Puzzled over Field of View on Nikon Eypieces

[bill lord]

I have a 25-75 zoom eyepiece for my ED 78 and reading many of the messages there seems to be a lot in favour of the 30w eyepiece, the reason being given is the wide Fov. Now having been out to Southport birding yesterday I can understand that a wider field of view would be preferable in some instances, but I'm puzzled as to just how much difference the fixed eyepiece would make. Nikon say that my eyepiece has a Fov of 28m at 1000m, and the 30x eyepiece has a fov of 42m at 1000m. Does this 14m increase at this distance make a lot of difference. My inference would be that at 100m I would be looking at something which is just over a metre more than I can see at the moment. Have I got something wrong?

[Jay Turberville]

I have a 25-75 zoom eyepiece for my ED 78 and reading many of the messages there seems to be a lot in favour of the 30w eyepiece, the reason being given is the wide Fov. Now having been out to Southport birding yesterday I can understand that a wider field of view would be preferable in some instances, but I'm puzzled as to just how much difference the fixed eyepiece would make. Nikon say that my eyepiece has a Fov of 28m at 1000m, and the 30x eyepiece has a fov of 42m at 1000m. Does this 14m increase at this distance make a lot of difference. My inference would be that at 100m I would be looking at something which is just over a metre more than I can see at the moment. Have I got something wrong?

That sounds right to me.

The wider view gives you a 50% greater AFOV in this case. This means the area of the circle you are seeing with the wider view is about double the area the narrower view. It is my opinion that this extra viewing area adds tremendously to the experience of viewing through the scope. I find that psychologically it puts me out into the area that I am viewing. I consider the main benefit of a wider view is that it is provides a more pleasurable viewing experience.

[christineredgate]

So,Jay,is the 30x Wide better on the whole for digiscoping than the 20x60 Zoom.

[Jay Turberville]

So,Jay,is the 30x Wide better on the whole for digiscoping than the 20x60 Zoom.

Assuming you are talking specifically about the Swarovski eyepieces ...

For my CP5000, I believe the 30xSW would be better than the 20-60x zoom. But I haven't tried using one yet so this is based on the specs. The DCA adapter is not designed for the 30xSW either (though I have a workaround that makes it usable on the 20xSW and I assume I can use the same scheme on the 30xSW.)

The 30xSW should give a useful digiscoping range on the lower end of the spectrum. Something that I think is important. The more I digiscope and view the efforts of others, the more I think that people often push the optics too far. But this assumes that you are trying to take very good, sharp, high quality pictures. If your aim is to simply take pictures for ID purposes, then the nod goes to the 20-60x zoom for its high magnification.

If I were shooting with a CP4500 or CP995, I'm pretty sure I'd also want the 30xSW over the 20-60x zoom. The 4x lens on the CP4500 will give a lot of high magnification (not as much as the 20-60x). Enough for you to create nice and soft images. :) But it will also give you excellent low magnification performance. I like having the ability to get down to the low digiscoping ranges. Aside from delivering great quality, its nice to have the option when the bird is very close.

If I were shooting with a CP990, I'm not so sure. The 990 only has a 3X zoom. So I'd have to be pretty committed to not using any magnification much more than 3000mm equivalent. This isn't a problem for me, but many people want to push past that limit.

For other makes of eyepieces and cameras the benefits might change. And if you combine viewing with digiscoping, then your preference in a viewing eyepiece would be important to consider as well. Such considerations can make all the difference in the final choice.

[bill lord]

That sounds right to me.

The wider view gives you a 50% greater AFOV in this case. This means the area of the circle you are seeing with the wider view is about double the area the narrower view. It is my opinion that this extra viewing area adds tremendously to the experience of viewing through the scope. I find that psychologically it puts me out into the area that I am viewing. I consider the main benefit of a wider view is that it is provides a more pleasurable viewing experience.

Thanks Jay I should have thought to compare the area seen and realised that it would be greater than twice the area I am seeing. I will have a look through one of the 30x eyepieces the next time I visit Martin Mere and In Focus. It will have to wait a while though till I buy one I need to pay for what I've just aquired before I spend any more. ;)

[Ragna]

Jay I have been led to believe that the Swaro 30sw matches perfectly with their digiscoping adapter,I was told this by a Swarovski rep at the Rutland bird fair.

[Jay Turberville]

Jay I have been led to believe that the Swaro 30sw matches perfectly with their digiscoping adapter,I was told this by a Swarovski rep at the Rutland bird fair.

The 30xSW has a narrowed upper barrel very similar to that of the 20xSW. The 20-60x has the same diameter top and bottom. The issues are is that the DCA isn't stabilized by the upper part of the eyepiece barrel and that the tapered bottom portion doesn't provide a stable attachment unless something is done to stabilize the upper part. I haven't tried the 30xSW, but I have tried the 20xSW and this is definitely an issue. Though, as I mentioned it can be overcome.

The Swarovski web page does say that the adapter is for all of their eyepieces. But I've tried it on the 20xSW and this just isn't so. At least not without some extra fiddling.

[dogfish]

The Swarovski DCA fits perfectly on my ATS 30 wide. I believe the 20w is of a slightly different construction.

Sean

[scampo]

That sounds right to me.

The wider view gives you a 50% greater AFOV in this case. This means the area of the circle you are seeing with the wider view is about double the area the narrower view. It is my opinion that this extra viewing area adds tremendously to the experience of viewing through the scope. I find that psychologically it puts me out into the area that I am viewing. I consider the main benefit of a wider view is that it is provides a more pleasurable viewing experience.
The Nikon zoom is not so narrow beyond the minimum magnification, though, Bill (and don't forget this is 25x, not 20x).

I was looking at our local "mega" recently - a red-rumped swallow - with a 30x wide fixed eyepiece. I found the bird easily, but the sheer frustration of many around me with zoom eyepieces (not just with Nikon zooms, of course!) was obvious and it became clear that there are occasions when locating a bird is obviously far easier with a wide angle eyepiece. That said - a zoom is ideal when watching birds such as waders.

The one zoom eyepiece that puts all the rest to shame is the new Zeiss 20-60x - it allows you to see an area almost half as large again as even the Leica or Swaro zooms.

[Jay Turberville]

The Swarovski DCA fits perfectly on my ATS 30 wide. I believe the 20w is of a slightly different construction.
Sean

Then I guess the base of the 30xSW must be a bit larger in diameter than the 20xSW. On the 20xSW, the base diameter is about 1.5mm smaller than the diamete of the DCA where it clamps to the eyepiece. So when clamped, the eyepiece is not centered. The top portion of the eyepiece is about 5mm smaller in diameter and when clamped, the 20xSW gets clearly skewed to one side. My workaround is to wrap non-adhesive grip tape around the top of the eyepiece barrel until the diameter of the tape is nearly the same as the diameter of the adapter at that location. This keeps the eypiece centered and stable.

The 30xSW clearly has the same tapered shape, but if its base is an extra millimeter or so larger, then I guess that may be all that is needed to get a nice solid and center fit.

I'm curious about what camera you use. If it is a Coolpix, how does it work with the wider zoom settings?

[bill lord]

[QUOTE=scampo]The Nikon zoom is not so narrow beyond the minimum magnification, though, Bill (and don't forget this is 25x, not 20x).

I was looking at our local "mega" recently - a red-rumped swallow - with a 30x wide fixed eyepiece. I found the bird easily, but the sheer frustration of many around me with zoom eyepieces (not just with Nikon zooms, of course!) was obvious and it became clear that there are occasions when locating a bird is obviously far easier with a wide angle eyepiece. That said - a zoom is ideal when watching birds such as waders.

QUOTE]

I understand what you mean, I had trouble on Sturday finding a Water Rail at Mere sands Wood that was on a feeder about 20 yds in front of the hide. I shall have a look at the 30w eyepiece the next time I am in In Focus and perhaps save up for one. I think my chancellor might get a bit uppity if I spend any more at the moment. ;)

[dogfish]

I'm curious about what camera you use. If it is a Coolpix, how does it work with the wider zoom settings?[/QUOTE]

I do have a Coolpix 4500 but haven't used it with the new scope yet. Just checked the fit etc was OK when I bought the DCA. Will keep you posted when I take some shots.


Sean

[scampo]

[QUOTE=scampo] I think my chancellor might get a bit uppity if I spend any more at the moment. ;)
I am in the same position - but once you look through the scope with that eyepiece, you'll want it!

A friend with a Swaro + zoom had difficulty locating that swallow, too and when he looked through a nearby Swaro + 30x he was sold. Zooms are good but still limited. The only zoom that offers a wide view is the new Zeiss, really.

[Jay Turberville]

A friend with a Swaro + zoom had difficulty locating that swallow, too and when he looked through a nearby Swaro + 30x he was sold. Zooms are good but still limited. The only zoom that offers a wide view is the new Zeiss, really.

With the ATS80HD, I think one of the main culprits is the little sight tube. I found it nearly useless. I mounted an inexpensive Red Dot sight to the sight tube that is quite good at helping you get on a bird quickly. What the ATS80HD really needs (and perhaps other scopes could use it too) is a solid mount to accomodate different sighting aids.

Though I still very much prefer the view through a wide angle eyepiece. Its a better overall experience.

[scampo]

And, generally, the 60x view seems to show precious little more than a bright 30x.