There has been much written about the use of supplementary lenses - specifically, "Proxars" with Hasselblad lenses. Some is truth, much is not. IMHO, the best "filter" to determine which is which, is to apply the Laws of Optical Phenomena.
Let me respond to some arguments. I don't know of a way to import various "pieces" included in other messages, so I will be typing with ten ham-handed fingers, and I apologize for any inaccuracies in transcription.
Yes, you did. Is there another set of Optical Laws that applies to other lens systems? I only know of one set - can you direct me to others?
... I said, specifically CAMERA LENS...
I take this as an insult. If it is not, please quote the specific statement I made to make this "apparent" to you. I was AGREEING with your statement that additional glass attenuates more light. That agreement was to you, "Not understanding"?
Apparently you don't understand reflection vs. refraction...
Of course not. That was only meant as a single illustration where one auxilliary/ supplemental lens DOES... and I'm glad that you agree that the possibility does exist.
Proxars do not(!) improve quality only because an auxilliary lens over the Hubble does.
No. I have never said there was *no* deteriation effect, or that there was... only that both Proxars AND Extension tubes allow the application of the lens outside of the original design parameters. Whether the effect either has is unacceptable or not is up to the user/ photographer.
You think that Proxars do not have a deteriation effect on Zeiss lanses, because you admire the designers of those Zeiss lenses ...
As fine as the Zeiss/ Hasselblad lenses are, they were not designed to "be the best they could be". Their design was limited by the design parameters, one of which was cost. They are GOOD - damned GOOD - but by no means "perfect". The "best they could be" would have exceeded - by a bunch - cost limits.
... admire the designers of those lenses for having done their best to make them the best they an be, without these cheap, crappy pieces of glass in front of them...
"Cheap, crappy" .... For the moment I'll leave "crappy" alone. "Cheap"? You have GOT to be kidding...
Now - am I mistaken, or were the designers of the Proxars - or at least those who decided their applicablity to the Hasselbad System - the same people who designed the lenses? Or are you suggesting some sort of sabotage from an outside group?
Crappy? I would suggest that the idea "simple=crappy" is not NECESSARILY (let me repeat: NOT NECESSARILY) a carved-in-stone ultimate truth. Most. if not all, of the FINEST camera lenses are composed of finely crafted SINGLE elements, some cemented together.
Now, please refrain from telling me "what I think". You simply DO NOT KNOW what I think. Using that as a tool of intimidation/ domination will not work.
Last edited by Ed Sukach; 05-13-2008 at 08:12 PM. Click to view previous post history.
Reason: $%@ typo ....
Ed Sukach, FFP.
Alll? ALL(!) ... ???
Proxars introduce ALL (!) possible lens abberations (the ones your revered Zeiss desgiers painstakingly designed away), reducing your expensive lenses to the level of some less expensive ones.
Plain beef by-product. They may increase the amount of certain abberations (or may not...) but INTRODUCE??? ALL possible? Certainly you would not include Coma (a possible abberation), would you?
I've never regretted the purchase of my Hasselbad gear - lenses OR Proxars.
So if you think it is a good idea to use these things still, you might also want to remind yourself why you have spent the amount you have on getting good lenses to begin with, and ask yourself which of the two decisions - use Proxars or spend enough to get good lenses -was the silly one.
However, the discussion was about a comparison of Proxars and extension tubes/bellows ...
You do not intend to change the subject ... do you?
You better brace yourself - I do NOT intend to abandon my use of Proxar supplementary lenses - not any time soon. They work *fine*, as far as I am concerned.
Ed Sukach, FFP.