DSLR, poor focusing or haizeness to images.

[3Rotor]

hi everyone. I have a bit of an issue...

I tried my hand at the moon tonight, using the DSLR (1100D) hooked up the proper way with the T-ring and adapter, but for some od reason the images seem to have this hazeyness to them. I tried with all the different eyepieces I have, but with no joy.

Best I could muster from it was this.

if I remove the camera and just look into the eyepiece myself, the image is perfectly clear all the way right to the outer edge of the FOV. and the focus seem to be very crisp, which is what got me a bit stumped.

So then I tried something else, I removed the T-adapter from the 1100D and put it's original lens back, then I just manually held it to the Eyepiece, did some focusing and was able to get much improved imagery, all be it a wee bit on the shaky side, not to mention misalignment issues as well, non the less....

now, could this mean that I will be needing what seem to be called a field-flattener?

[Hugechris]

if I remove the camera and just look into the eyepiece myself, the image is perfectly clear all the way right to the outer edge of the FOV. and the focus seem to be very crisp, which is what got me a bit stumped.

(Cant see your photos fro some reason)

Correct me if I have missinterpreted what you are doing, did you focus the camera in live view after attaching the camera? The focal plane of the camera sensor will be at a different distance than your eye, so a difference in focus is to be expected with / without the camera if you are not refocusing between these adjustments.

[JamesF]

The haziness looks like the effects of dew to me, but I don't understand why the same would not appear in the second shot.

James

[3Rotor]

I definably do focus it , or at least try to, with the focuser on the scope, while it's attached through the T-adapter, even looking into the camera's view-finder, while trying to focus shows the image as having that haze to it,

What I'm thinking, or wondering, is that I'm basically swapping out my eye, behind the eyepiece, with a bare ccd. IE. no optics between the eyepiece and ccd of the camera, where as with ones eye, you still have one lens between the eye-piece and your retina, (or biological ccd).

this is what makes me wonder if I'm not missing something in the lineup between the scope and the camera.

[Hugechris]

I definably do focus it , or at least try to, with the focuser on the scope, while it's attached through the T-adapter, even looking into the camera's view-finder, while trying to focus shows the image as having that haze to it,

What I'm thinking, or wondering, is that I'm basically swapping out my eye, behind the eyepiece, with a bare ccd. IE. no optics between the eyepiece and ccd of the camera, where as with ones eye, you still have one lens between the eye-piece and your retina, (or biological ccd).

this is what makes me wonder if I'm not missing something in the lineup between the scope and the camera.

Edges of the field are always tricky, I have similar issues with the edges of some of my images, especially with poor seeing during warm nights, capturing a clean single shot is not easy. I have used at 32mm projection EP to image the full disk of the moon, the view through the EP has been lovely very sharp and great contrast. Then imaging through the same EP (with an extension tube - the drop off in focus at the edges is even more noticable with shorter EP focal length - from my Baader zoom EP), I get the edge effect (which is to be expected as the distance of the focal plane is some distance from the chip surface at the edge) as well as the expected loss of resolution from the reduced sampling frequency of the camera chip versus my eye.

The reduced spatial frequency of the pixels of camera compared to your retina will naturally degrade the image as well (but this is a small fraction of the effect you see here).

If you are concerned with the camera I would try bringing the brighter region to the centre of the image focusing using live view first at 1 x mag (on the camera) then refine at 5 x mag then if the image is in focus try 10 x. A field flattener will certainly help for the edges else building the image from a handful of mosaics to cover the disk a central focus might do the trick.

[3Rotor]

that does make sense, also, I guess we need to keep in mind, that with the eye, the retina is not flat , but curved, probably exactly for solving this blurry-edge syndrome.

[JamesF]

that does make sense, also, I guess we need to keep in mind, that with the eye, the retina is not flat , but curved, probably exactly for solving this blurry-edge syndrome.

In the case of the eye, it's always blurry around the edges. In fact the area that you see in focus at any given time is surprisingly small. You just don't notice because your brain does clever stuff whilst you're not looking.

James

[3Rotor]

aaa yes, so built in focus-stacking and all that, come part of the package, All we need is a way to "SAVE AS" what we think we see, to a Tiff...