Speed Panchro 75mm S2 // S1 ???

[Deniz Cooper]

Dear friends,

I have a set of Speed Panchros S2 and S3.
(still searching for a 50mm S2 btw - if you have one for sale, please let me know!)

I found a really nice guy who has two 75mm lenses:  One series 1 and one series 2 lens.

At first I thought, it's clear and I take the series 2 lens, it will fit better into the set.
But the glass has a lot of yellow and there are zwo small 'bubbles' in the front glass.

That's why I would like to ask you: Is there any reason why I should prefer the series 2 lens?
Does it have a bigger image circle / better coverage? Is the glass of the series 1 #worse' than the one of series 2 etc.?
Please let me know if you have any thoughts about that. 
Thank you very much! ?

[Scott Sorensen]

I was in a similar situation with the 100mm Panchro not long ago. As I understand it, the main difference between the S1 and S2/3 lenses is the coatings. The S2 75mm will match better with your existing kit. Ultimately, I passed on a S1 100mm and waited a year for an S2 to come up for sale.

As for the S2 you're looking at, the 75mm is known to yellow over time. TLS has a process that can slightly de-yellow the 75mm- I had it done to mine when I had it rehoused. If you have some photos of the glass, you might send them to the folks at TLS to get their take. They may be able to advise you as to whether or not the lens is worth picking up.