CanonEOS 6D 'stock-new 2017 model... from B+HPhoto' using a Baader 7nm HydrogenAlpha 2in. filter thru an APM Flattener thru a 152mm A+M Refractor(OfficinaStellare) and made into 16-BIT TIFFs in Canon Digital Photo Professional V4 . Four TIFFs were 890secISO6400 and one TIFF was 1321secISO6400 and then I Sigma-Clip stacked them in MaximDL Pro V6.16 and then I made some color adjustments with 'Levels' to reduce the 'green to 1.5' and the 'blue to 1.5' gammas to make the Rosette redder like the CanonEOS 6D's LCD screen preview at capture , and 'Color Adjust for Background as Magenta 2.0' for a magenta tone , some smoothing also done .x 1st image is a replica of the CanonEOS 6D stock LCD screen and shows full content at 22minISO6400 , 2nd image is the same way but is 15minISO6400 , and 3rd image is the same but is 7minISO6400 and this shows what you would see in the LCD screen after the image is taken …. the 3rd image couldn't be used in the '4th image' that had a Canon 6D Recipe applied in 'Canon Digital Photo Professional V4 for the RebelT7i' and there are four 15minISO6400 and one 22minISO6400 16-BIT TIFFs that I Sigma-Clip stacked in MaximDL Pro V6.16 … color adjustments were made because MaximDL showed them with a yellow-orange light tint and I used 'Levels green gamma to 1.5 and blue gamma to 1.5' to make the image redder and then 'Color Adjust for Background at 2.0 for Magenta' which gave it the color it is now … like the original TIFFs with the Recipe . Canon 6D recipe is for Neutral 5200K .x The CanonEOS 6D 'stock' DSLR allows 25% HydrogenAlpha at 656nm and does allow 658nm a little less and about 1% at 700nm … so it should be OK for up to 22minISO6400 on the bright Rosette and the minimum of 15minISO6400 ….The LCD Histogram and the Canon Digital Photo Professional 'thumbnail' images' Histogram using the Tool Palette 'Curves' shows the 'Red' for the 15minISO6400 Rosette just out of the left edge and the 22minISO6400 'Red' out of the edge a greater amount but the 'Blue' is clipped in both cases .x I was reading about a Polarizing filter like the Orion 2in. I have and it says on the Internet that it will reduce off-axis , off-angle light waves like scattered light from all different directions from getting to the sensor and clouding it up like air-glow and with the 'object' centered it will allow the straight-plane light waves in to the sensor from the 'object' with better color …. I'l try it on the M20 without any other filter and see if it stops stray light with the Polarizer at it's full open position , it with allow light thru with the TPO80A filter attached to it so that's another option . Baader has one also . x
