EPs and performance rating

I have a question.
When you read reviews and articles about EPs, isn't it interesting how the reviewers will understate the fact that the EP has a soft edge at 20%. They will say how wonderfully crisp the on-axis is as a point of reference and down play the poor 20-30% where the image quality falls off. In the same breath, I have read where the comparison to better EPs stated that this was not a concern, because on-axis was the most important factor.
My question is, why is the off-axis performance not a concern? Why is it OK for a lessor cost EP to have poor off-axis performance where an expensive EP must perform to a much higher standard? Is it really correct to apply this double standard when evaluating EPs. This leads to the old statement "Good for the Money" which is always a problem for me. The EP is either good or bad or in between, but money is not the consideration when evaluating products is it?
So, is a $50 EP a better deal with a 20% soft edge and other aberrations than a $100 EP with 5% or less?
Should an EP that performs well at f/10 but poorly at f/4.3 be rated as very good or rated as good at f/10?
Where exactly do we draw the line between cost and quality?
Just food for thought, what is your opinion?

I think that price should be left out of the comparison. Even when money is a consideration, which is not always the case, what constitutes a meaningful price difference will vary from person to person.

As for the off-axis softness, purpose matters. For planetary observation it is appropriate to weigh it less than with DSO observation. It matters some (e.g. with lunar observation) but not as much. On the other hand, for DSO observation, particularly for open clusters and such, edge sharpness matters for multiple reasons. For one thing you're using scotopic and averted vision and for another the object itself may be spread out. For example, if you're sketching, you'd probably like to have the option of not panning. Consequently edge sharpness should be factored in accordingly for DSO observation.

You win the head-to-head if you're better for the intended purpose, even if you cost 10 times as much. It's challenging to write a review that communicates performance differences in such a way that people can factor in the price differences for themselves, but this is what the author should try their best to do, IMO. It's okay for them to communicate their personal assessment of price versus performance, but it should be done in the conclusions section in a relatively isolated way rather than applied throughout.
--
Mike

I think reviewers should concentrate on the describing the
circumstances of the test (type of scope, F/, type of
object viewed) and their results. Opinions like "good
for the money" etc., also have their place, but are not
a substitute for hard information on the performance.

It is a very complex subject, and ultimately one probably
needs to do the test one's self in your own scope and
own opinions of what is important. But, of course, one
can get some general picture from published reviews.

Camera lens tests are a much simpler problem by
comparison -- there are no other opics, and the target
is some standard sized piece of flat film. The
eyepiece, instead, interacts with aberrations in both
the scope and eye, so will be more difficult to provide
an overall assessment.

There are also unit-to-unit variations, which can cloud
the conclusions. I have seen these highly scientific
camera lens tests produce significantly different
results on two samples of the same lens. It casts
some doubt on the whole review process.

Maybe in addition to providing what objects viewed and focal length of telescope someone should come up with a "blind taste test" for eyepieces. Build a cardboard box around the focuser so the observer can see the EP, but still see through. Then we will know who likes pepsi better than coke. Only then will you get a truly unbiased opinion. I know if I compared a $80 wide field with one of my naglers and the image was better in the lesser I would be throwing up all sorts of excuses and scenarios in my subconscious as to why my nagler was not performing well that night. :S

Todd

As a consumer, I think the "for the money portion" of any review is most critical. From what I've read in reviews in forum posts and experienced as a beginning observer so far, it looks like there are a few eyepieces that hit sweet spots in terms of excellent performance versus competition within their price range. Eyepieces like Orion Explorer IIs, most Paul Rini eyepieces, Siebert eyepieces, and University Optics Kellners come to mind. Reviewers and posters seem to like what they get for the money with these EPs. I like learning about those less expensive deals and the tradeoffs I'll be making when I take them versus a premium eyepiece

Why is it OK for a lessor cost EP to have poor off-axis performance where an expensive EP must perform to a much higher standard?

Polish time on lens = $ It takes more time olishing to get a good edge so the cost goes up. I think they know that a $50 eyepiece will not have a real sharp sharp edge like $200 eyepieces.

The EP is either good or bad or in between, but money is not the consideration when evaluating products is it?

If the review is for one that costs over $120 I just skip over it. I know I will not be buying it. I run slower scopes for a reason cheaper eyepieces.

So, is a $50 EP a better deal with a 20% soft edge and other aberrations than a $100 EP with 5% or less?
Should an EP that performs well at f/10 but poorly at f/4.3 be rated as very good or rated as good at f/10?
Where exactly do we draw the line between cost and quality?

I never really trusted reviews much anyway. You would be better off going to a star party and put it to a test.

Steve