My experiences with testing back focus distances have consistently shown that I get better star shapes with less back focus distance than is recommended. My C8 at f/10 looks best (and plate solves to the expected 2032 focal length) at 80mm, not 105. With the 0.63 reducer I use just the ...
There is one other way to get the widest possible field of view still using 1.25" eyepieces: a focal reducer. This is a lens that threads onto the back of the scope and shortens the focal length of the scope around 37%. With this new lower magnification, the same maximum field of vie...
First, a normal angiographic study does not exclude a disorder of coronary vascular function. In a symptomatic patient with INOCA, coronary angiography may be considered incomplete without adjunctive diagnostic tests of coronary vascular dysfunction (Central Illustration, Table 1) (9,23,24). Other ...
and using a focal reducer and a 40mm eyepiece to give a 7mm exit pupil with a 5mm shadow. This made sure the shadow was bigger than my daylight-adapted eye pupil, which was 3mm or less. When I put my pupil right in the center of the shadow and just the ...
fb is the Barlow's focal length (a negative value). Here is the original reference to the use of the above formula (with an example using the 2.7x APM Coma Correcting barlow): https://www.cloudyni...post&p=13331277 You can also solve for L (when knowing the other variables): ...
If the Celestron reducer requires a 105 mm back focus to obtain the best image, then you need to set the focal plane of the camera 105 mm back from the flange on the Celestron reducer. If you have already been doing imaging using a DSLR and the reducer, then use the same back focu...
MallinCam 1.25" focal reducer MallinCam 2x barlow (2") Televue 2x, 3x, and 5x barlows (1.25") Location Rural Iowa, right on the border between Bortle 4 and 4.5 skies. I set up in my driveway (where I sit by the scope(s) ) or below my patio and control the scope/camera from...
No doubt a good C14 does better in many situations than a freaky sharp 10" but that's really off topic. In comparison a statement like: "People just have very different experiences, expectations and opinions on what a "freakishly sharp" telescope is. One person's "freakishly sharp" SCT ...
And is there a way to quantify this? Or is my guiding good enough and I should spend time improving other areas? I am using a C11 EdgeHD with a 0.7 focal reducer. My camera is an ASI128MC Pro. Thanks for any information you can point me to. ...
I also use my scope for planetary astrophotography, so I have a pretty good record of how much it varies… although I don’t even try anymore unless it’s a top 5-10% “seeing evening” now. If seeing is not top notch, out goes my planetary camera and in goes my reducer and my ...