest requirements; you need a pair of binoculars that is tough, totally reliable, waterproof, wide-angle and bright. Tough, totally reliable and waterproof would usually mean a good quality roof prism.

I would say that ideally you need an alpha 7X42: Perhaps you could stretch to an SLC or find something second hand? Whatever you do get the best you can afford - if you don't, and have an interest in binoculars, you will only want something better, end up buying a more expensive pair and spending more in the long run. From what I can see this forum is populated by people who have ended up with large binocular collections and empty wallets through perpetually upgrading!!

Sounds like good advice to me.
A Swaro SLC or Leica Trinovid would be great, a Leica Ultravid would be ideal IMO. Swaro doesn't make an EL in 7x and I (personally) don't care much for Zeiss' build quality on their FLs.

Buying a premium set of bins and enjoying them for decades seems the economical and most gratifying way to go.

 

[Steve C]

Mayur

From what I can see this forum is populated by people who have ended up with large binocular collections and empty wallets through perpetually upgrading!!

Paul

I think I might resemble that remark! However, I do not keep everything I use and comment on, nor do I necessarily buy it new. If I keep something and comment regularly on it it is because I find it worthy of keeping. I've got a few minor collectible binoculars, and few I keep for sentimental reasons. But there are maybe five I use a lot. I think I can cover a lot more situations with the five I have, which can all be purchased brand new for less money than the price of one alpha. If I kept everything, I would be broke.

As far as perpetual upgrading, look how anxious some seem to be about the new supposedly true flat field Swarovski. Seems like the current EL is plenty flat enough. So the try as many as you can, and keep up with the best technology is not limited to non alpha fanciers.

You are right about the alpha 7x though. The Meopta is about the least expensive really good full size 7x out there.

 

[Paskman]

I think I might resemble that remark! However, I do not keep everything I use and comment on, nor do I necessarily buy it new. If I keep something and comment regularly on it it is because I find it worthy of keeping. I've got a few minor collectible binoculars, and few I keep for sentimental reasons. But there are maybe five I use a lot. I think I can cover a lot more situations with the five I have, which can all be purchased brand new for less money than the price of one alpha. If I kept everything, I would be broke.

As far as perpetual upgrading, look how anxious some seem to be about the new supposedly true flat field Swarovski. Seems like the current EL is plenty flat enough. So the try as many as you can, and keep up with the best technology is not limited to non alpha fanciers.

You are right about the alpha 7x though. The Meopta is about the least expensive really good full size 7x out there.

I am slightly guilty myself! However I am glad that I bought some top quality bins a few years ago - everytime I consider "upgrading them" I always consider whether there would be any real gain for the money and so far the conclusion has been no. However with the new Alpha's coming out the question is becoming Hypothetical as I will never be able to afford the prices they are now asking. Mind you I still have a yearning for a pair of Nikon E2's or SE's!!

Paul

 

[FrankD]

FWIW I have used the 7x42 configuration almost exclusively for long distance raptor watching and have yet to be disappointed with it. At the moment I am going to go with one of two 8x42/43 models for my spring raptor excursions but who knows what could happen between now and next fall.