'Mavis Laven'

[Nightspore]

5mm 'Mavis Laven' TMB clone:

 

 

Just under 14 quid brand new!

[Marmot]

And is it 14 quid well spent? How does it perform?

[Nightspore]

39 minutes ago, Marmot said:

And is it 14 quid well spent? How does it perform?

 

I don't know yet, but I bet it's as good as the TS Optics/BST 5mm I bought several years ago.

 

 

I've been testing these 'Mavis Laven' TMB's for a while now. One or two have been under other names. I'm betting they're all from the same factory. 

 

 

I usually have to tighten the lens group collar as these are renown 'rattlers'.

 

 

Most have been about £30 and I got them all from Amazon.

 

 

I'm not sure how they compare with Thomas Back's original Burgess Optical design. Although they not only very probably originate from the same factory, I've read that they also perform identically.

 

 

I find that they're very sharp and defined, with good colour separation and excellent contrast, particularly on-axis, with little or no lateral colour. Almost like 58 degree orthoscopics. They were originally designed for planetary so there can be a little edge astigmatism. Apparently the 25mm was an accident of misunderstanding between TS Optics and the Chinese manufacturer. It was supposed to be a 2.5mm but someone misread the plans. Whether this story is apocryphal or not I don't know. But the 25mm HR is great for rich field in a lightweight refractor. 

Edited June 4, 2021 by Nightspore

[Marmot]

Strangely enough I am looking for a 25mm to replace the “Skywatcher super 25” that I am currently using. I have managed to acquire various eyepieces for all the other focal lengths that are useful to me, but I was holding off on something of about 25mm as I was getting by with the supplied Skywatcher EP. It may be worth me keeping. An eye out for one of these. 

Do you know what the FOV is?

[Nightspore]

7 hours ago, Marmot said:

Strangely enough I am looking for a 25mm to replace the “Skywatcher super 25” that I am currently using. I have managed to acquire various eyepieces for all the other focal lengths that are useful to me, but I was holding off on something of about 25mm as I was getting by with the supplied Skywatcher EP. It may be worth me keeping. An eye out for one of these. 

Do you know what the FOV is?

 

58 degrees. They work pretty well in fast scopes, particularly refractors IME. 

 

 

I was quite disappointed when I tried the 25mm BST StarGuider (above left). It really suffered badly from astigmatism in an f/5.8 ED doublet. Serious seagulls! The TS Optics was far superior. Neither have Smyth lenses.

[Marmot]

3 hours ago, Nightspore said:

 

58 degrees. They work pretty well in fast scopes, particularly refractors IME. 

 

 

I was quite disappointed when I tried the 25mm BST StarGuider (above left). It really suffered badly from astigmatism in an f/5.8 ED doublet. Serious seagulls! The TS Optics was far superior. Neither have Smyth lenses.

That’s useful to know and it confirms other things I have read about the 25mm Starguider. I have a small number of StarGuiders at present, all of which I am pleased with, but I had not rushed to get the 25mm for just the reasons you mention. I do like the 60deg field of view as I find it more comfortable than the narrower field EPs, so the pieces you have mentioned sound like they may well suit me.

on a side note, concerning the Starguiders: The ones I own (8, 12, 15, 18) are all nicely parfocal (think that’s the word) apart from the 8mm which requires a slight refocus when using immediately after one of the others.

[Nightspore]

6 hours ago, Marmot said:

That’s useful to know and it confirms other things I have read about the 25mm Starguider. I have a small number of StarGuiders at present, all of which I am pleased with, but I had not rushed to get the 25mm for just the reasons you mention. I do like the 60deg field of view as I find it more comfortable than the narrower field EPs, so the pieces you have mentioned sound like they may well suit me.

on a side note, concerning the Starguiders: The ones I own (8, 12, 15, 18) are all nicely parfocal (think that’s the word) apart from the 8mm which requires a slight refocus when using immediately after one of the others.

 

The 3.2mm StarGuider I have is predominantly used for lunar/planetary. It's been my go to Mars eyepiece for years for some reason lol. I even used it with last year's Mars opposition in my f/6, 150mm Newtonian. It has a Smyth lens (like a Barlow) in the barrel which probably ameliorates any edge astigmatism. The 25mm doesn't have a Smyth. My 25mm StarGuider works well in slow scopes (f/12 and slower). The 25mm TS Planetary will show some edge astigmatism around f/5~6, but a large amount of the field is fine. I doubt it has ED glass like the StarGuiders though.

[Marmot]

On 6/4/2021 at 10:49 AM, Nightspore said:

5mm 'Mavis Laven' TMB clone:

 

 

Just under 14 quid brand new!

 

Snap!!

Arrived today. Thanks for the info on eyepiece and the link to get it at the same price.

It arrived complete with the rattle, but 5 mins following your instructions, retaining collar tightened and rattle gone.

I currently enjoy wide field views and generally trying to learn my way around the sky. For that reason I was reluctant to pay too much on an EP of a focal length that I would only get occasional use from. This fits the bill perfectly. 

I have just tried it on a daytime target and no complaints. It certainly seems very, very, good value.

 

Thanks again.

[Nightspore]

2 hours ago, Marmot said:

 

Snap!!

Arrived today. Thanks for the info on eyepiece and the link to get it at the same price.

It arrived complete with the rattle, but 5 mins following your instructions, retaining collar tightened and rattle gone.

I currently enjoy wide field views and generally trying to learn my way around the sky. For that reason I was reluctant to pay too much on an EP of a focal length that I would only get occasional use from. This fits the bill perfectly. 

I have just tried it on a daytime target and no complaints. It certainly seems very, very, good value.

 

Thanks again.

 

Looks great. I was using the 3.2mm version with my 72ED last night. It's great for splitting doubles.

 

 

Another trick is that you can thread the barrel/Smyth lens off in one unit (the short bit with the flare). This reveals the actual field lens. Any dust that's settled on the internal field lens can been blown off with an air blower.

 

 

Resist the temptation to clean this lens with a cloth though as it can sometimes leave more debris than you remove. 

 

 

Here's a couple of targets to test it on:

 

 

Find the 'W' of Cassiopeia and the two left end stars roughly point to Iota Cassiopeiae. This is a beautiful triple star. 

 

 

Find Arcturus and just above it is Izar. 

 

 

Have fun.

Edited June 9, 2021 by Nightspore

[Marmot]

Thanks again.

you must have read my mind: splitting a double or two is on my list of things to do in the near future and I have started researching suitable targets. I have been trying not to run before I can walk, so I have been putting time in just trying to get to know my way around the sky and my kit. (Experimenting with differing EPs etc).  I have done some ‘screen snaps’ of the pics you provided above and I will add them to my growing reference file🙂

[Nightspore]

4 minutes ago, Marmot said:

Thanks again.

you must have read my mind: splitting a double or two is on my list of things to do in the near future and I have started researching suitable targets. I have been trying not to run before I can walk, so I have been putting time in just trying to get to know my way around the sky and my kit. (Experimenting with differing EPs etc).  I have done some ‘screen snaps’ of the pics you provided above and I will add them to my growing reference file🙂

 

These are two of my current favourites, they're not particularly difficult to find. Should be no problem at 120x with your 120mm achromat. The night sky is full of doubles. Probably the most famous is Abireo in Cygnus. 

 

Not to leave out the first double ever recorded: Mizar

 

The 200 double stars in the constellations :

[Marmot]

I thought I would update this thread with my latest purchase. It may be of interest to any observers out there, particularly those on a given budget.

 

I read Nightspore comments on these eyepieces with great interest and subsequently purchased the 5mm Mavis Laven eyepiece shown above from the link supplied.

Out of interest I rechecked Amazon and found the price has now slightly increased! I looked on Amazon at the differing focal lengths and as stated in the thread found what looked like the same eyepiece under different names. (Nightspore has already mentioned they are available under differing names) One in particular jumped out at me as I was looking at the 6mm versions.

The 6mm Planetary eyepiece by “Topiky”.

there was a very limited stock and they were at a very low price with an extra 5% reduction due to an Amazon voucher. So I purchased it thinking it was cheap enough to risk the loss and that it may be fun to compare it to the Mavis Laven 5mm that I was pleased with.

it arrived in an identical box, with the same identification sticker on the lid. The only external difference was a small “Topiky” sticker instead of the “Mavis Laven” sticker. On opening it I found it inside the same plastic bag.

the eyepiece is identical in build, and Required the retaining collar to be tightened in the same way to stop a very slight rattle.

i have done a side by side daytime comparison and found it to perform the same although obviously at a slightly differing mag comparing a 5mm to a 6mm.

 

So as I said at the start, this is purely for the info of any observers looking for what seems a reasonable eyepiece that is budget friendly.

 

Oh yes, I nearly forgot to mention the price. A grand total of £6.85p delivered!

 

[Nightspore]

1 hour ago, Marmot said:

I thought I would update this thread with my latest purchase. It may be of interest to any observers out there, particularly those on a given budget.

 

I read Nightspore comments on these eyepieces with great interest and subsequently purchased the 5mm Mavis Laven eyepiece shown above from the link supplied.

Out of interest I rechecked Amazon and found the price has now slightly increased! I looked on Amazon at the differing focal lengths and as stated in the thread found what looked like the same eyepiece under different names. (Nightspore has already mentioned they are available under differing names) One in particular jumped out at me as I was looking at the 6mm versions.

The 6mm Planetary eyepiece by “Topiky”.

there was a very limited stock and they were at a very low price with an extra 5% reduction due to an Amazon voucher. So I purchased it thinking it was cheap enough to risk the loss and that it may be fun to compare it to the Mavis Laven 5mm that I was pleased with.

it arrived in an identical box, with the same identification sticker on the lid. The only external difference was a small “Topiky” sticker instead of the “Mavis Laven” sticker. On opening it I found it inside the same plastic bag.

the eyepiece is identical in build, and Required the retaining collar to be tightened in the same way to stop a very slight rattle.

i have done a side by side daytime comparison and found it to perform the same although obviously at a slightly differing mag comparing a 5mm to a 6mm.

 

So as I said at the start, this is purely for the info of any observers looking for what seems a reasonable eyepiece that is budget friendly.

 

Oh yes, I nearly forgot to mention the price. A grand total of £6.85p delivered!

 

 

Yeah, these all come out of the same factory. Just under 7 quid is brilliant though.