Leica ASPH Zoom Question

[John]

The Baader VIP seems an obvious and clearly very strong contender. Others in the frame would be the Leica 1.8x extender unit, the Baader Zeiss barlow and the AP barcon I guess.

I feel that I will be using the ASPH zoom as a high magnification eyepiece often so the choice of barlow / extender is important. 

[Piero]

I don't think you can go wrong with any of those choices.  

Both the Baader VIP and the Baader Zeiss can be modified by adding spacers. In my opinion the VIP is more versatile because you can achieve 1.5x, 1.76x, and 2x natively, but you can still get factors between 2x and 3x with spacers as you can separately buy 7.5mm, 15mm, and 40mm rings. The varilock is also an option. 

The Baader Zeiss starts from 2x and can reach 4x in a similar way by adding spacers. 

Personally, I find more use cases within the 1.5x-2x (with options up to 3x if needed) than 2x-4x but this depends a lot on one's equipment. Cost difference is quite large too. 

It would be nice to have a review (under very good seeing conditions) between these two barlows ..  

[Highburymark]

4 hours ago, John said:

The Baader VIP seems an obvious and clearly very strong contender. Others in the frame would be the Leica 1.8x extender unit, the Baader Zeiss barlow and the AP barcon I guess.

I feel that I will be using the ASPH zoom as a high magnification eyepiece often so the choice of barlow / extender is important. 

It may be that the 1.8x extender isn't quite powerful enough for you John - it gives me up to 150x in the Tak 100DC. Or it will deliver about 180x tops in your 100DL. Above 150x I use Nagler 3.5 or Nagler 3-6 zoom. 

[John]

Anybody tried the newer Astro Physics Advanced Barlow (BARADV) with the Leica ASPH zoom ?

 

[Stu]

Whilst I would agree that the VIP is more flexible at the lower multiples, and that the x1.8 extended looks (and I'm sure is optically) a lovely piece of kit, I suspect John may find that x2 and above is useful. Of course the VIP still plays nicely in this space so remains a strong contender.

x2.5 gives 3.5mm to 7.1mm which I used to find very useful, often 3.5mm is above my max for local seeing conditions at x207 in my Tak so gives plenty of range. I used a x2.5 PowerMate for this quite often and you can get a Televue T2 adaptor for the PM to give a secure connection.

John, I know you have a 2 to 4mm Nag Zoom so may find that even higher multiples are useful but they do tend to get a little unwieldy with the extension tubes needed.

Regarding the AP BARADV, I can comment on the BARCON which I use with my Herschel Wedge and Binoviewers. As you probably know I use 25mm Zeiss Eyepieces, and with extension tubes often use the BARCON at x4 in addition to a GPC when seeing conditions allow to give me over x200 and the results are stunning. In my experience I believe the AP is every bit as good as the Zeiss Abbe Barlow at these higher multiples.

So there are three very strong contenders, it's a hard choice. I do think the VIP is a very flexible system though. Sometimes the AP being 2" can be a disadvantage if you want a compact travel kit with say a T2 Zeiss Prism rather than a full 2" diagonal.

Enough of my rambling  

[Piero]

Super comment Stu!

Very interesting thread this one!    

[John]

Very helpful "rambling" if you ask me Stu, thanks

[Piero]

@Stu 

Oh man..! why did you post your last comment?!  

Now I am thinking that I might also need a 3x - 4x with my zoom!    

[John]

With my scopes, I reckon 2x would be the most useful amplification and possibly 2.5x on occasions.

I keep looking at the Baader / Zeiss 2x barlow. Don't know why ........ something about the "Z" word I guess

 

 

[Piero]

  Any update?   

[John]

Well the ASPH zoom has arrived and looks very nice. The clouds look not so nice so 1st light was a conifer top about 100 metres away - which looked green

With the 2" APM adapter the point of focus seemed around 5mm further inwards than the 21mm Ethos was when used in my F/6.5 Vixen frac. Should be fine in all my scopes in that mode at least.

A barlow that does not require further inward focuser movement would be nice, if there is one

Otherwise it's waiting for a clear night time ...... AKA the new kit curse

 

[Pig]

Mine has been sat patiently in the diagonal for some time now..... the clouds have very stubborn indeed of late in this neck of the Woods.

It is a good job I have my ? as I wouldn't have left the house for some time now ? Work aside of course.

[John]

Actually getting some glimpses of astro stuff with the zoom now, in between lots of clouds but could not resist getting the ED120 out.

So far, rather nice. Saturn at 101x - quite a few moons and nice detail even at the relatively small image scale. Zooming is fun - watch that sky darken !

[Piero]

It is fun indeed! 

and very comfortable too!

[Piero]

After months of thoughts, I've decided to make a few changes to my 1.25" light equipment .. These include a new Baader/Zeiss Barlow which is coming tomorrow.   

If you can wait, I can let you know how it performs against the Baader VIP (weather permitting ). 

[John]

Your views on how the two compare will be very interesting Piero

From the reading I've done it seems that the Zeiss "advantage" shows at higher amplification factors , eg: 3x, 4x etc. But your findings may well be different....

[Piero]

As far as I understand, the 40mm spacer will give 2.6x with the Baader/Zeiss. I have that spacer, but it's in Italy at the moment.

So, what I can do is: 

- VIP 2x vs BZ 2x 

- VIP 2x vs BZ 2x before the diagonal which should change them to about 3x 

I'm also particularly curious to know whether the BZ is parfocal or close. There are rumours that it is at 2x. I can also try the BZ with 30mm spacer (the two 15mm spacers coming with the VIP). 

My bet is that these two barlows will be close. That's what I hope at least! If so, the VIP will be used with my big zoom, whereas the BZ with the docter and small 1.25" eps. 

[John]

I've another query on the Leica ASPH zoom if I may,

Where is the focal plane of the eyepiece ?

With the APM 2" adapter fitted, the eyepiece required around 5mm further inwards travel than my Ethos 21 does.

I've seen on figure of ~20mm above the "shoulder" of the eyepiece (where the 2" barrel ends) when the 2" adapter is fitted but that sounds a little much. Based on the comparison with the Ethos 21 I'd guess around 14mm-15mm above the shoulder but thats only based on 1 comparison.

If anyone can help on this, thanks

[Piero]

Do you need this to know how much extra distance the zoom adds to the barlow? Just curious!  

[John]

30 minutes ago, Piero said:

Do you need this to know how much extra distance the zoom adds to the barlow? Just curious!  

Something along those lines, yes.

I've found a very useful post by YKSE on another forum which I think helps answer my question though.

 

[John]

Update on the Leica ASPH zoom:

I've had a few sessions with the eyepiece and also the Baader VIP zoom. I am very, very impressed with the performance of the eyepiece in the 4 scopes that I've used it (3 refractors and the 12" dob). The VIP barlow also works very well indeed. The only issue I found with the Zoom + VIP combo is that there is some astigmatism in the outer 25% of the field when the amplification factor is 1.75x or less. At 2x this is much, much less apparent being very slight in the F/5.3 dob and not visible in the F/6.5 and F/9 refractors.

The much discussed edge of field brightening effect (EFoB) has only been apparent on 1 occasion and that was with the eyepiece unbarlowed, in the F/6.5 refractor and viewing an area of the sky close to the horizon where there is quite a bit of light pollution. I looked for it at other times including moving fainter object to the edge of the field of view but EFoB was not an issue then. I suspect it is connected to particular lighting conditions ?

The planetary performance of the barlowed eyepiece has been outstanding - I could see any differences between the barlowed zoom and my Pentax XW eyepieces apart from the slightly smaller FoV at the longt focal length (9mm barlowed at 2x) and a larger than XW FoV at 4.5x. The ability to zoom seamlessly between these focal lenghts is immensely satisfying and the range covers all the useful hig and very high magnifications that I use with my 12" dob and all but the really high ones that I use with my F/9 refractors.

So lots of positive notes so far. But now for the not so positive

My example of the eyepiece was bought used but appears to be in mint condition. There are no signs of wear anywhere on it and it came with all the original packaging and reciepts from the previous owner, who bought it new.

This is just as well because when observing illuminated backgrounds at low power I've noticed dozens of tiny dark marks or spots, right across the FoV. These were only apparent when I observed the moons surface and the illumination filled the field of view. They went out of focus as I zoomed in and I'd not seen them when observing point sources, nebulous objects and Saturn presumably because the chances of one of these spots co-inciding with the small bright object were very slim. Nevertheless these specks were definitely there. I checked the external eye and fiel lens surfaces but these were as clean as a whistle. The contanimation must be on one of the internal lens surfaces - not accessible to me because the zoom is sealed against moisture ingress and still under warranty (thank goodness !).

Google threw up a few of mentions of this issue:

https://www.cloudynights.com/topic/433969-leica-asph-zoom-specks-inside/

https://www.cloudynights.com/topic/462790-leica-zoom-issue-maybe/

https://www.cloudynights.com/topic/565329-dust-inside-leica-asph-zoom/

The 3rd link above describes the issue that I have almost exactly

OK. Having discussed this with the previous owner of the eyepiece (who was very helpful but had not noticed the issue) we have agreed that I should contact Leica to see what their solution is, given that the eyepiece is still under warranty. Within 12 hours Leica UK have provided me with full instructions on how to return the eyepiece for a service, a pre-paid UPS delivery chit plus details of my local UPS agent and I have a personal contact point within their service department (in Portugal !) where the eyepiece is now headed to be checked and serviced.

So, understandably, mixed feelings at the current time from myself. These eyepieces cost £600+ new so quality control should be pretty darn good. Issues are clearly still slipping though so Leica need to do better on that front. On their response to the problem, thus far at least, I can't fault them. The test will be how things progress once they have examined the eyepiece of course. I'll report back in due course ......

 

 

 

 

[GavStar]

John

Can you see the small specks just by looking at the eyepiece or do you have actually use it at low power to see the speck against the moon etc?

Gavin

[John]

57 minutes ago, GavStar said:

John

Can you see the small specks just by looking at the eyepiece or do you have actually use it at low power to see the speck against the moon etc?

Gavin

You can see them looking through just the eyepiece (no scope) on the 25x setting but you need to either look at a pretty bright light source or look into the eye lens at a slightly oblique angle. If you move your head around while looking through the eye lens, if they are there, you will pick them up. They look a little like tiny bubbles but could be specks of dust or tiny spots of fluid of some sort. They tend to go out of focus and disappear when the eyepiece is "zoomed".

When I 1st noticed them I thought they might be a sort of reflection of a texture on the internal wall of the eyepiece tube but having observed the moon now it's clear that they are on one of the optical surfaces. They don't rotate when you zoom the eyepiece but it's quite possible that no optical elements are rotated during that operation anyway. 

 

 

[Stu]

John, sorry to hear about this.  I experienced exactly the same thing with an eyepiece which I evaluated before buying it secondhand, eventually deciding not to proceed with the sale.

Leica service is very good so I do hope the sort the problem out for you.

[John]

11 minutes ago, Stu said:

John, sorry to hear about this.  I experienced exactly the same thing with an eyepiece which I evaluated before buying it secondhand, eventually deciding not to proceed with the sale.

Leica service is very good so I do hope the sort the problem out for you.

Thanks Stu.

Was the eyepiece that you tried one of the Leica ASPH's too ?