I'm not sure if the 50mm/38.5 fl lens would be a good choice. I believe what makes the lens a really good thrower has to do with the center thickness. I have another lens that is in the 60mm+ diameter, with a relatively short fl, but it's center thickness is not much. It does focus the light, but not to the really tight projection like my current 52x37 fl lens.
I just measured my 52x37mm lens and it has a center thickness of 23mm. The 50x38.5mm lens has a center thickness of 20mm. The only lens that seems to have a better center thickness is the 52 x 33mm lens, which is 25mm.
I'd love to order and try them both, but I don't know what I'd do with them if they don't work out :shrug: I appreicate your offer, though :wave:
I am going to have to respectfully disagree that what makes the light a good thrower is the "center thickness" known as Tc. What is going to collect more light into a more concentrated area in a configuration such as this is the F-number and the focal length. The 50x38.5mm has a higher F-number and focal length (even though the Tc is smaller). I may be wrong, but using lenses of this type is new enough that I think trying other options would be best.
Is no one else interested in testing this? The lens costs $28, I'll pitch in $10 to anyone who would be willing to test the lens and post results. Will anyone else pitch in $5 or $10 to have this lens tested as well??
From other sellers, they have 50mm diameter lenses with 35, 38.5, 39, 42.5, 49, 55mm focal lengths. For the 52mm, I've only been able to find 33 and 37mm focal lengths. There has to be a reason that there are so many different focal length versions for the 50mm. Another manufacturer of aspheric lenses has info on sizes available here:
http://www.optarius.com/dl-asphcond.pdf
I just figure that testing the longer focal length is worth the time. If it doesn't perform up to your specs and you don't want to keep it - put it up for a CPF auction and donate the money to CPF. That solves the issue of what to do with them if they don't work out.
We're trying to do the exact opposite of what the aspheric lenses are for - so it's hard to tell what will work best without testing. I don't know what the focal length of your 60mm lens is, but you are basing the idea that center thickness provides the best results by comparing only 2 lenses of similar diameter and focal length. The 37mm focal length works better then the 35mm focal length, so why not try the 38.5mm focal length.
Now that is very interesting. I have a mag 2C here in which my 50/35 JUST barely fits inside the head. It drops about 2mm down and rests on the inside edge of the head. I don't need to put in a UCL or the reflector for it to sit on.
As you can see in my photos, the lens fits in perfectly. Of course, this is NOT the head I'll be using so it's possible this solution won't work on the head that I receive from Mirage Man.
That looks very good - it seems like the fit is very nice. Hence, why I wish someone would try the 50x38.5mm lens. It seems that the 50mm lens fits in perfectly with the host, hence my desire to get a 50mm lens which works best.
Since the 52mm x 37mm lenses are no longer available from the Surplus Shed, for me to test the 52x37mm against the 50x38.5mm - I would have to buy both lenses for $56...hence why I am willing to donate $10 to the testing (hopefully a couple other people will do this as well). If the lens doesn't perform up to the same level as the 52x37mm, I'm sure someone would still use it - so we can auction it off and the proceeds go to CPF. If the lens does work well, then the tester can just keep the lens.
Who is with me?? :twothumbs - anyone with the 52mm x 37mm lens who would like to test the 50mm x 38mm just PM me your PayPal address and I will send the donation money to support the testing. At the very least, CPF will get $25-$30 out of the whole thing when we auction it off later (or the tester gets the great new lens).
