Explore Scientific 6.7mm 82*

[MortonH]

Originally Posted by MortonH

I've read a few posts on Cloudy Nights saying that ES sent felt rings out to owners who complained about the glare issue. So I've emailed them today asking for some to be sent out. I'll post an update when they respond.

Morton

Took a few days but Explore Scientific have replied and are sending me out the "fix". It's some kind of adhesive ring that attaches to the bottom of the eyepiece.

The person that first replied to my email hadn't actually heard of the issue or the fix, so I had to be a little persistent!

Since the rings are adhesive they are probably not permanent. I have asked them to send me some spares as well.

There's no charge for this so I'd encourage other owners to test their eyepieces on the Moon and contact ES support if they have the same glare issue.

[David Niven (David Niven)]

I have seen the 8.8 going for $135 on ebay.
But if you look at the photo, it is the old N2 not the current Argon purged ones.

[209herschel (Herschel)]

Absolutely right. I didn't even know there was a difference! I'll be buying the 6.7 from vti (or anywhere I can find it cheaper) and this will be my lunar/planetary eyepiece.

I also have the 30mm GSO superview. For now, until I can afford a higher quality eyepiece for DSOs, does this seem sound? I also have 9mm, 15mm and 25mm plossls.

I haven't yet seen the Lagoon Nebula, galaxies, and many other things I'm keen to still find but I'm new to this and I enjoy looking at lunar craters, Saturn, etc. Thanks.

Originally Posted by David Niven

I have seen the 8.8 going for $135 on ebay.
But if you look at the photo, it is the old N2 not the current Argon purged ones.

[MortonH]

Originally Posted by David Niven

I have seen the 8.8 going for $135 on ebay.
But if you look at the photo, it is the old N2 not the current Argon purged ones.

As far as I know most of the current 82D eyepieces are still purged with Nitrogen. They are moving to Argon though.

As long as the eyepiece is unused I wouldn't care what gas is inside!

[MortonH]

Originally Posted by 209herschel

Absolutely right. I didn't even know there was a difference! I'll be buying the 6.7 from vti (or anywhere I can find it cheaper) and this will be my lunar/planetary eyepiece.

I also have the 30mm GSO superview. For now, until I can afford a higher quality eyepiece for DSOs, does this seem sound? I also have 9mm, 15mm and 25mm plossls.

I haven't yet seen the Lagoon Nebula, galaxies, and many other things I'm keen to still find but I'm new to this and I enjoy looking at lunar craters, Saturn, etc. Thanks.

That's a good spread of eyepieces you have. The 30mm Superview might give too little magnification unless you're under a dark sky. In light polluted areas the background sky will likely be too bright, making it harder to pick out faint objects. It will be useful to find objects in its wider FOV, but once you're centred on the object you'll probably want a higher power to increase contrast. The 15mm and 9mm Plossls will be very good for many, many deep sky objects.

[209herschel (Herschel)]

Thanks again. I also have a TMB 9mm. So I'll buy the 6.7mm ES for the added magnification and FOV, and use the other eyepieces. Then down the road I'll aim to get something like a TV Panoptic for DSOs.

Originally Posted by MortonH

That's a good spread of eyepieces you have. The 30mm Superview might give too little magnification unless you're under a dark sky. In light polluted areas the background sky will likely be too bright, making it harder to pick out faint objects. It will be useful to find objects in its wider FOV, but once you're centred on the object you'll probably want a higher power to increase contrast. The 15mm and 9mm Plossls will be very good for many, many deep sky objects.

[MortonH]

Sounds like a good plan.

By the way, the reason so many eyepieces are expensive is the wide field of view. But in many cases a good Plossl lets more light through because it has fewer glass elements. So for deep sky stuff at lower magnifications a Plossl may be all you need .

[209herschel (Herschel)]

Thanks very much. I'll keep that in mind.

I just wanted to ask what the Lagoon Nebula looks like in a scope? I've got a 10" GSO. Using a 30mm eyepiece, I saw the Lagoon Nebula last night but not the red haze that it shows on Stellarium but a faint grey. I also saw the Triffid Nebula close by, smaller. 90% of the sky was thick cloud last night and the neighbours lights were very bright but I thought I'd see that reddish smear. Thanks again.

Originally Posted by MortonH

Sounds like a good plan.

By the way, the reason so many eyepieces are expensive is the wide field of view. But in many cases a good Plossl lets more light through because it has fewer glass elements. So for deep sky stuff at lower magnifications a Plossl may be all you need .

[209herschel (Herschel)]

Thanks everyone for your advice. I'm down to two choices: ES 6.7 and Pentax xf 8.5, both of which are around $200 delivered from VTI. If you have both or have used them, I'd appreciate your thoughts on what you'd recommend for use with my 10" GSO, used 95% of the time in my backyard, Inner City Sydney. My thoughts are the ES has an 82 degree field but I'm concerned the 6.7 might be too much on some nights so it won't get as much use. I already have a 9mm plossl so if the magnification of the 6.7 over the 8.5 is significant without too much loss of clarity, I'd probably go with the ES. Thanks again.

[MortonH]

I have both the ES 6.7mm and the XF 8.5mm.

The ES 6.7mm will give you around 186x magnification, which sounds about perfect for planetary unless you have poor seeing. It also has a flatter field than the XF 8.5mm (as well as being wider) so will allow quite a bit more time between nudges.

If you're worried the magnification is too high then I'd seriously consider the ES 8.8mm you saw for around $135.

[Camelopardalis (Dunk)]

Originally Posted by 209herschel

...but I thought I'd see that reddish smear

It's unlikely that you'll see colour in DSOs, but not impossible.

Our eyes see things by the use of rods and cones. In simplistic terms, the rods take care of luminance and the cones take care of colour. In low light, the cones are inactive and only the rods are active, which is why we see essentially only in monochrome in the dark.

Some objects - brighter planets for example - can activate the cones again, which is why many of us see coloured feature on them.

Read up on photopic vs scotopic vision for more details.

[Steffen]

Just regarding the flatness of field, I can't detect any lack of it with the XF 8.5 in my (totally flat field) Mak. It obviously has a much narrower apparent field of view than the ES 6.7, but from memory the field that it does show is sharp all the way across. I shall double check to be sure as soon as the clouds part.

Cheers
Steffen.

[209herschel (Herschel)]

Thanks very much. My 9mm GSO plossl is the highest mag eyepiece I've got, giving 133x on my 10" dob. My concern with the Pentax is that it would only give a fraction more. I could barlow it but then I'm down to 4.25mm and I think I'd lose all clarity in my backyard almost all of the time. The ES 6.7 seemed a good amount of magnification but still allowing a lot of use. Does that sound right?

Originally Posted by Steffen

Just regarding the flatness of field, I can't detect any lack of it with the XF 8.5 in my (totally flat field) Mak. It obviously has a much narrower apparent field of view than the ES 6.7, but from memory the field that it does show is sharp all the way across. I shall double check to be sure as soon as the clouds part.

Cheers
Steffen.

[MortonH]

Originally Posted by 209herschel

Thanks very much. My 9mm GSO plossl is the highest mag eyepiece I've got, giving 133x on my 10" dob. My concern with the Pentax is that it would only give a fraction more. I could barlow it but then I'm down to 4.25mm and I think I'd lose all clarity in my backyard almost all of the time. The ES 6.7 seemed a good amount of magnification but still allowing a lot of use. Does that sound right?

Sounds right to me!