Baader Semi-APO Filter

[bendiddley]

I have a Baader Semi APO filter which came with some stuff I bought recently however it doesn't have "w.IR blocker" written on the side, it just says "Baader Semi APO filter (Optically Polished) # 2458398", are there two types of Semi-APO filters or are they the same? Cheers.

[rwilkey]

Hi there, I have just checked the Wex website and it has this to say at the bottom of the descriptrion page: ' The inclusion of Baader's renowned UV/IR Cut coatings on the Semi-APO eliminate UV and IR wavelengths to make it ideal for high-resolution imaging with Webcams, DSLR, and CCD cameras (see the UV/IR Cut filter below, for more detail on these coatings). The high transmission and fringe reduction work great for both planetary and deep sky imaging.'  Link: https://www.wexphotovideo.com/baader-semi-apo-filter-1552085/

[bendiddley]

Thanks for the info however I still don't know if my one has the IR blocker or not as it doesn't say it on the side. The wex description only says that their one includes this. I am wondering if mine is an earlier version which either does not have the IR blocker coating or does have the coating but doesn't say on the side.

[rwilkey]

21 hours ago, bendiddley said:

Thanks for the info however I still don't know if my one has the IR blocker or not as it doesn't say it on the side. The wex description only says that their one includes this. I am wondering if mine is an earlier version which either does not have the IR blocker coating or does have the coating but doesn't say on the side.

Not sure if that's something that can be answered, but i see what you are thinking.  Perhaps someone else will come along with an answer?

[Stu]

On 25/11/2018 at 10:36, bendiddley said:

I have a Baader Semi APO filter which came with some stuff I bought recently however it doesn't have "w.IR blocker" written on the side, it just says "Baader Semi APO filter (Optically Polished) # 2458398", are there two types of Semi-APO filters or are they the same? Cheers.

I think I remember the Baader Neodymium filter being updated withtge addition of IR blocking at some point, so it's quite possible that the Semi Apo was updated in the same way. If it is not makes on the case, I would probably assume it does does not have the IR block.

[bendiddley]

14 minutes ago, Stu said:

I think I remember the Baader Neodymium filter being updated withtge addition of IR blocking at some point, so it's quite possible that the Semi Apo was updated in the same way. If it is not makes on the case, I would probably assume it does does not have the IR block.

I wondered this. Interestingly the model number on mine (2458398) is the same as the latest ones, which made me wonder if mine is the same but just not with the IR blocker text written on the side.

[Stu]

13 minutes ago, bendiddley said:

I wondered this. Interestingly the model number on mine (2458398) is the same as the latest ones, which made me wonder if mine is the same but just not with the IR blocker text written on the side.

Hmmmm, curiouser and curiouser

Email to Baader me thinks. I guess you've no idea how old it is?