4mm Eyepiece recommendations for heritage 130p

[AstroJon]

I've been doing some more planetary viewing and was thinking that a 4mm eyepiece might a good idea for when conditions allow, especially now that Saturn and Mars are visible. I'd also use it for lunar observing too.

I've noticed that FLO have a Vixen NPL for £35 and various others for not much more. I don't want to spend more than about twice this as it will only get used on this scope.

Is it worthwhile getting a 4mm (or maybe even 3.2) eyepiece for this scope and if so what would be a good choice?

[rwilkey]

Hi AstroJon, the Vixen NPL would be a good choice, but I cannot help thinking tnat a 4mm might be pushing it a bit, though on paper it is within the scope's capability (4mm = 162x).  The scope focal ratio is also f/5 which means it's more suited to widefield views.

[alan potts]

I think at the magnification of X162 which Robin has kindly worked out you will be OK. The image will be a fair bit dimmer with this amount of power and I would not go higher myself. I use my little 70mm refractor at full tilt with a 3mm regularly and on things like the bright planets and the Moon you should be fine

[ronin]

The NPL is a plossl and I would not like to put a 4mm plossl in anything.

Take a look at the planetary (Celestron or Skywatcher ??) from FLO, or the planetary's from TS.

After that only the higher price ones come to mind, I think the Vixen SLV is around £120-130.

ES and TV being the next.

Antares used to do something in the 4mm region, their W70 eyepieces, but they were not sort of 4mm but 4.3mm or something like that. I should know as I have one somewhere, actuall have 3 of them somewhere, just not sure where the somewhere is.

I have a 4mm planetary and a 5mm BST, rarely use the 4mm mainly as the 5mm is a lot more comfortable and performs better. The increase in magnification is simply more then negated by the better image and the comfort.

I do wish that the BST's came in a 4mm and 6mm offering as well as the 5mm.

One aspect often overlooked is that going from 5mm to 4mm sounds small but it means a 25% increase in magnification, which is quite a jump.

[alan potts]

Ronin,

It sounds like you have 3 of them somewhere in Cambridge. I had a couple of the Antares range too, I am not sure they make the same range now though, T Services used to stock them.

Alan

[AlexB67]

I've not tried 4mm for a while in the Heritage,  I did so in the past with a 8mm BST and a barlow and did not think the results were always that great as this combo produced a slightly "soft" image and not the greatest contrast, more to do with my barlow though to be fair.

The BGO ortho I have at 5mm works wonderfully well at 130x in this scope, but many will not like it due to tight eye relief and small FOV, but  orthoscopics produce such a wonderfully bright image with excellent contrast and sharpness I am happy with that sacrifice on many a night given the views it provides in the heritage ( and barlowed it to 1.5x with surprisingly good results too). 

At that mag the FOV I find quite wide anyway, I use it in the 10 inch Dob to give 240x with a lot smaller FOV and get by, though I would not dispute the fact that it is not your nice widefield long eyerlief relaxing experience, if that is what you want look elsewhere  . The 5mm BGO or equivalent astro Hutech will have tight eyerelief, but not as tights as the NPL 4mm, I would say that must be getting near on unusable. 

With regards to the magnification in the heritage, it  also depends what you are looking at, on Mars I've been able to push the Heritage well over 200x on a couple of occasions with some very pleasant results this year, that was under rather excellent seeing though. Lower contrast objects such as Saturn I find 130 - 160  works nicely, as does Jupiter, it all depends on the night.   When you are fighting for every little bit of contrast in a small scope these high contrast good eyepieces do help IMHO.  The long and the short of it, I would say there is room for a 4mm for that scope. I've use a pentax XW 7mm with a very cheap 2x barlow as a 3.5mm too on a view occasions,  again with some very good results on Mars and Jupiter, and of course the moon.

In the end magnification can be a bit of a personal thing, but if increasing mag helps you see new things and finer features it works for me, that's my motto anyway. If the increase in magnification just starts washing out contrast and sharpness to the point where it does not allow you see anything better, it stops working.

The Heritage 130p is quite a capable planetary instrument IMO with a good eyepieces. I can compare it to my 10 inch Dob so I know about that difference, and that little puppy has really surprised me on a number of evenings this year of good seeing. Until more recently having more eyepieces and combos to try, and getting quite a bit of planetary practice under the belt this year and last, I did not realise how much can be squeezed out of that little scope. 

[AstroJon]

Thanks for the replies. I should have mentioned I do have the BST 5mm and it has seen a fair amount of use. There have been times though when I've felt I could have gone higher than 130x. As someone mentioned, it is a surprisingly good scope and the only thing I'm really lacking is a high magnification eyepiece.

Since every observing session I've had this year has been around full moon I suspect this eyepiece might also see a lot of use :-)

[bingevader]

How about an 8mm and a barlow?

An 8mm plossl would be much better in terms of ER than the 4mm and you'd be able to use the barlow on some of the other EPs you have too?

[IanWatkins]

Can't help thinking a 4mm plos would be a little much in even really good conditions. Just a little much?

[AstroJon]

I agree, a 4mm plos would not be a good idea.

I have actually considered the possibility of an 8mm and a Barlow, although that would further erode my funds towards a bigger scope. I am lacking something in the 8-12 range but I had originally planned my eyepieces without a Barlow and currently have a 5mm, 16mm and 24mm.

At the moment I'm interested by the TS Planetary HR 4mm for £49 but I won't be getting anything for a few weeks so that will give me time to have a look round. If I see a decent barlow and 8mm second hand then I could be tempted.

Thanks for the advice so far.

[bingevader]

An 8mm and a barlow would give you a 12 too, combined with your 24mm. 

[SW130p]

I have the 8mm BST and use it with a BST 2x Barlow with great results with my 130p you get two eyepieces in one. I have also got the BST 5mm to use on its own, I have used it with a Barlow at 2.5mm but unable to get focus. But I now have a new mount an Heq5 and a electric focuser and with that the other night I tried it again and was amazed I could focus on Saturn I could clearly see the gap between the rings and a bit of detail on the planet.

So with a lot of magnification you need to make sure your scope is sturdy.

5 and 8mm is good range to have with your scope.

Sent from my iPhone using Tapatalk

[Schorhr]

I have the HR Planetary which are remotly similar to the bst AFAIK.

8, 3,2 and 2,5mm.

I guess I am a lucky duck and even with the 2,5mm I can focus, unfortunately mirror qualit of the 130p seems to vary.

The HR Planetary are relatively cheap, 40gbp or so.

But if you have the 5mm bst already and if those are similar:

Does it have a bottom lens element that you can unscrew?

If so, consider the Astrozoom.de adapter. I know I sound like a sales representative but it's a neat tool :-)

I use it with my 8mm and I get an effective focal length of about 3,5-7mm or so.

If you like to tinker you could just fimd another way to change the tube length/distance.

On another note, I have a 4mm Plössl, the eye relief is horrible making them almost useless and at high magnification the narrlow field of view becomes an issue. Also with cheap barlows you might just lower the contrast, resulting the barlowed planetary image in showing less then with the 5mm...

[AstroJon]

I've just checked, the 5mm does indeed have a bottom lens element that can be unscrewed. I'll check that adaptor out, that is something I wasn't aware of. Thanks!

I'm impressed that people are managing to get views with 2.5mm. I do seem to remember seeing the BST barlow some time ago but doesn't seem available anymore? Having said that, I am now giving consideration to barlow due to the advice above.

So thats either the 4mm planetary or an 8mm and a barlow. I don't think my wallet will forgive me if I get all 3

[The Flinty Fox]

Just thought I'd add that I have recently brought a 4mm university ortho from ebay and I think its great. Was a bit worried about eye relief but found it surprisingly comfortable to use and gives great views. Saw the cassini division using it last night and only cost £30.

Paul

[The Flinty Fox]

Forgot to say this was in my 150p.

[YKSE]

Just thought I'd add that I have recently brought a 4mm university ortho from ebay and I think its great. Was a bit worried about eye relief but found it surprisingly comfortable to use and gives great views. Saw the cassini division using it last night and only cost £30.

Paul

If you can cope the short eye relief, orthos are the eye pieces for the planetary viewing, especially considering the cost.

[Schorhr]

I suppose it is a matter of taste, other then the short eye relief of the short focal length plössl those are nice, too, the 4mm did cost 6gbp new ;-) I find the short eye relief eyepieces and narrow field eyepieces better with a tracking mount/plattform. 

I've just checked, the 5mm does indeed have a bottom lens element that can be unscrewed. I'll check that adaptor out, that is something I wasn't aware of. Thanks!

I'm impressed that people are managing to get views with 2.5mm. I do seem to remember seeing the BST barlow some time ago but doesn't seem available anymore? Having said that, I am now giving consideration to barlow due to the advice above.

So thats either the 4mm planetary or an 8mm and a barlow. I don't think my wallet will forgive me if I get all 3

The 8mm Zoom will give you all of the above and more if seeing is great, so it is defenately worth a look. I was luxky and got mine used :-)

I have read of one case where someone was not able tp get focus on anything above 100x, so the heritage mirror quality really varies greatly or the person did not collimate well.

If you are into tinkering you might just change the eyepiece element distance and see if the magnification is higher and if it works.

Basically like the distance rings for some  baader eyepieces.

[YKSE]

I agree, a 4mm plos would not be a good idea.

I have actually considered the possibility of an 8mm and a Barlow, although that would further erode my funds towards a bigger scope. I am lacking something in the 8-12 range but I had originally planned my eyepieces without a Barlow and currently have a 5mm, 16mm and 24mm.

If you don't wear glasses, another solution might be BCO 10mm with QT barlow 2.25x, which can also be screw on an EP for 1.3x, this combination will equivalent 4mm, 7.7mm and the original 10mm. £49 for an excellent EP is a steal to me.

http://www.firstlightoptics.com/baader-planetarium/baader-classic-ortho-bco-eyepiece.html

Here's the review by John "the mod", if you haven't read it:

http://www.firstlightoptics.com/blog/baader-classic-ortho-plossl-review.html

and reviews on CN

http://www.cloudynights.com/ubbthreads/showflat.php/Number/5604386

If I'm not mistaken, ThomasM there is the late Thomas Back, who invented the TMB planetary (HR planetary are clones), Paragon (SW AERO are clones) eyepieces.

[YKSE]

Find some typo above, should be

"this combination will give equivalent 4.4mm, 7.7mm and the original 10mm"

[AndyWB]

FWIW, I have used the 8mm BST x2 barlowed in my 130p for a bit more magnification than the 5mm BST gives. I've only used it on planets, and it did prove useful under very good conditions - but given how rare that's been feasible, well, I wouldn't invest in a 4mm EP for those 2 or 3 occassions in the last 18 months.

[AstroJon]

Thanks again for all the extra advice. From my experiences with a 5mm I am aware that a 4mm wouldn't get a great deal of use but there have been several times when I've felt that I could get more magnification and if I could get something that would give a reasonable view for relatively cheap then for me it would be worth it.

I have seen the BCO reviews and I am lacking something in the 10mm range, a 2.25x barlow that could also be used at 1.3x along with the 10mm is a very interesting option!