Dim picture

Willy

New to this...just purchased an as1662 to work with my Celestron C11 cat ..why is my image on the screen so dim and small (even when zoomed)... it's definitely not what I'm seeing through the tube (without eyepiece) it is also blurry, how can I get this thing dialed in looking at a terrestrial object ..is there a tutorial that explains this... should I be using eyepiece projection or no eyepiece??

johnpd

You meant the ASI662 camera? We need a lot more information as to your setup.

What object were you looking at?
Are you using any type of focal reducer? If you are using the full focal length of 2800mm, the image will be dimmer depending on your exposure setting.
What exposure setting were you using?
How did you mount the camera, through a diagonal or straight through?
What adapters are you using between the focuser and the camera if any?
Which ASIStudio app were you using?
To get proper focus, set it up in daytime and focus on a distant object if you have one available. Or you can try the Moon which is now available as it approaches the full phase next week.

JohnD

Willy

I was just trying to get it sighted in on a terrestrial object during the day, I'm also getting the black spot from the secondary mirror in the middle of picture, I tried diagonal and straight through... can't find any "exposure settings"....I can find very little instruction on this

johnpd

What are the adapters you are using between the camera and the focuser? You will need a total backfocus (distance between the camera chip and the C-11 focuser) of 55mm. The camera chip is 12.5mm from its top so you need an additional 42.5mm of adapters to make up the difference. That distance can change if using a focal reducer depending what one you are using.
Which ASIStudio app were you using? ASILive is probably the best in this case. There is a rough (older) guide to ASIStudio here (https://astronomy-imaging-camera.com/tutorials/a-user-guide-to-asistudio-software-and-the-zwo-asi183mc-camera/).
I have attached a picture of ASILive using my ASI662 camera. I was using the fisheye lens on it so you see basically my ceiling.
-- a. At the top under "Camera (via USB3.0) you see the ZWO ASI662MC as connected. Next to that is the turn on/off button for the camera.
-- b. Under that is the resolution setting (1920*1080) which is the full resolution for the camera.
-- c. To the right of that is the "Gain" setting, You have Low(0), Medium(252), High(450), or custom. The more gain you use the more you amplify the image, but also you amplify noise.
-- d. Below Resolution is the "Exposure" setting. There are a preset number of exposures as well as a custom option. What you use depends on the amount of lighting you are in.
-- e. To the right of Exposure is "Bin". Don't bother with that now. Leave as "1".
-- f. Below that is the "Cooler" setting. Since the ASI662 does not have a cooler, ignore that.

You will get an image when you turn the camera on. All you need to do is adjust the exposure until you get a properly lit image. Then adjust the focus until you get it correct. You need to use a distant object so that the focus you end up with is as close to what you will have with deep sky objects as possible.

JohnD

Willy

Thanks John, you've given me plenty to work with for now... I'll get back to you if necessary

Willy

Ok, my picture looks similar to yours when panning camera around the room but when I put it in the telescope I only get a tunnel with a bright glare ... I've tried different settings, when I zoom it to around 160% the tunnel disappears but the glare remains...no picture, only glare

johnpd

Willy

Please answer question #1 that I posted above. We need to know how your image train is set up and whether it is set up properly. If it is not, you will never get proper focus.
What exposures were you using? You most likely have two problems: over exposure and out of focus. Again set up outside in the daytime pointing at a distant object and then work with it. Do not zoom in. Reduce the exposure until its brightness is diminished. Then work with the focus.

JohnD

Willy

johnpd I dont know what else to tell you, it is directly hooked to rear of scope, no diagonal
no eyepiece..did you get pictures I sent a couple days ago?? I believe the focal length of the C11 is 2800..I used the zero gain setting, anything more over exposed...I never went higher than the third increment on the exposure settings or it also over exposed (went white or splotches of color)..I tried inserting a Barlow but that didn't help, do I need a focal reducer??...(online tutorials say "no") I don't even get a good image on camera WITHOUT the scope

Willy

It is set up as shown in picture... camera directly hooked to scope, I removed the fisheye lens which was 90% of the problem, unfortunately I have no distant object to focus on because of tree cover ( I'm trying to shoot through window to neighbor's chimney but I can't seem to get it focused).. I'll probably have to move the scope out at night and use the moon....is there a focus adjustment in the program or is it all done with the scope?..the image through the camera is nothing like what the scope is looking at, should be a bright grass and tree landscape but it only shows a blurry black and white moving image on screen, if I adjust gain or exposure up it shows blotchy colors but no image or goes completely white

johnpd

Willy

No wonder you had a problem if you were using the fisheye lens. That is not supposed to be used with a telescope. Also DO NOT use a Barlow at this point. That makes it worse.

As I mentioned above, there needs to be a backfocus distance of 55mm from the end of the telescope focuser to the camera sensor chip. otherwise you will not attain proper focus. The camera chip is 12.5mm from its top so you need an additional 42.5mm of adapters to make up the difference. Unfortunately ZWO does not include any additional adapters with the ASI662MC. You need the following:

M48 Male to M42 Female Adapter: https://agenaastro.com/zwo-m48-to-m42-adapter.html
M48 to M42 16.5mm Extension: https://agenaastro.com/zwo-m48x0-75-female-to-t-t2-m42x0-75-male-adapter-set-with-37-5mm-extension.html
5mm M42 Extension: https://www.amazon.com/dp/B0BDV5652K?psc=1&ref=ppx_yo2ov_dt_b_product_details
[This is a set of adapters. You may need some of the larger ones if you want to use a Barlow]

Set up as follows starting what is plugged in the focuser:

The 1.25" to M42 eyepiece adapter that came with your camera.
Newer 5mm M42 Extension.
ZWO M42-M42 21mm Extension.
ZWO M42-M48 Adapter screwed into the male end of the 21mm extension.
ZWO M48-M42 16.5mm Extension.
The ASI662 camera.

This should get you the 55mm backfocus.

JohnD

Willy

Thanks... that's exactly what I needed

johnpd

Revisions to my last post:

In item #2 for purchase, that is a two adapter set which includes the M48 to M42 16.5mm extension plus the M42-M42 21mm extension.

In Item#2 for Setup, these are Neewer adapters not Newer.

JohnD

Willy

I will also be setting up my 60mm Coronado (refractor) solar scope .. will I need any adapters for that?

johnpd

Well I might rescind everything I said. I ran a test indoors with my C-6 and the ASI662MC camera. Although it is not a C-11, I would think the functioning would be about the same. I was about 30 ft from an object to focus on. I used a 25mm eyepiece in a diagonal to center the object. I then replaced the eyepiece with the camera using the 1.25" nosepiece. The room which contained the object was not brightly lit so I adjusted the exposure to accommodate for that and began to adjust focus. I did not have to adjust the focus very far before I could achieve focus with the camera.

I have an 80mm refractor that I use for solar. It has an external Lunt H-a filter and a blocking filter diagonal. I use a different camera, but it has the same internal backfocus (12.5mm). I plug it right into the blocking filter using the 1.25" nosepiece and need no adapters.

So I don't know what to tell you. Try using a diagonal, focus with a low power eyepiece, then replace it with the camera. Adjust the exposure down until it is somewhat dark. The fixed exposure settings in ASILive are a nuisance. It is a pain to get the proper exposure if it lies between two very different settings. At that point you can adjust the gain to brighten the image. That also has fixed values so if that does not help, you either have to adjust both exposure and gain or set up new values. The other possibility is to try SharpCap. That has sliders for exposure adjustments.

JohnD

By the way, you will not be able to get a full solar disk with your Coronado and that camera. Check this site:

https://astronomy.tools/calculators/field_of_view/

You would need a focal reducer.

Willy

Success! the problem was the window I was trying to shoot through.. didn't realize it would cause that much blur, don't think I need the focal reducer..I'll have to wait for a high moon to test further (I'm surrounded by trees) I'm assuming I'll be able to crank the gain and exposure up a little higher outside in the dark...the tool with the link you provided is pretty cool, what is the "width" of this camera?....looks like I get pretty close to a full disc on the Coronado even without a reducer...thanks for that

johnpd

Good to hear. Now you can get to work on getting some images. Here is the info from Astronomy Tools on your Coronado 60 and the ASI662MC. I used the Moon instead of the Sun as they are essentially the same size in the sky. As you can see, your combo does not quite make getting a full solar disk. You would either need a reducer or take a mosiac (2 images) and combine them).

JohnD

johnpd

Your other option would be a different camera.

JohnD

Willy

Thanks....will I need IR/UV Cut Filter?

johnpd

Yes if you will be doing night astrophotography with your C-11. What you need is the cut filter plus an adapter that will allow you to screw the filter right into the camera. You screw the filter into the adapter then the adapter into the camera. You can then screw the 1.25" nosepiece into the camera as the adapter goes deep into the camera.

Example of how it goes into camera: https://astronomy-imaging-camera.com/product/t2-1-25-filter-adapter/

Adapter: https://agenaastro.com/zwo-t2-1-25-filter-adapter-t2-1-25-3.html

Filter: https://agenaastro.com/zwo-1-25-inch-ir-cut-filter.html
NOTE: The filter label says it is IR only but it is both as the website states below.

JohnD

johnpd

A better camera for solar might be the ASI664MC if you want to color although a monochrome camera would be better as you would get more detail. The ASI664MC gives you a larger FOV so the Sun would easily fit in. It also gives you better sampling.

JohnD