More advice sought - ITF

[Starflyer]

I have a Solarmax II 60 in which the ITF was rusted, see my old thread here.

I went ahead and ordered a replacement 656 ITF Bandpass Filter from Maier Photonics, fitted it and tested it.  Visually it was great, bright, sharp with good surface and prom detail, I couldn't get anything like a decent image on my camera.  I left it and due to a house move and some other stuff it didn't get used again.  It's been on my mind as I keep seeing images of some nice activity again so I pulled it out today.

Visually it's really good, but again I just couldn't get a decent image, it's hard to describe so I took some video.

This was me trying to focus, I have the position marked so I know I was close, but I tried the full travel.  The disk  seems to move, distort and change brightness as I move the focuser.

 

This is me increasing the exposure from minimum to slightly higher, again it distorts the shape.  At no point when focussing and changing exposure could I get a disk to show.

 

As a last resort, to prove I wasn't losing my mind I swapped in the old rusted ITF, focus position was the same, exposure had to be increased a fair bit to compensate for the rust.  Not too bad an image and it proved that the scope is working as it should, visually it was as I remembered, duller and no sign of proms.

 

I had the blue side facing outwards from the screw ring to start with, as that what I read was the correct orientation, I tried flipping it over, and it made no difference to the view / image.

So what can I try next?  Is it possible the replacement ITF was faulty on delivery, is something else wrong?

 

Thanks,

Ian

[Peter Drew]

Unfortunately my laptop can't download your videos so difficult to make a valid comment.  However, if the visual image is good and detailed you should be able to photograph it, failure to do so points towards something to do with the imaging train or the exposures.  The new brighter visual image would need a lot faster setting, not difficult to overexpose a solar image.      🙂

[Ibbo!]

I managed to open them in virtual dub and the first 2 are way over exposed.

Use the histogram function in Flycapture or Sharpcap.

[Starflyer]

Thanks for the replies.

I tried minimum exposure, minimum gain in sharpcap when I was experimenting yesterday and couldn't get anywhere, the camera is a PG Chameleon btw.  Do you think that the image could be bright enough to cause this even at min exposure and gain?

I don't think I have a ND filter here, I do have a Baader solar continuum filter I could try on the camera, that should darken the image enough if it is just too bright.

 

Thanks again,

Ian