Hi Dan,
I'm considering that there should be a variability in performance(marginal) among patches of lenses of the same model/design from the same manufacturer, as well as individual variability in performance among lenses of the same patch No. This is valid for brand new lenses.
For used lenses, the variability in performance, should be wider(due to misuse). But I'm neglecting all of these variabilities & assuming both lenses are new(Only, as a base line comparison). And after all, its the performance on film which should counts.
![Quote](images/misc/quote_icon.png)
Originally Posted by
Dan Fromm
Thalmees, the Vade Mecum makes the point, and strongly, that the big jump in lens performance in the Symmar line came when the Symmar-S replaced the Symmar with no suffix (sold as a convertible lens). It argues that after that the improvements from version to version were very small, possibly nonexistent.
Chris is too modest to direct you to his and Kerry Thalmann's lens tests. Basically, their tests support three useful ideas:
(a) used and some new lenses of the same make and model vary in performance.
(b) newer lenses in a line ("Symmar", "Sironar", ... ) don't always perform better than earlier versions. This may be a consequence of (a) and small samples of lenses.
(c) it is hard to buy a large format lens that isn't good enough.
From all of which I've concluded that the thing to do is buy a lens, when one is wanted, with the right of return and run it through acceptance testing. If it flunks, sent it back.
I think you were asking whether the cells of a lens in DB mount can be put in a shutter. Yeah, sure, why not? Especially for the lenses you're considering, both of which go into #1 shutters.
Q3? No need to recalculate, get the wretched things and measure for yourself. Note that calculating what the bits do requires lens design software and the lens' specifications -- glasses RIs and dispersions, all radii. These are rarely easily found.
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![Quote](images/misc/quote_icon.png)
Originally Posted by
Dan Fromm
From all of which I've concluded that the thing to do is buy a lens, when one is wanted, with the right of return and run it through acceptance testing. If it flunks, sent it back.
Each lens came with separated cheap F2 kit BTW. I'm already owning the lenses.
![Quote](images/misc/quote_icon.png)
Originally Posted by
Dan Fromm
I think you were asking whether the cells of a lens in DB mount can be put in a shutter. Yeah, sure, why not? Especially for the lenses you're considering, both of which go into #1 shutters.
I was asking whether the cells of the shuttered(broken) lens can be put in the DB mounted board. And from your response, it looks to me possible. Thanks.
![Quote](images/misc/quote_icon.png)
Originally Posted by
Dan Fromm
Q3? No need to recalculate, get the wretched things and measure for yourself. Note that calculating what the bits do requires lens design software and the lens' specifications -- glasses RIs and dispersions, all radii. These are rarely easily found.
Clear message Dan. Thanks.
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Dan, I appreciate your contribution here.
Best wishes.
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