ME 1.7x Converter - Image Quality (1 Viewer)

[biowizard]

Does anyone hereabouts have the Swaro ME 1.7x converter for their ATX/STX scope, especially on the 95mm or even 115mm models? I'd be interested in any comments about it? While I assume that like any teleconverter, there is a loss of brightness equal to the square of the magnification ratio, here about 3-fold (1.7^2 = 2.89), I'm particularly interested in the sharpness of the resulting image. Does it stretch the image beyond the resolving power of the main scope?
ME 1.7x

 

[Tringa45]

Does it stretch the image beyond the resolving power of the main scope?

No, the potential resolution is determined by the objective diameter. With excellent examples this would be 1,2 arcseconds for the 95 mm and 1,0 arcseconds for the 115 mm scope.
At maximum magnification with the extender the exit pupils would be a mere 0,8 mm or 1,0 mm respectively. The image would be dim and lacking in contrast and if your eyesight is average or better it would convey little or no more information than at 70x.
Added to that, getting on the bird at a minimum magnification of 50x is going to be rather difficult.

John

 

[DRodrigues]

It works great both with the X95 and X115. It's one of my preferred solutions for high power viewing Preferred CR-telescopes and the one I use more frequently - now with a X115 - still didn't updated the page...
There is a light decrease but the resulting image quality still is excellent.
It's a must have for those that do high distances birding and/or enjoy high magnifications!

 

[Will K]

I have heard that the booster does not change the AFOV, either, since this spec is determined by the eyepiece alone. Is this confirmed?

 

[DRodrigues]

I have heard that the booster does not change the AFOV, either, since this spec is determined by the eyepiece alone. Is this confirmed?

Yes, the Swaro extender doesn't affect the AFOV.

 

[kabsetz]

David,

Have you found a good sample of the X115 now?

 

[DRodrigues]

David,

Have you found a good sample of the X115 now?

Hi Kimmo,
I know someone that has a ATX115 in Portugal but we still didn't managed met to compare samples...
Hopefully will do it during the next months and I will finally write a X95/X115 text...
You still didn't found a significantly better X115 than yours X95?

 

[tenex]

Added to that, getting on the bird at a minimum magnification of 50x is going to be rather difficult.

Actually, at the distances involved in our use of higher magnification, this is not a problem. It's just a question of getting on the general vicinity of the bird(s) to hope to see any details. Of course one may just be trying to deny that sometimes they're just too far away, if that's what you were thinking...

 

[kabsetz]

David,

I've seen samples that resolve better than my ATX, but not by as much as they should. As I'm used to a very low aberration view, I don't want to swap scopes unless it has that. I haven't been looking that actively lately, but in the spring I might try to see a few more.

 

[grackle314]

Does anyone hereabouts have the Swaro ME 1.7x converter for their ATX/STX scope, especially on the 95mm or even 115mm models? I'd be interested in any comments about it? While I assume that like any teleconverter, there is a loss of brightness equal to the square of the magnification ratio, here about 3-fold (1.7^2 = 2.89), I'm particularly interested in the sharpness of the resulting image. Does it stretch the image beyond the resolving power of the main scope?
ME 1.7x

BTX 115 with and without 1.7x photos attached here. Photos taken using Samsung Note 9 attached to left eyepiece via Swarovski phone attachment. Photos were taken 20 minutes apart with phone camera settings unchanged and at normal phone camera resolution and magnification. Biggest effect for me on using the 1.7x is the ability to see details on birds at greater distances. The photos shown are for fixed location to compare with and without the extender. I was watching a pair of female common goldeneyes feeding and moving about in the pond and thought a comparison was better on a fixed location than following the birds.

 

[Brummie]

I've found one ME doesn't noticeably degrade the image quality. Two do.

 

[Will K]

I've found one ME doesn't noticeably degrade the image quality. Two do.

You mean you can stack several extenders together and exponentially increase the magnification to infinity? - In theory?

 

[Brummie]

You mean you can stack several extenders together and exponentially increase the magnification to infinity? - In theory?

Yes. And then you can strap your binoculars to the end, and take the magnification to 8 x ♾️

 

[Will K]

Yes. And then you can strap your binoculars to the end, and take the magnification to 8 x ♾️

Wow. I'd love to see some examples of the image quality and light deterioration this causes, however.

 

[Binastro]

You would need an infinity of extenders.

And an infinity of Earths to contain them.

The limitation is that light doesn't allow this.

Regards,
B.

 

[wllmspd]

Quicker to tape some kitchen foil to the end of the objective…. I pointed a 8x pair of binoculars into the eyepiece of a 10x many years back… things were close up, but very dull and dim. You can have too much of a good thing.

Peter

 

[DRodrigues]

I've found one ME doesn't noticeably degrade the image quality. Two do.

I agree.
I tried to use 2 extenders but there was no gain in resolution and isn't an issue with light loss - I tested on the moon at night and didn't gained resolution either with 2 extenders. So not an option for astro-users that want to go higher than 120x...
On the other hand, one extender result on higher resolutions and I use it for resighting nasal saddled ducks at >220m!

 

[Coloradodipper]

I got my 1.7X for my ATX95 today, seems good so far. It has been cloudy, cool and rain/snow on and off so not the most contrast laden of scene's but I did manage to get a good view of a Lewis's Woodpecker before he flew off. Obviously the laws of optical physics apply to this combo so even though the details hold up, it does get quite a bit darker and less contrasty as one ramps up the power. Hitting focus at 100X+ is more delicate too so some patience is logically required. I can imagine on those super clear, cold and crisp Winter days, this is going to be a great combo to view our local eagle's nest up the road.

I'll see if Saturn and Jupiter can emerge from the clouds tonight and are not swimming in bad seeing. The scope did outstanding on those on its own a couple nights ago which is partly why decided to buy this converter.

 

[Will K]

I'm considering getting the 1.8x extender for my Leica APO Televid. I'm curious to see how dark that gets in comparison with the Swarovski. The Leica is only 82mm, so it'll probably be rather noticeable. I expect that a ATX 115mm objective would be most forgiving for brightness retention.

 

[WCA]

The 1.7x extender reach/resolution is good enough for colour ring reading at 500m+ on species like Osprey even in significant heat haze, therefore making it an essential piece of kit for me.