Why big difference between Megascope and AGS cert? HCA scores differs greatly! Help!

[auroraorangey]

Hi guys, I''m looking at this stone http://www.goodoldgold.com/diamond/3672

The megascope puts its table % at 55.6% thus getting a HCA of 2.1.
The helium and AGS cert states the table % as 56.3% and 56.2% repsepctively, getting a 1.3 and 1.4 on HCA respectively.
I can understand the limtations of technology, so it''s alright for helium and AGS cert to have slightly different measurements. But the megascope''s measurement is worrying me. The HCA score is not as pretty.

Pls help!

 

[JulieN]

helium is going to give better numbers than megascope.

Ideal Scope looks great.

 

[auroraorangey]

Julien, thanks for the reply.

Any idea which is more accurate? I read that megascope and sarin are more accurate as compared to the rest? If that''s the case, AGS cert and Helium has abt the same numbers. Does it mean the cert isn''t as accurate? Perplexing!

 

[JulieN]

helium. each machine is different. but megascope? eh, I never look at that.

 

[Regular Guy]

I believe megascope is based on ogi, which has a different basis for measuring, and is not regarded near so well as either sarin, or helium, which is better yet. AGS use sarin typically.

Also...2.1 not so bad, anyway.

Anyway, regardless of the imputed measures...the 0 for light performance trumps the HCA calculation largely, also.

 

[strmrdr]

The helium numbers are the most accurate followed by the ags and sarin with the megascope a distant third.

 

[strmrdr]

That diamond was just discussed in another thread, Its kicken, I have looked at it for a pendant stone for my sister if it was still available when I get working again and some money ahead.
If you dont mind the L color its one kicken stone.