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Short focal length EPs with glasses


SteveBz

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Hi Guys,

I have a small collection of cheap EPs and glasses.   I'm slightly short-sighted with astigmatism.

It seems to me that if I don't wear my glasses it looks like my telescope is not well collimated.  If I wear my specs I can use a 20mm Plossl or Kelner, but not the shorter focal length lenses (Huygens, Ramsdens and Kelners). 

While it's obvious I need to upgrade my eyepiece collection, there is not much point in doing so if I have to remove my glasses.

What do you think?

Thanks

Steve.

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Hello Steve , it sounds to me if you are in a catch 22 situation. You could do with better eyepieces but you do not want to buy incase you waste your money buying eyepieces that are not suitable for your eyes 

The best advice I can give you is try before you buy to see if certain eyepieces will work for you and give you better images therefore warrant the expense. I there suggest going along to your local astronomy club or booking up on one of the SGL parties or similar. And the chaps and ladies I am sure will have a range of televue, William optics , explore scientific ect ect for you to try in your scope and see if they are an improvement and suitable for your own individual needs. Then you can make a note what works for you and what doesn't. And then make a purchase on the eyepieces that are of benefit to you and therefore have confidence in the money you are spending upgrading your eyepiece collection is money well spent.

I hope the above helps☺

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I agree with TB - above - to try before buying. Look for a local astronomy-club that has outings. Go to at least one such event and talk to members and ask to see what their eyepieces are like for you. Members wearing glasses would be a BIG +!

This should set you on the right path.

Dave

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51 minutes ago, SteveBz said:

Hi Guys,

I have a small collection of cheap EPs and glasses.   I'm slightly short-sighted with astigmatism.

It seems to me that if I don't wear my glasses it looks like my telescope is not well collimated.  If I wear my specs I can use a 20mm Plossl or Kelner, but not the shorter focal length lenses (Huygens, Ramsdens and Kelners). 

While it's obvious I need to upgrade my eyepiece collection, there is not much point in doing so if I have to remove my glasses.

What do you think?

Thanks

Steve.

You just need to look for eyepieces which have good eye relief, and which maintain it down to the lower focal lengths unlike plossls etc

A good example would be the Vixen SLVs, 20mm eye relief through the range, 50 degree afov and orthoscopic type performance, could be ideal for you?

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You don't need to spend a fortune for eyepieces if you're not after very wide FOV.

As Stu mentioned above, SLVs are very good, 7mm and 9mm X-cel LX should work very well with your scopes too with 60° FOV (the 7mm are actually 62.4° FOV :smiley:)

https://www.firstlightoptics.com/celestron-eyepieces/celestron-x-cel-lx-eyepiece.html

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Or save some money and get used Vixen LV/NLV or Pentax XL eyepieces.  I have a 9mm LV and 5.2mm XL and find that they give up nothing to the newer Delos and XWs except for AFOV and slight transmission/contrast differences.  Sharpness to the edge and freedom from glare/ghosting are basically equal.

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The Pentax XL's (and their successors, the XW's) are really excellent but they seem to cost more used than the Vixen SLV's do new, in the UK.

The Vixen LV's and NLV's were the predecessors to the SLV's and are worth looking out for.

 

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41 minutes ago, John said:

The Pentax XL's (and their successors, the XW's) are really excellent but they seem to cost more used than the Vixen SLV's do new, in the UK.

The Vixen LV's and NLV's were the predecessors to the SLV's and are worth looking out for.

 

 

I agree. The vixen NLV is a very nice eyepiece with great eye relief and afov around 45d , but because of the comfort of the eyepiece and eye position to me it just feels more. I have recently brought this on an impulse buy to try ,and initially my thoughts in my frac are they are very good ,sharp to the edge and comfortable eyepieces to use . I understand the NLV are Japan made and the more recent replacement are the SLV. So the NLV IMO is a very good eyepiece and I have no regrets in this purchase and as it was purchased  used I got a very good price on it , I won't say how much as may get tomatoes and cabbage thrown at me ?.  But a very nice eyepiece that is well worth considering 

 

 

IMG_20160816_111731.jpg

I hope this helps☺

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1 hour ago, John said:

The Pentax XL's (and their successors, the XW's) are really excellent but they seem to cost more used than the Vixen SLV's do new, in the UK.

The Vixen LV's and NLV's were the predecessors to the SLV's and are worth looking out for.

 

The XLs cost $220-$240 new 17 years ago when I bought mine.  The LVs cost $90-$110 new back then.  Of course the used XLs are going to cost more used than the SLVs new.  They are 65 degrees vs 50 degrees, Japanese made versus Chinese made, etc.  I'm not really following why you'd expect them to cost less.  Used eyepieces generally sell for 60%-65% of new.  If you had said used XLs are selling for more than new Vixen LVWs, then I would be surprised, but they aren't.  That would be an apples to apples comparison (65-65, Japanese-Japanese).

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41 minutes ago, Louis D said:

The XLs cost $220-$240 new 17 years ago when I bought mine.  The LVs cost $90-$110 new back then.  Of course the used XLs are going to cost more used than the SLVs new.  They are 65 degrees vs 50 degrees, Japanese made versus Chinese made, etc.  I'm not really following why you'd expect them to cost less.  Used eyepieces generally sell for 60%-65% of new.  If you had said used XLs are selling for more than new Vixen LVWs, then I would be surprised, but they aren't.  That would be an apples to apples comparison (65-65, Japanese-Japanese).

Just to clarify, my point was made because previous posters had been recommending Vixen SLV eyepieces which cost around £120 new in the UK or around £70 used and then you posted "Or save some money and get used Vixen LV / NLV or Pentax XL eyepieces...." which prompted me to point out that used XL eyepieces cost more than Vixen SLV's do new, at least in the UK. So no money would be saved selecting XL's over SLV's. The older NLV and LV series eyepieces are a little less expensive on the used market than SLV's. LV's light transmission rates are not as good as the later ranges though.

LVW's are a very nice Vixen range as well but their price is a good step above the SLV's both new and used.

The SLV range don't seem to have suffered one iota for being made in China rather than Japan. Both their optical and build quality is a touch better then their Vixen predecessors, IMHO.

 

 

 

 

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'...the Vixen SLVs, 20mm eye relief through the range, 50 degree afov and orthoscopic type performance...'

I have seen similar praise for the SLV time and again on this site, I'm surprised they're not more popular/well known. Considering all the (deserved) praise heaped on eyepieces such the TeleVue Plossl range, and the benefits over them that the SLVs offer, I'm also surprised that the SLVs are not the benchmark for 50 degree field eyepieces. I've had NLVs and SLVs in the past (and like many other EPs, I've foolishly sold them on!), and I'm very tempted to get some more.

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I have 1.5 Sph and 1.0 Cyl for my right eye. I have  found my BST Starguiders to be  comfortable in use, with  a decent  amount of eye-relief, they have a large eye-lens, and an effective field of view of 60°, yet I choose not to wear my glasses at the scope?
When I just look at the Stars, I see them better with glasses on, so they do work, and focusing the telescopes eyepiece alone,  deals with the short sight, without glasses,  but I still may have to consider astigmatism. At present my images look ok, but I need to test some more, and maybe look further afield than just on axis!

I have obtained some Delos eyepieces, which are still awaiting the right conditions and a  darker site to give them a proper assessment. On paper they should better my Starguiders, but my first views tell me only the field of view differs? the image still looks the same, but I have not looked through Delos wearing glasses, with their 20mm eye-relief, so wearing my prescriptions with the Delos, just might produce a 'better image'. TeleVue has their  Dioptrx lens system, "better than glasses " according to the reports?

I'm not suggesting go out and buy TeleVue, but it is a matter of just trying to find what works best for your needs. My BST's are great, what if the Delois prove to be better?

You mentioned Plössl Eyepieces, their eye-relief diminishes  as you progress towards the shortest focal length, to about 70-80% of the focal length, which can be  uncomfortable for some folk.  I found the 8mm TV Plössl uncomfortable, yet find another 6mm Plossl  more usable? Its down to the eyepiece and the end user.

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6 hours ago, John said:

 

Just to clarify, my point was made because previous posters had been recommending Vixen SLV eyepieces which cost around £120 new in the UK or around £70 used and then you posted "Or save some money and get used Vixen LV / NLV or Pentax XL eyepieces...." which prompted me to point out that used XL eyepieces cost more than Vixen SLV's do new, at least in the UK. So no money would be saved selecting XL's over SLV's. The older NLV and LV series eyepieces are a little less expensive on the used market than SLV's. LV's light transmission rates are not as good as the later ranges though.

LVW's are a very nice Vixen range as well but their price is a good step above the SLV's both new and used.

The SLV range don't seem to have suffered one iota for being made in China rather than Japan. Both their optical and build quality is a touch better then their Vixen predecessors, IMHO.

 

 

 

 

I'm sorry I misunderstood your statement.  My thought was that if you're going to spend $170 on a new Vixen SLV, you might as well spend the same money on a used Pentax XL and get a 65 degree vs 50 degree field.  Perhaps the two prices aren't as comparable in the UK.  I rarely use my 9mm LV compared to my XLs, XWs, Delos, or Morpheus eyepieces mostly because of its restrictive field of view.  When I do use it, I am still impressed with just how good it really is.

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Thank you to everyone who replied.  The reality is I'm not going to get much for less than £50 per eyepiece, say £150 if I buy three.

Might I not be better served if I moved up to 2" eyepieces?

Once you get past the cheap 1.25s they seem to be about the same price.  I may just get more quality that way.  The only downside might be that I couldn't migrate back to a 1.25 scope:  as I've mentioned before, that c8n can get mighty heavy.  The problem is that the CG5 is such a nice mount, it would be a shame to have to move back to the EQ3.

So 2" anyone?

Regards

Steve.

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2" eyepieces are only really relevant for wider fields of view which will not fit within the barrel size/field stop of a 1.25". A 2" eyepiece is not by definition better quality than a 1.25", it just gives access to the wider views.

At higher powers, you need to look for the qualities we have discussed such as the optical quality in terms of sharpness, contrast and light scatter, plus the required long eye relief to allow you to use your glasses comfortably.

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As Stu says, no advantage to the 2" format until the focal length gets longer than 18-20mm when the wider 2" barrel can provide a larger field of view than a 1.25".

The BST Starguiders that Stu links to above are pretty good for sub £50 eyepieces and have quite good eye relief for glasses wearers as well.

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If you can get your exit pupil low enough, you can take those glasses off. I have the same issue as you, but I noticed if I get the exit pupil down to around 1mm -  1.25mm  give or take a little I can take my glasses off and it is wonderful. Of course your mag will be up there. As long as your scope and seeing can handle 1x per millimeter of your objectives diameter, you should be golden on that.

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As an astigmatised glasses wearer I know everything you are going thropugh. EP's i have tried which work very well with glasses are as follows:

The vixen range throughout and all perform very well. LVW give you some extra FOV but are more expensive but all perform well.

Celestron X-Cels, i used these for a fair while before upgrading from them and have to say they performed well too. Not as good as vixens but very acceptable.

Baader hyperions worked ok but they are not as good in faster F5 scopes so not really recommended

Delos worked brilliant but not cheap, eye relief superb.

Radians as above but these are only available 2nd hand now.

Pentax XW. I think these were ok but the delos beat them as they seemed better for me when wearing glasses.

There have been several others which have all been ok ish but i never really got on with the ES range that well.

Basically eye relief is the key factor although keep clear of cheap options, you get what you pay for.

I now use the eyepieces in my signature (far from cheap) but i couple these with a televue dioptrx which cure the astigmatism and does away with the need for glasses.

HTH

Steve

 

 

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