Baader ASTF Astrosolar Filter OD 5.0 for imaging with Celestron 9.25 in WL?

[shadowchaser]

Hi everyone!!
I currently have a Sky Watcher Maksutov 180 with a Baader Astrosolar OD3.8 filter and it gives me very good results for WL photography. I wanted to try the same thing with a Celestron Edge 9.25 to have more resolution, but the OD3.8 filters in the Edge 9.25 size have not been in stock for a long time (In fact, there is no stock of any size on the Baader website).
Can I have good results with an OD5.0 on a telescope like the Edge 9.25 considering that it is an f10 vs the f15 of my Maksutov? Or is it really not worth it and I have to keep waiting for the OD3.8 filters to be back in stock?

Thank you very much!!

[marktownley]

The 3.8 would be the preferred option, but a lack of stock may well mean you have to use the 5.

[christian viladrich]

A few years ago, Baader stopped making Astrosolar ND 3.8 in size larger than A4. I am afraid they are not planning any new batch, unless a huge number of solar observers ask for it ;-)

I would try the A4 size on the C 9.25. Only a small part of the aperture would be limited to about 200 mm. So, you will still have some gain compared to the Mak 180 (provided the C 9.25 is well collimated ...).

The ND5 filter is unfortunately too dark for imaging. The Mak 180 would do better.

[shadowchaser]

A few years ago, Baader stopped making Astrosolar ND 3.8 in size larger than A4. I am afraid they are not planning any new batch, unless a huge number of solar observers ask for it ;-)

I would try the A4 size on the C 9.25. Only a small part of the aperture would be limited to about 200 mm. So, you will still have some gain compared to the Mak 180 (provided the C 9.25 is well collimated ...).

The ND5 filter is unfortunately too dark for imaging. The Mak 180 would do better.

Thank you very much Christian for your prompt response!
It's a shame they don't make it anymore, it works really well for its price. Without that filter I have no other options to achieve more resolution in my WL photos, a refractor larger than my Mak with a Herschel prism is extremely expensive.

[Montana]

It is s real pity they don't make it anymore. How big a batch would they need to make to get them to make it. Surely we could all club together? there is solar max coming and no one can image? ND3.8 is absolutely necessary for imaging.

Alexandra

[DavidP]

Agreed. I just wrote Baader asking them to produce the larger size. Maybe if enough of us wrote…

[Montana]

We all need to write an expression of interest here on the forum and see how many we get!

Alexandra

[DavidP]

Well I’d buy some

[DavidP]

I wrote Badder in regards to the larger ND3.8, and here is their reply:

“ Dear Mr. Pitre,

this film size will certainly not be available for a long time, please do not expect it in the next few months.

The reason is that we have to produce this film together with the regular 0.5 film because the production quantities of the special optical film and the effort are enormous. However, it will take a long time before a new general production is necessary and we regret that the 3.8 will not be available in this size for so long. As soon as we have carried out the next production run, we will make the film available again on the website. The best thing to do is to register there with the "Notify me..." function. you won't be able to get the information faster when we are available again.

We regret that we cannot give you any better information with a more precise time frame at the moment.
Best regards,
Service Team MR
BAADER PLANETARIUM GMBH”

[MapleRidge]

Hi All...

I had the same reply form Baader in early January when I checked the plans to produce more of the ND3.8 mylar. I do have the full aperture ND5 for my C14, but it requires longer exposures than my typical seeing allows. Once the new observatory is up and running I can put the C14 back on a mount and try again in the spring with better seeing (hopefully).

I'm hoping that there is enough interest for our group to nudge them to making a batch

Brian