Good morning from the sunny Eifel.
Yesterday I tried the Rosette Nebula again and this time I set the native format . I exposed 25x120sec and... after stacking with DSS only stars, no Rosette Nebula (or only very weak after stretching with Fitswork). In the Fits preview only stars were visible. This morning I compared JPEG as native and RAW. With JPEGnative you can see the longer exposure in the preview by the clearly brighter picture. With RAW as native, the preview becomes more and more dull...
I'm a little sad and helpless because the conditions were optimal yesterday.
Matthias

what i want to say with this: if you set RAW as native format of the canon, all long time exposures seem to be corrected downwards and therefore underexposed... This doesn't happen with JPG. No exposure correction or am I doing something wrong... i thought with fits as transfer the native format doesn't matter...
Matthias

Can you post a link to one of the captured RAW frames?

Hi, Jasem,
Yes, shure, hope it works...

www.magentacloud.de/share/tnp9zjpd3q

I don't think you can register reasonable Ha signal with unmodified Canon with 120s exposure.

... but i took 25 120sec pics... so after 1h stacked, some signal must be seen... perhaps something with debayer
Matthias

ok, as already described here from Radek, the camera modified without Astro is not optimal, so I removed the IR filter in the meantime let's see if this brings better results.
Matthias

Matthias, which telescope do you use? Please note that removing the IR filter will, obviously, let pass all IR. Refractors are not corrected for IR radiation meaning that that radiation will not come into focus. This will produce big halos around bright stars and blur fine details. It is possible to image with a camera without a built in IR filter but you will need a fringe killer or L filter to cut out IR radiation.


HTH, Wouter

Hello Wouter,
yes i know and i have... I'm using a Skywatcher ED 80, old version. Togehter with teh canon it provides the wright frame...
... but did somebody have a look to my sample FITS files? I#m interested what' wrong with them or me
Greets Matthias and i think the last clear night today here in the northern Eifel.

Sure, I have taken a look. There's no Ha signal in them at all.

Hello Radek et al.
this time a little bit H-Alpha unfortunately the onstep telescope control has left after I wanted to do the darks in between, but of course the tracking was over... so there are only about 25 60sec /800ISO pictures... but the camera astro modification was successful...
Now the weather is getting worse for the first time since 2 weeks... Here is a raw picture after DSS and fitswork stretching as jpeg... maybe one can still get something out in PS.
Good night first
Matthias