Hi 

I am trying to get some clarity (yes - sorry about the pun) about the correct corrective lens prescription for my new Crystal Light.  There is confusion about the correct prescription of glasses to wear or corrective VR lenses to purchase.  

I have: a hunch; some hints of confirmation that my hunch is right; results of some extensive experiments I have done on my own headset which I outline below.

But have any other glasses wearers had blur issues? 

Just as importantly, are any other glasses wearers getting crisp views - and if so, what distance of vision are those glasses or lenses set at (far-distance, mid-distance, reading)?

 

So my non-verified hunch:  that the Crystal Light (and maybe the Crystal too) has a virtual image distance of 1 metre.  Headsets such as the Reverb have a virtual image distance of 2 metres.

And if my hunch is correct, then any glasses or corrective lenses will need a modified mid-distance prescription.  Modified because it may be different to more usual display screen distances of around 600mm

 

My experiments.  But please remember, this is my eyes, my headset, etc..  Without confirmation from Pimax that the virtual image is, indeed 1 metre, then this is still a hunch and not a fact.

 

Start point.  I am mainly short sighted, with a slight age-related long sight issue too.  As such I wear varifocal glasses in day-to-day life. 

Experiment 

• I bought three pairs of glasses, each with a specific fixed-focus prescription:
  • Far-distance
  • Mid-distance, for sharp visuals at typical Display Screen distance of 600mm
  • Modified mid-distance, for sharp visuals at 1000mm
• I tested my Crystal Light in MSFS with a number of aircraft, times of day, weather conditions, wearing each of these three pairs of glasses in turn.  The Crystal Light settings had been optimised beforehand to give the smoothest and sharpest results I could achieve with my hardware

Results

• Wearing far-distance glasses  The Crystal Light was unusable.  Extremely blurred, in cockpit and external views.  Eye strain within minutes.
• Wearing mid-distance (Display Screen at 600mm) glasses    Crystal Light very usable.  Very slight 'soft focus' both in cockpit and external views
• Wearing modified mid-distance (for visual clarity at 1000mm) glasses   Best VR I have personally had to date (and I'm a long time user of VR in flight sims).  Absolutely crisp  images in cockpit and outside views

 

Anyone else experimented?  More to the point, anyone else got definitive information to confirm or challenge my hunch?

Edited October 8, 20241 yr by AJZip

I should add, by the way, that my definition of blur doesn't include the micro-judders I get of the outside view when, for example, I'm turning on the taxi way.  In fact, in some ways that is worse because the clarity is such that I can now see every blade of grass micro-juddering past! 😀 

I'm fast coming to the conclusion that my hunch is correct and that the glasses prescription that is needed is that for 1 metre intermediate distance.

I had an eye test specifically for 1 metre intermediate use and went onto the VR Optician website to order my overlay lenses. And I saw that there is an additional tick box for the Crystal Light that there isn't for, say, the HP Reverb.

Here's the Reverb:

Note is only has one option for prescription and is specific that it is the 'distance' prescription that is needed

 

But the order screens for the Pimax Crystal and Crystal Light have an added prescription option, 'Intermediate prescription':

 

So, were they going to adjust something depending which box I filled in?  So I contacted their Order Support desk to clarify.  This was their answer:

"If you have specific values for mid to close distance as you mentioned please make sure to select 'Intermediate prescription' so your ordered values do not get adjusted. 

When selecting 'Far distance prescription' we will adjust your ordered values to fit the Pimax Crystals image distance."

So they DO adjust the prescription if you enter your Far Distance prescription!  And, actually, if you do tick the 'Intermediate Prescription' box, you get another drop down which is asking whether you have glasses of that prescription and are happy with them while using the Crystal Light.  :

 

VR Optician haven't specifically confirmed that the VR image distance adjustment that they use is 1 metre, but my experiments and snippets elsewhere point that way.

 

Why does this matter?

Because a 1 metre VR image distance, while not unique, is different to the 2 metres of many (most?) other popular headsets

Because there is a lot of confusion and mixed messaging going around, including within Pimax itself. 

Because getting it right makes SUCH a difference to the VR view you get with this wonderful headset.  Remember, even the small tweak I did in my experiments, above, from 600mm intermediate distance glasses to 1000mm intermediate distance glasses made a tangible improvement to the sharpness of view. 

Because there are a number of posts in the wider VR community complaining about blurry visuals on this new headset...and some of them resulting in folks returning the headsets and asking for their money back.  The above may well not be the problem - but it's unfortunate for both the disappointed buyers and for Pimax's costs and reputation if some of those cases are where it's simply the wrong glasses that are being worn...

 

Edited October 9, 20241 yr by AJZip
typo

I just use my typical 1.5 "cheater" reading glasses while using the Pimax CL.

for me the results are very good.

There is maybe a very tiny amount of blurry instruments. Beyond that the readers work fine!

 

Got my VR Optician lenses this morning using my 1 metre intermediate prescription.  Spot on prescription with both the inside and outside views super sharp in comparison to other VR headsets I've used before.  That said, I found it quite sensitive to any adjustment to the headset in use and so I tended to have the straps tighter than I'm normally used to so that my face position didn't move about as I was flying.

 

I’m not a fan of the head strap.
its not very comfortable.

17 hours ago, tpete61 said:

I’m not a fan of the head strap.
its not very comfortable.

I also have the 'comfort head strap' add-on.   Head strap it is, comfort it's not 😀 

It is, however, easier to adjust accurately the height with this.  At the moment, in order to get the headset angled correctly to get - admittedly, crackingly good - clarity, I find the whole set up extremely uncomfortable.  Then again, it took me ages, and lots of fiddling with straps and face cushions, to get the Reverb to the state where I could use it for extended periods of time.

I'm going to invest in some of the Studioform Creative stuff which might help.  I already use their weight pack I've plundered off my Reverb to try it...and that weight does help the balance.  I'll get the specific ones for the Crystal Light so that I can fit them properly.  I then just have to sort that tilt out... 

The stock "tilt" doesn't feel right on my head at all.

My Reverb G2 was more comfortable.

 

20 minutes ago, tpete61 said:

The stock "tilt" doesn't feel right on my head at all.

My Reverb G2 was more comfortable.

 

You have to pull the headset down on your head (loosen the head strap in the back).  The back of the headset padding should touch the lower back of your head where your head meets your neck.  I thought the Reverb was better until I realize I was wearing the CL wrong.

Edited October 15, 20241 yr by Dillon

another reason why I have postponed my CrystalLight purchase and instead will be waiting for this one:

https://en.shiftall.net/products/meganex8k

 

1 hour ago, Dillon said:

You have to pull the headset down on your head (loosen the head strap in the back).  The back of the headset padding should touch the lower back of your head where your head meets your neck.  I thought the Reverb was better until I realize I was wearing the CL wrong.

And you DID say that before...and yet with all of the excitement, lens spec stuff, prescription lenses speccing, ordering, fitting and then trying to get my IPD where it should be and getting the sweet angle and height of the lenses, and, and, and...

...and I CLEAN FORGOT that is what you said!

Those magic words: "The back of the headset padding should touch the lower back of your head where your head meets your neck."

Did that, and it's comfy, and it's in focus and the angle of the screen is right.  And you are right in an earlier post - you lower the whole headset much further than you would expect to.

Bravo, @Dillon Upvote duly awarded 😁

2 hours ago, turbomax said:

another reason why I have postponed my CrystalLight purchase and instead will be waiting for this one:

https://en.shiftall.net/products/meganex8k

 

Looks nice, now what are you going to do about sound...😶

19 minutes ago, Dillon said:

now what are you going to do about sound

same what people who got the Varjo Aero or Apple Vision Pro did. but perhaps they will offer headphones later on. still 1 year until I will upgrade from my HP Reverb G2

Edited October 15, 20241 yr by turbomax

On 10/14/2024 at 10:47 PM, AJZip said:

Got my VR Optician lenses this morning using my 1 metre intermediate prescription.  Spot on prescription with both the inside and outside views super sharp in comparison to other VR headsets I've used before.  That said, I found it quite sensitive to any adjustment to the headset in use and so I tended to have the straps tighter than I'm normally used to so that my face position didn't move about as I was flying.

 

Do you also have the 15mm face foam or do they work without it?

2 hours ago, carlito777 said:

Do you also have the 15mm face foam or do they work without it?

I have the 15mm foam on at the moment as it is a bit more comfortable.  I will try the thinner one at some stage to see if there's enough room.