48 replies to this topic

[Adri_Bha]

My telescope: Sky-Watcher Classic 250P Dobsonian (10 inch aperture, 1200mm focal length, F/Ratio: 4.7)

 

WHAT I'M LOOKING FOR:
Hello Cloudy Nights. I am currently looking for good 5mm and 7mm eyepieces. I narrowed down to the following since they're within my budget:

WHAT I'VE CONSIDERED SO FAR:

• Tele Vue 5mm DeLite VS Pentax 5mm XW
• Tele Vue 7mm DeLite VS Pentax 7mm XW

My scope is quite fast, so it's not so forgiving. The Pentax XW is slightly cheaper than the Tele Vue DeLite. They both have the same eye relief of 20mm, but the Pentax has a wider Apparent Field of View (70 degrees) than the DeLite (62 degrees), which is really nice to have. So why is it cheaper exactly, and what would I be sacrificing if I got the Pentax XW over the Tele Vue DeLite? Are the DeLites really that much better, that even with a smaller AFOV they're more expensive? For some reason, I'm having a hard time being convinced that they are.

Note: I made a similar post before about high power eyepieces, and decided to get the Tele Vue 6mm Delos. I wanted a higher and lower magnification in my collection. Thank you.

Edited by Adri_Bha, 03 April 2025 - 11:54 PM.

[JoeBlow]

I haven't tried the Delites, but I have the 7mm XW which is a very highly regarded eyepiece in the XW range. The Delite could be slightly better in some regards, but the XW no doubt has the wider FOV advantage. Also just because one eyepiece is more expensive than another, doesn't necessarily mean it's better. Have you also considered the Morpheus eyepieces? They are also very highly regarded in those focal ranges and have even wider FOV. Many people prefer them over the XWs.

[CrazyPanda]

I own the 7 XW and 7 DeLite.

 

The 7 DeLite is very slightly sharper than the 7 XW. It's close, but excellent seeing reveals the difference. The difference is most easily seen on Saturn. All the edges of the rings are tighter in the 7 DeLite than the XW. The definition between the shadow of the ring, the outer ring, and the inner ring across Saturn is more stark in the DeLite than the XW. On Jupiter, they perform similarly, with a *slight* edge in color rendition in favor of the 7 DeLite.

 

I keep a pair of 7 DeLites in my case for binoviewing, but I keep the 7 XW for monoviewing alongside a 6 Delos and a 5 XW.

 

Truth be told I cannot recommend the 7XW over the 7 DeLite or vice versa. I like them both. The 7 XW is very comfortable and the wider field is nice in a non-tracking scope.

 

I used to pop the 7 DeLite into the focuser on those nights when the seeing justified it, but then I realized that if the seeing is good enough to split hairs between the 7 XW and 7 DeLite, it's good enough for more magnification, which is better than EITHER of those 7mm eyepieces.

 

I have a 7 X-Cel LX (which is 6.5mm) for such occasions, and if the seeing is really, really, really good, I'll just put the 6 Delos in.

 

Since you already have a 6 Delos, I would get the 7 and 5 XWs. The AFOV will feel consistent, and for those nights where the view is razor sharp, you're going to want to pop the 6 Delos in the focuser anyway.

 

I can't speak to the 5 DeLite vs 5 XW since I don't own the DeLite, but at the higher magnification of a 5mm eyepiece, you're going to want that extra drift time from the wider field of view.

 

Also, I highly recommend a Paracorr if you want the best performance out of these premium eyepieces.

Edited by CrazyPanda, 04 April 2025 - 12:11 AM.

[Adri_Bha]

Thank you all for the replies. These are fantastic suggestions!

[SeattleScott]

Using a F4 visually, I am fairly picky about edge correction. I went with the 5 and 7 Nikon SW. As best I can tell, most people tend to slightly prefer the 7SW to the 7XW, and the 5XW to the 5SW, so it is a bit of a toss-up. But I liked the form factor of the Nikons better. I think of the Nikons as more or less having Delos/XW AFOV with Delite form factor. Granted, technically the Delite are smaller/lighter than the Nikons, but the short focal length Nikons are certainly smaller/lighter than Delos/XW. 

 

In your case though, because you already got the 6 Delos, I would probably get the Delite, at least at 5mm. At high power, parfocal eyepieces are nice. Tonight I was looking at the Moon and Jupiter with my 6" Mak. It was nice dialing in the focus with my 10SW, and then swapping to the 7SW and it was already in perfect focus. At around 300x. The Delites will be parfocal with your Delos. The XWs won't. Neither will the Nikons. Especially with a manual scope, you don't want to be wasting time adjusting focus as the target is drifting out of view. Granted, with 70/72 AFOV, at least you have more time before stuff drifts out of view, so there's that. But personally, I would go for parfocal over the extra AFOV. The Delites will also have a similar tone as the Delos, as opposed to a cooler Pentax or Nikon. So you can have consistent AFOV, or you can have consistency in parfocality and tone. And the small form factor of the Delites certainly won't hurt.

[Adri_Bha]

That's very interesting. I didn't realize the DeLites are parfocal with the Delos. That's a very good point you bring up. Thanks!

[eblanken]

Hello Adri_Bha,

 

{EDIT: Welcome to the eyepiece forum of Cloudy Nights [CN] !!!}

 

My telescope: Sky-Watcher Classic 250P Dobsonian (10 inch aperture, 1200mm focal length, F/Ratio: 4.7)

 

WHAT I'M LOOKING FOR:
Hello Cloudy Nights. I am currently looking for good 5mm and 7mm eyepieces. I narrowed down to the following since they're within my budget:

WHAT I'VE CONSIDERED SO FAR:

• Tele Vue 5mm DeLite VS Pentax 5mm XW
• Tele Vue 7mm DeLite VS Pentax 7mm XW

My scope is quite fast, so it's not so forgiving. The Pentax XW is slightly cheaper than the Tele Vue DeLite. They both have the same eye relief of 20mm, but the Pentax has a wider Apparent Field of View (70 degrees) than the DeLite (62 degrees), which is really nice to have. So why is it cheaper exactly, and what would I be sacrificing if I got the Pentax XW over the Tele Vue DeLite? Are the DeLites really that much better, that even with a smaller AFOV they're more expensive? For some reason, I'm having a hard time being convinced that they are.

Note: I made a similar post before about high power eyepieces, and decided to get the Tele Vue 6mm Delos. I wanted a higher and lower magnification in my collection. Thank you.

 

Thank you for your post. I especially appreciate your use of BOLD & Underline.

 

I own a full set of Pentax XW (68 Degree) eyepieces: 40mm, 30mm, 20mm, 14mm, 10mm, 7mm, 5mm & 3.5mm

 

I also own full set of TeleVue Delites (62 Degree): 18.2mm, 15mm, 13mm, 11mm, 9mm, 7mm, 5mm, 4mm & 3mm and in addition

I furthermore own TeleVue Radians (57 Degree) in the even mm sizes to interleave with the DeLites, so 12mm, 10mm, 8mm, 6mm, etc.

 

All these are pretty good eyepieces. I would say that "sandwiching" a 6mm Delos in between a 7mm & 5mm DeLite set is a good approach.

 

I like my Pentax XW set. They are larger Apparent Field of View (AFoV) and physical size. They are very easy and comfortable.

 

My advice is to carefully consider if you value the Parfocal nature of the TeleVue against the added drift time of the Pentax ?

 

Furthermore, is the difference of "sandwiching" the Delos 6mm between the two Pentax XW 7mm & 5mm going to work for you ?

 

Is the possibly superior Edge control of the DeLite valuable to you (especially if you are giving up 6 Deg. AFoV) ?

 

Best,

 

Ed

 

P.S. Also you may want to consider the APM Super-ZOOM (15.4mm-7.7mm, 67 Degrees AFoV) which I also recommend . . .

Edited by eblanken, 04 April 2025 - 01:08 AM.

[Adri_Bha]

Hi eblanken, thank you. I try highlighting the main point of interest with bold/underline to make it easier to read.
And that's a really impressive collection of eyepieces. I'm jealous, Haha!

[nkoiza]

This is pretty straightforward. You'll likely struggle to notice much difference (if at all) optically, but you will notice an obvious difference in the size of the apparent field of view, especially as you are already used to TV Delos with a field of view in a similar category to the XW.

 

I have never been tempted to sell my 7mm and 5mm Pentax XWs, even after 20 years of use and with new lines becoming available. They are really that good.

Also, I tend to reach out for my 5mm XW over my 5mm Pentax XO, although the field of view of the XO is obviously much smaller.

[Highburymark]

The optical quality (barring AFOV) of these premium, complex eyepieces is so close that you’ll read a thousand opinions and be little clearer. I’d choose Delite if you want a smaller, lighter eyepiece, XW if you want comfort and medium-width, and Morpheus if you want to save a bit of cash and a wider field. But at these focal lengths they will all perform very well. To get any better performance on axis, you’d need specialist planetary eyepieces.

[Neanderthal]

....My scope is quite fast, so it's not so forgiving. The Pentax XW is slightly cheaper than the Tele Vue DeLite. They both have the same eye relief of 20mm, but the Pentax has a wider Apparent Field of View (70 degrees) than the DeLite (62 degrees), which is really nice to have....

Keep in mind these AFoV's will decrease with the use of most coma correctors. Have you considered the Baader Morpheus line (if you or a co-observer wears eyeglasses)? Or the Astro-Tech UWA's (non-eyeglass wearer)?

[CrazyPanda]

Keep in mind these AFoV's will decrease with the use of most coma correctors. Have you considered the Baader Morpheus line (if you or a co-observer wears eyeglasses)? Or the Astro-Tech UWA's (non-eyeglass wearer)?

A coma corrector will not affect the AFOV. It will affect the TFOV if the coma corrector has a barlow effect, but it will not change the AFOV. That's an inherent attribute of the eyepiece.

[Neanderthal]

A coma corrector will not affect the AFOV. It will affect the TFOV if the coma corrector has a barlow effect, but it will not change the AFOV. That's an inherent attribute of the eyepiece.

Always get those mixed up. Regardless, most coma correcting tools will reduce the FOV that is seen. Just making the OP aware so there's no surprise.

[Bill Barlow]

 

I own a full set of Pentax XW (68 Degree) eyepieces: 40mm, 30mm, 20mm, 14mm, 10mm, 7mm, 5mm & 3.5mm

 

I believe the Pentax XW’s have a 70 degree FOV.  I also own a complete set and enjoy them very much.  Thinking about getting the 3mm DeLite since the XW’s stop at 3.5mm.

 

Bill

[SeattleScott]

I believe the Pentax XW’s have a 70 degree FOV. I also own a complete set and enjoy them very much. Thinking about getting the 3mm DeLite since the XW’s stop at 3.5mm.

Bill

They are marketed as 70 AFOV. I think certain focal lengths have been measured at 68-69 AFOV so that might be what Ed is referring to. But yeah, I think of them as 70 AFOV. I believe the 7XW has the same field stop size as the 7SW, which is supposed to be 72 AFOV.

[csrlice12]

My Pentelos collection...learn the lost art of the twirly knobs...

 

[Procyon]

Pentax XW's also work great on Globular Clusters. I tried a 10mm Tv Delos vs a 10mm Pentax XW on various globulars one night and one seemed to outdo the other on various parts of the cluster. The Pentax XW seems like a steal at the price they are going for today. I paid more for one back in 2009. I still keep and buy Delos/Pentax XW's. Tried a Delite, it wasn't for me.

Edited by Procyon, 04 April 2025 - 12:13 PM.

[SeattleScott]

Another consideration. The Delos focuses about the same amount further out as the width of a parfocal ring. So you could get a 7XW or 7SW and still have parfocal eyepieces by purchasing a single 1.25” parfocal ring. This would give you consistent AFOV with the Delos. Tone would still be different, although not necessarily a bad thing.

[csrlice12]

Optically it's a tossup....ergonomically the XWs win.

[areyoukiddingme]

I only have the 18.2 Delite to go on, but I while I really like the 7XW, it does have a bit of lateral color that is evident on the planets. But I really like it in my 12.5" reflector. 

 

I have not warmed to the 5mm XW quite as much. The field feels smaller than 70 degrees, and I also see the lateral color on plants.

 

These are quibbles, but if you are looking for the sharpest image on plants, this might be worth consideration. 

[TayM57]

I only have the 18.2 Delite to go on, but I while I really like the 7XW, it does have a bit of lateral color that is evident on the planets. But I really like it in my 12.5" reflector. 

 

I have not warmed to the 5mm XW quite as much. The field feels smaller than 70 degrees, and I also see the lateral color on plants.

 

These are quibbles, but if you are looking for the sharpest image on plants, this might be worth consideration. 

The vast majority of widefield EPs show LC, particularly towards the edge. I've never seen or used a widefield EP that didn't have LC near the edges on planets. Even the A11 had LC on planets near the edge.

[areyoukiddingme]

The vast majority of widefield EPs show LC, particularly towards the edge. I've never seen or used a widefield EP that didn't have LC near the edges on planets. Even the A11 had LC on planets near the edge.

 

When you say "near the edge", do you mean at the field stop? At the last ~5-10% of field?

 

I see lateral color in the XWs on planets when the object is about half way between center and edge. 

 

I agree that it is there in all widefield eyepieces. I have not not seen it. But what I have seen is that the degree of lateral color and how bright it is varies.

 

In the XWs, the lateral color is bright reds and blues. In others, it's more muted light yellows that are more difficult to perceive. 

[SeattleScott]

When you say "near the edge", do you mean at the field stop? At the last ~5-10% of field?

I see lateral color in the XWs on planets when the object is about half way between center and edge.

I agree that it is there in all widefield eyepieces. I have not not seen it. But what I have seen is that the degree of lateral color and how bright it is varies.

In the XWs, the lateral color is bright reds and blues. In others, it's more muted light yellows that are more difficult to perceive.

Ernest did note this in his evaluation of the 7XW, and suggested the 7SW might be a better option as a result. Which was a factor in my going with the Nikons over Pentax. That, and the difference in form factor of the 5mm’s.

[areyoukiddingme]

The form factor--long and bulbous--on the 5mm does bother me a tad too. The 7 is fine, and I really like the views.

[25585]

I use Baader Morpheus 4.5mm and 6.5mm, preferring both to the XW and Delite.