Another wide angled EP, but would it be worth it

[bomberbaz]

SW Aero 40mm?

According to their respective figures the Aero is 68 fov and the Swan 70. TFOV 136 and 140 respectively in my C8 Nexstar. Anyway like I said, I shall hang fire, I have spent far too much time looking into this now than to just brush it off and buy one of the afore mentioned EP's although the Aero is favourite if the Vixen doesn't stand up to scrutiny.

[John]

The UK Vixen rep is a member here so perhaps he will chip in on this at some point. I agree that there is an issue if the eyepiece has one thing printed on it but the actual spec is markedly different. When field stop sizes and true fields of view are measured with calipers and drift timings I have seen variations from specs noted by reviewers of other eyepieces but not usually on this scale or with a reputable brand such as Vixen.

I reckon there could be some variation between claimed and actual with a number of the eyepieces discussed in this thread to be honest.

I've owned the 30mm and 40mm Aero ED's and they are very nice eyepieces, lightweight too, for large 2" eyepieces.

[michael.h.f.wilkinson]

The Aero is reported as a TMB Paragon clone, so it should have a field stop of 45.7mm, which shows it has a geometric or true AFOV of 68 deg, compared to a 69 deg AFOV (the difference is half a degree of pincushion distortion at the edge. The SWAN is reported to have a 46mm field stop as measured here:

http://www.cloudynig...uments/swan.pdf

Not much in it. The rating in that review (in an F/10 SCT) is rather lower than what I would give the Paragon. If the Aero is a clone it should be better than the WO, especially at the edges of the FOV. The review above states that the inner 75% of the FOV are usable. I found the entire FOV of the Paragon usable, even in an F/6 scope. The inner 90% of the FOV was really sharp, the outer 10% being ever so slightly fuzzy (corrected by refocusing so field curvature rather than astigmatism). My review is here:

I have seen one citation (which I cannot track down now) of a 47mm field stop diameter for the LVW 42mm, which I think was corroborated by drift testing by Mr. Spock. The review of the EP on FLO (by one Andrew) states that the apparent FOV is clearly larger than 70 deg.

[bomberbaz]

Could do to see the twst resulta by mr spock. I have not written off the EP and FLO have it waiting for me. I just want definative ansrews to specifications. I do not think that is unreasonable.

Steve

[bomberbaz]

Response I received from Vixen, read bottom to top. I also sent them the picture from this thread showing the quoted fov at 72.

From: Brian Deis

Sent: Thursday, April 11, 2013 9:33 PM

To:

Cc: Janet Deis

Subject: Re: Vixen LVW FOV

Japan confirms it is 65 degrees.

From: Stephen

Date: Thursday, April 11, 2013 10:01 AM

To: Brian Deis <info@vixenoptics.com>

Subject: Re: Vixen LVW FOV

Hello Brian, have you any news regarding this please

Regards, steve

Sent from Stephen

On 10 Apr 2013, at 23:25, Brian Deis <info@vixenoptics.com> wrote:

Stephen,

I agree. I think it was a typo on the e.p. But am checking with Japan to clarify. Our catalogue says 65 degree.

From:

Stephen

Date:

Wednesday, April 10, 2013 3:14 PM

To:

Brian Deis <

info@vixenoptics.com

>

Subject:

Re: Vixen LVW FOV

Ok Brian but then why does this picture of the EP show the 72 to left of the big 42mm. Its all rather confusing!!

Best Regards,

Stephen

From:

Brian Deis

Sent:

Wednesday, April 10, 2013 10:50 PM

To:

Subject:

Re: Vixen LVW FOV

Stephen,

We had the wrong FOCV and changed it to 65.

Clear Skies,

Brian

From:

Stephen

Date:

Wednesday, April 10, 2013 2:41 PM

To:

<

support@vixenoptics.com

>

Subject:

Vixen LVW FOV

Hello there Vixen.

I am interested in buying one of your products, namely the LVW 42mm eyepiece. However I have some conflicting information. Several websites from UK disributers are quoting a FOV of 72 for the EP as was your own website until yesterday, now it is quoting 65. Please can you advise the exact FOV for this EP to clarify the position.

I think you in advance for your assistance in this matter.

Best Regards,

Stephen

[bomberbaz]

Cant find details of mr spock drift test, only a comparison between a radian and Viven NLV ep. Dam this is taking over my life..................

[Stargazer_00]

That's alarming. What a faux pas! I wonder if they have any legal liability for the products they're already sold

[John]

Interesting Cloudynights thread here dating from 2006 and there were doubts being expressed back then:

http://www.cloudynig...0/o/all/fpart/1

The review that one of the posts in the above thread links to reports that the true field of the Vixen looks larger than the 65 degrees of the Pentax 40mm XL that it's being compared to in daytime testing.

If the eyepiece does not deliver the FoV stated it would certainly not be the first eyepiece where this has been the case. This does not make it OK of course but there have been others - I think the Hyperion 24mm might fall into that category, or maybe it's the 21mm ?

[Stargazer_00]

the Vixen has been banded around for some time as the king of TFOV. I wonder how many sales have been attributed to this reputation. I don't currently own anything by Vixen and I doubt now I ever will, certainly not anything that has a claim to some degree of performance that others are lacking in.

[E621Keith]

Cant find details of mr spock drift test, only a comparison between a radian and Viven NLV ep. Dam this is taking over my life..................

You can send Mr Spock a PM. It will probably be than waiting for my results. I can't test until the weather clears, that may be tonight or I may have to wait weeks before I get clear sky.

[John]

In a post in this thread:

http://stargazerslou...t/#entry1378987

Mr Spock says that he can just fit the Pleiades cluster into the FoV of the Vixen NLVW 42mm when it's used with his Celestron 9.25 SCT. I reckon you need a true field of around 1.2 degrees to do that so his 42mm must have an apparent FoV of something like 70 degrees to give that true field with that scope.

[Moonshane]

surely if the Vixen is £300, you'd be better with a used 41mm Panoptic for the same money?

[alan potts]

I know it don't help you but where I was coming from about 3 months back when I brought this up . Televue always seem to srcew the last bit out of a design : UWA Norm 30mm, TV= 31mm SWA max 40mm Panoptic 41mm, same with the Ethos the others 20mm etc.

I was shocked to here that the Vixen was wider as I too had read the CN review a long time back and always thought it was a bit odd that the maths didn't add up with what was printed on sites. When I was shot to bits I just accepted the people that have them know better, not at all unreasonable on my part.

Alan

[Stargazer_00]

41mm Pan sure does sound like the max then. There just happens to be one for sale in Classifieds too if the OP is feeling flush

[John]

I was shocked to here that the Vixen was wider as I too had read the CN review a long time back and always thought it was a bit odd that the maths didn't add up with what was printed on sites. When I was shot to bits I just accepted the people that have them know better, not at all unreasonable on my part.

Alan

You were not the only one who accepted what he read Alan, but I guess we can't personally own and test every eyepiece out there (though some of us are trying !).

[bomberbaz]

41mm Pan sure does sound like the max then. There just happens to be one for sale in Classifieds too if the OP is feeling flush

great idea but its a weight issue with that bad boy I am afraid. I would need a better mount and then its a case of where do I stop. The lens I looked at are in within the mount & scope tolerances, on the edge I know but that would be another 500gm and thats just too much.

I was offered a televue by someone off here already actually. Massive shame because it looks a great , no sorry fantastic piece of kit. I am trying to get hold of a skywatcher aero 40 and also the vixen so I can do some side by side testing. That might tell me enough to make a decision as it will boil down to between those now, as i have discounted the WO Swan 40mm after reading page upon page of review about all 3 aforementioned EP.

Dog with a bone and all that me, hehe

Steve

[alan potts]

SG 00

The only problem with the Panoptic is the same as with the Meade 40mm SWA that I offered him by PM, they are too heavy for an 8 inch, well I told him it would be too heavy, I was thinking of his scope, they are big lumps to move about. I think the 12 inch LX 200 is a bit beefier than the 8 inch by either Company. I have had one dreadful accident this week with a 12mm Nagler which now needs a major refit I don't want to burn out someone motors just to sell an eyepiece on top.

Alan

[michael.h.f.wilkinson]

We are talking very small differences here. If the LVW has the 47mm field stop I saw cited, it will show a 1.146 true FOV in a C9.25. If it is a 46mm (like the WO and the TV 41mm) we get 1.122 deg. Not a big difference.

If weight is an issue, the Aero (Paragon) is a very good option. Mine weighed in at 495 g if I am not mistaken.

[bomberbaz]

I know what you are saying Michael but I ordered the piece based upon several things and one of those was its afov/FL. One of these now is potentially not what it should have been and had I known when i ordered, I doubt I would have bothered.

However i am this far down the line and I am a stubborn sod if nothing else, so I want to find out. Its a mixture of me wanting the EP to be what i thought I ordered and being so blumming minded as to not let it go.

If I cant get hold of the 2 EP's to do a side by side test then I am sacking the order for the vixen off and getting an aero (the EP and a chocolate one), its starting to pee me off now.

Steve

[E621Keith]

Sorry Steve, no luck tonight.

The sky was reasonably clear when I got home, but cloud was moving in by the time I finished polar alignment and balancing my scope. Now I have a total cloud cover even though the forecast says it should be clear.

To pass time, I made some measurement of the 42 LVW. It doesn't have a field stop and the eyepiece barrel internal diameter is >47.5mm. When I put the LVW42 against a blank white computer screen side by side with a 1.25" LVW, and looked through them like a bino. The 42LVW AFOV is considerably wider than all 1.25" LVW I tested (5,13,22). I even swap them left and right to make sure. Whatever its apparent field, the 42 LVW is definitely not 65deg. Unfortunately I don't have my 72deg Nikon with me tonight. I will do a side by side AFOV comparison with them next week.

I will wait another half an hour to see if there is any sign of the clouds clearing. If not, I will call it a night. Due to uncertainty in a SCT's focal length, I can't carry out a reliable drift test with my C8 or C925. It has to be done in one of my refractors, but the 42LVW will produce a true field nearly 6 deg in diameter, so each drift test will take over 20 minutes. It really needs a good continuous spell of clear sky and I don't think I'll get that tonight.

[bomberbaz]

No worries Keith fella, you tried so thank you very much for that.

Although you and Michael are both telling me what I already suspect, that the EP has a much wider afov than the guy at Vixen fobbed me off with. I really don't know, as do none of us what it is but curiosity killed the cat and all that eh.

I have read a string of anecdotal evidence that suggests the AFOV to be much more than 65*. The actual difference between 65 and 72* will be nearly 12% TFOV in my SCT and I can get the same view if it were only 65* from a 40mm Aero for £170 less so dam right it matters.

It would be good if the rep from Vixen who John says is a member on here made an appearance and helped out. I do not believe that the guy from Vixen took my enquiry serious and his last response was a "for gods sake its 65 now go away ok" type reply. Either that or someone doesn't quite understand the importance something like this can actually be and is happy to accept whatever they are told without due diligence themselves, really not sure.

So thanks again, I shall wait and see what FLO come back with and maybe I can make some inroad into this mystery next week. Beginning to feel like the characters outa scoobydoo, pesky peddling kids

Steve

[Stargazer_00]

i dont think a rep is going to give you much really. they are for selling product to outlets rather than providing the technical assurance. I'd expect no better answer than from asking vixen customer services direct. certainly I wouldn't expect a vixen employee to jeopordise their employment by telling you something that customer services wouldn't. id expect the same, somewhat comical, response. japan says 65 degrees.

[bomberbaz]

id expect the same, somewhat comical, response. japan says 65 degrees.

Computer says no

[alan potts]

I would have said that if the likes of Keith who we know has a Vixen 42mm tests it and I know he knows how, if his findings are what ever they are then go on this. I personally believe this will be no more than the Televue Panoptic offers for reasons I stated earlier.

What i can't get my head round it why for ages the sellers of these eyepieces have printed on site that they are 65 degrees FOV and on the eyepiece pictures we clearly see on site the figure 72 and I believe Keith told me his had 72 on it as well. It stikes me there is a case of left hand not know where right hand is never mind it's doing I don't believe this is very good from what is a top Company in the astronomical field. I worked for a very large company and it wouldn't shock me if you never get an answer, our whole customer service dept didn't have the service I have between them and I am talking about 14 people.

Alan

[Stargazer_00]

That 42mm would be their top of the range eyepiece, right? you think they would know what their flagship product is capable of. And Keith's evidence suggests it is 72 degree.