Meade Infinity 102

[Mak the Night]

I'm not sure if they still make Radians, I'm pretty sure the DeLite is its replacement.

[Stu]

23 minutes ago, Mak the Night said:

I'm not sure if they still make Radians, I'm pretty sure the DeLite is its replacement.

Yep, that's basically the case. Radians are certainly not made any more

[Mak the Night]

12 minutes ago, Stu said:

Yep, that's basically the case. Radians are certainly not made any more

It explains why I haven't seen any on Telescope House.

[Ray of LIght]

Thanks guys! I have time to check out the TeleVue line up to see what would be good for my needs. Your advice is highly regarded by me Mak!  

[Mak the Night]

If you really want to splash out, the 24mm Panoptic is still probably the finest in its class. It also Barlows well. Although I didn't tend to use it with one on my 102mm Mak. For Messier Objects and DSO's it is just about perfect. It gave me 54x on the Mak and will really come into its own with the Big Cat for 98x. I could see almost all of M45 with it with its huge 27mm field stop.

[Ray of LIght]

Splash out is right! Agena Astro lists the 24mm Panoptic for 265 US! That would be a treat for sure. I looked at Delos and Naglers and DeLite oh my! We need to talk about FL etc.

[Dave In Vermont]

I agree fully on the TV 24mm Panoptic. I often say that if one only ever buys one TV-eyepiece in their observing life, that's the one I always suggest.

It's that good! MTN hit the nail square-on.

Dave

[Ray of LIght]

Thats great because I own a TV 25mm plossl! I love it. 

[Ray of LIght]

Well Mak, I ordered the 18mm X-Cel LX to fill that one niche so next is the TV 3x and the Baader UHC-S filter. Probably next week. At this point my eyepieces are all LER and nice AFOV. Of course also thinking about the TV Panoptic! Talk in a bit.

[Mak the Night]

Sounds good. I'd give what you've got a good testing first before going mad with a Panoptic lol. That way you can evaluate what suits the scope and intended targets. Sometimes things work out differently to what you expected. The 24mm Panoptic will only be slightly more powerful than your 25mm Plossl. What makes the 24mm Pan special is that its comparatively small and compact size belies the visual experience with it. I only have three EP's with a 27mm field stop, the other two are the TV 32mm Plossl and the Baader 35mm Eudiascopic.

Above is my WO bino with the WO 1.6x Barlow element (included with the unit) threaded into the nosepiece. If you look to the left on the nosepiece and Barlow you can see scratch or score marks where the diagonal set screw has marked them. Brass compression rings were one answer to this marking. The marking doesn't really bother me, but some people find it doesn't look good if they want to sell their equipment on the secondhand market and it could detract from their value. The WO bino also has a tapered undercut on the nosepiece itself. Unfortunately, long periods of use of an eyepiece or nosepiece with a taper in a diagonal/adaptor with a compression ring can cause the compression ring to deform making insertion of eyepieces problematical. The WO bino also has compression rings in each eyeholder/dioptre and yet WO supply eyepieces for the bino with tapered draw tubes!

I've modified these bog-standard Celestron/GSO 13mm Plossls with smooth draw tubes borrowed from another pair of EP's. As I have quite limited use in my right arm and hand the ability to insert and extract eyepieces easily in the dark is preferable to faffing about with things stuck in eyepiece holders and me needing to use much profanity and raising my already astronomically high blood pressure lol!

I've been practising with changing eyepieces in the bino for eventual use with the Big Cat. One of the problems when used with my Mak was the amount of time I could change eyepieces. Changing the Barlow is much more difficult with one hand and I'd often have to sit down on a ground sheet to facilitate this. So it's important to evaluate what you're going to be observing and what magnification range is the most useful. This basically entails on whether to use a Barlow or not and initially setting up with that in mind. Changing individual eyepieces isn't so time consuming. These 13mm Plossls will give me around 181x without a Barlow and 289x with the 1.6x nosepiece. Although I'm repeatedly told I won't be able to use a magnification of more than 200x in the UK I've consistently managed to get around 250x - 270x with a 130mm scope without significant loss of detail. I could see just as much detail recently on Jupiter at 250x as I could at 200x and the conditions were far from perfect. I've always been able to get at least 270x on the Moon with the Bazooka, although I wouldn't expect my 102mm Mak to resolve well at that. But I'm expecting the 9.25" of the Big Cat to resolve well near 300x on many targets. It all depends on conditions of course, hence the magnification range options.

[Ray of LIght]

Fascinating info on the eyepieces and bino viewer. It is going to take some good barlowing to get my 102 to high magnification, as we have discussed. The 9mm  X-Cel with the 3x TV wil give me 200x, maybe a good maximum for my telescope, i think. The 10mm Luminos in my short 2.5 Barlow will give me 150x, good for planets I guess and the Luminos has that nice 82 degree AFOV. Not too bad I'm hoping. I do have the 8mm Starguider to test but I am getting a bad feeling about that eyepiece, just a feeling. That eyepiece in the TV 3x would be 225x, if it works ok. My other eyepieces will be great for lunar and DSO's with no Barlow I believe. How does this sound so far?

[Mak the Night]

I reckon 200x should be fairly easy to achieve with good resolution, although as you know it will entail using a 3mm eyepiece (or the Barlowed equivalent). This will give you a 0.51mm exit pupil. So pushing it a little, particularly with targets like the Moon may be possible. Targets even at 150x will tend to sail out of view relatively quickly so the Luminos 82° FOV will give you significantly more observing time. That's why I originally bought the Luminos, many people have questioned my using a wide angle EP for planetary viewing. But on an undriven mount it makes a lot of sense (and works well). Isn't the Starguider BST (Barsta)? They're quite highly rated on these forums and others. Viewing the Moon at wide angle with around 150x-200x can be quite an experience. Many find the wide angle distracting, but I quite like the 'spacecraft porthole' experience and find it can be quite exhilarating, it's the nearest we can get to being Apollo astronauts lol.  The 8mm EP with a 3x Barlow makes it essentially a 2.6mm EP. This gives you a 0.45mm exit pupil, which is moving away from the preferred 0.5mm minimum. It might work well for lunar viewing but much more than about 10x to 15x above 200x is reaching the resolving limit for a 4" scope. I can get 208x with my 102mm Mak for a 0.49mm exit pupil, which I consider the maximum magnification capable for it. If you can get some eyepiece/Barlow combinations around 170x as well that can be a useful high magnification for a 102mm scope. Low magnifications for DSO's and Messier Objects aren't going to be a problem for your scope. The 18mm X-Cel should give you a 3.1mm exit pupil (un-Barlowed) which is good enough to use the Baader UHC-S effectively. My 102mm Mak needs a 40mm Plossl to achieve the same exit pupil!

[Ray of LIght]

My 9mm X-Cel and 2.5x Barlow will give me close to the 170 mark you mentioned (166x). I think I have many possible combinations, once I get the TV 3x to add to my 2.5 Barlow. Also, i think I will love the Luminos experience, given my alt-az mount as you said. My Starguider has the Agena label on it so I am not sure who makes it. If you recall, that is the eyepiece I had to fix; I'm just hoping I did a good job, lol! 

[Ray of LIght]

Thinking about getting the TeleVue 3x today. Agena has a 100 US price on it right now, I assume that is good. Do you have a picture of it in a diagonal? Trying to figure how tall it will actually be, since my eyepieces are all mostly pretty large. If not no problem. I appreciate all your help Mak!

[Mak the Night]

4 hours ago, Ray of LIght said:

My 9mm X-Cel and 2.5x Barlow will give me close to the 170 mark you mentioned (166x). I think I have many possible combinations, once I get the TV 3x to add to my 2.5 Barlow. Also, i think I will love the Luminos experience, given my alt-az mount as you said. My Starguider has the Agena label on it so I am not sure who makes it. If you recall, that is the eyepiece I had to fix; I'm just hoping I did a good job, lol! 

I'm pretty sure the Starguider is Barsta aka BST aka Paradigm.

Barsta 1.25" (Paradigm) ED Eyepieces

[Mak the Night]

1 hour ago, Ray of LIght said:

Thinking about getting the TeleVue 3x today. Agena has a 100 US price on it right now, I assume that is good. Do you have a picture of it in a diagonal? Trying to figure how tall it will actually be, since my eyepieces are all mostly pretty large. If not no problem. I appreciate all your help Mak!

It's not as ungainly as it looks. I regularly used my T5 Nagler on top of the Powermate.

[Ray of LIght]

The Starguiders do look the same. Might be ok. Barsta is good, right? I might be lucky with this one. As far as the TV Barlow I'm sure it will be a great addition to my kit, and then some. Thanks for the picture Mak!

[Mak the Night]

6 minutes ago, Ray of LIght said:

The Starguiders do look the same. Might be ok. Barsta is good, right? I might be lucky with this one. As far as the TV Barlow I'm sure it will be a great addition to my kit, and then some. Thanks for the picture Mak!

You're welcome Ray, I hope the picture assuages any fears you have about the size of the TV 3x. Yeah, Barsta make some quality gear. This Omegon shorty apochromatic 2x Barlow is actually Barsta. I rarely used shorty Barlows in the 102mm Mak diagonal even though I bought this with the 90mm Mak in mind. It's seen some use on the Bazooka. They can cost anywhere between £65 and £90 here depending which brand name is on it. TeleVue don't do 'shorty' Barlows as they don't believe the light path is good enough. However, they can be convenient. Personally, after using this Barlow for a few times, I'm convinced that optically it's not far off TV quality. It bloody well should be for the price I paid for it lol! The build quality might not quite be TeleVue standard, but even so, it is good.

If the Agena is the same quality, it should be very good. The Starguider/Paradigm/BST have a very good reputation.

[Ray of LIght]

14 hours ago, Mak the Night said:

You're welcome Ray, I hope the picture assuages any fears you have about the size of the TV 3x. Yeah, Barsta make some quality gear. This Omegon shorty apochromatic 2x Barlow is actually Barsta. I rarely used shorty Barlows in the 102mm Mak diagonal even though I bought this with the 90mm Mak in mind. It's seen some use on the Bazooka. They can cost anywhere between £65 and £90 here depending which brand name is on it. TeleVue don't do 'shorty' Barlows as they don't believe the light path is good enough. However, they can be convenient. Personally, after using this Barlow for a few times, I'm convinced that optically it's not far off TV quality. It bloody well should be for the price I paid for it lol! The build quality might not quite be TeleVue standard, but even so, it is good.

If the Agena is the same quality, it should be very good. The Starguider/Paradigm/BST have a very good reputation.

Actually, my HPS 2.5 looks very well made also, was not overly expensive, but not sure who makes it. I sent a couple of pictures of it. As far as the Starguider, in the 2.5 it will give me 187.5x, not bad for my scope. I will be ordering the TV 3x today, Agena usually delivers fairly quickly. My 18mm X-Cel arrives tomorrow, should be nice! Talk in a bit.

[Mak the Night]

Your High Point Barlow is almost certainly a Guan Sheng Optical (GSO) apochromatic 2.5x Barlow. It is marketed here under a variety of names including GSO.

Earlier models featured safety undercuts, which have become so controversial in recent times that GSO have actually discontinued undercuts on most of their products recently.

I bought mine from TS Optics, in fact it was someone from TS Optics who informed me about GSO ceasing putting undercuts on draw tubes. This is why the new Orion Sirius Plossls have no undercuts, as they're all basically re-badged GSO. Personally, I think TeleVue have virtually solved the undercut problem with their flared lower lip design. This is another reason that if I spend a lot of money on an eyepiece, it's almost certainly a TeleVue. I know that some people have approached Al Nagler and asked him if he'd consider removing the undercuts from TV eyepieces. I don't think he was particularly impressed by these requests. IMO TV have more or less nailed the problem. I like to test eyepieces with undercuts in my bino, if I can extract them easily from that, they can be extracted from anything! My 15mm TV Plossl pair extract easily from the bino. So the TV lower lip flare does work. You can see the TV lower lip flare below on this comparison of three 15mm EP's: a TV Plossl, a smooth 15mm Kellner and a 15mm Omni with a standard GSO aluminium draw tube and undercut. The lower lip flare on the TV eases extraction as it doesn't get so hung up as the EP is withdrawn from the diagonal/adaptor's compression ring.

The 2.5x GSO Barlow is pretty decent quality. I can't fault the optical glass. I've been using mine a lot with the X-Cel on the Bazooka to get 250x. I have a TV 2.5x Powermate but it is long and is often pointing downwards on the Bazooka, so a shorter Barlow/amplifier is much more convenient. I bought mine also for use with the 90mm Mak, but it's seen far more action with the Bazooka. It's difficult to say, but I can't tell any real difference between it and the TeleVue 3x for quality of viewing. A lot of the myths about Barlows degrading the image are like those about Amici prism diagonals. They belong to an era when poor quality Barlows and Amici prisms were more common. Times have changed lol.

[Ray of LIght]

Wow, you nailed this one! My 2.5 looks exactly like the GSO and has no safety undercut as you pointed out. Pretty sure it will be a good Barlow. Most of my eyepieces do have those undercuts to varying degrees but they seem to extract from my WO diagonal with no problem. Be back in a bit. 

[Mak the Night]

The X-Cel, Luminos, Vixen NPL's and my 15mm Antares UPL tend to extract relatively well. Many of the lighter GSO draw tubes can be tricky though, especially as I have to insert and extract eyepieces with my left (non-dominant) hand only. One of the problems for me is when an eyepiece snags half way through the extraction process, sometimes I can use my right arm/hand to hold it in place before further manipulation with my left. The bino dioptres are particularly tricky though and I'll only use smooth draw tubes in them. Don Pensack told me about how tapered draw tubes can damage compression rings, and I believe he replaces all of the set screws on his own gear with nylon screws, and he actually removes compression rings as well. My StarSense Autoalign has set screws with nylon tips.

[Ray of LIght]

Well my 18mm arrived, maybe try some stuff tonight. Hoping to get the 3x TV by Monday, but I dont know. Been doing some review research and the TV 3x Barlow is very highly rated. Very highly. As you have been saying. It sounds like it is worth a little "stove piping", lol. Talk in a bit.

[Mak the Night]

10 minutes ago, Ray of LIght said:

Well my 18mm arrived, maybe try some stuff tonight. Hoping to get the 3x TV by Monday, but I dont know. Been doing some review research and the TV 3x Barlow is very highly rated. Very highly. As you have been saying. It sounds like it is worth a little "stove piping", lol. Talk in a bit.

I hope you get to test this new gear Ray. It's been warm here, with a thunderstorm or two, and I'm not optimistic about tonight. At 22:00 BST the GRS will be visible. Plus the Moon should be visible for a while.

Sometimes I can see Metis, Amalthea and other smaller moons.

Could be some good Terminator shadows around the Sea of Tranquillity.

Although I very much doubt I'll have the transparency, it would be interesting to look for some MO's like the Trifid Nebula. Maybe time to dig the UHC-S out and a 25mm EP!

[Ray of LIght]

You mentioned the UHC-S  and 25mm eyepiece. Reminds me I need to order that filter. Now I am not sure which one, Baader or ES. I would like to order the ES but I am wary since once I know what I am doing I may want to spend a lot of time on DSO's and want the best filter I can afford. Then again, like you pointed out, the ES are individually tested. Not a bad practice. Unsure.