Meade LDX 75 with an Imagingsource DMK 41

[NASA GSFC Intern]

Hello everyone,

I've posted an introduction thread in the welcome forum, so I'm going off my conversation from there.

I feel like there is a pretty simple answer to all of this, so here it goes... We are using a Meade LXD 75 and want to use an Imagingsource DMK 41 with it. From what I understand, the current setup we are using has the focus pushed back too far away from the camera to allow the DMK's CCD to see anything. I'm pretty new to all of this high end stuff, so any help I could get would be greatly appreciated!

Yes, I used the search function. Maybe I just don't know the right terms yet?

Thank you everyone for your time,

-Anthony

[hemihaggis]

hi anthony , which variant of the ldx are you using ? is it the sn8 or sn10 or the refractor or schmidt cassigrain or newt ?? ,, each one of these different designs will have a different requirment as to how far the chip or camera is located to achive focus , i think a schmit cass will need an extension tube to focus ,whereas a newt will not need an extension ..im sure a more knowledgeable member will pop along soon .. cheers

[StevieDvd]

I have recently purchased the DMK21 and bought the short nose piece to sort out the ccd focusing.

See here there are both shorter and longer adaptors.

The short one solved my issues with some other cameras too.

[NASA GSFC Intern]

First, thank you everyone for the quick replies!

hemihaggis,

I'll have to get back to you on the answers to your questions. I don't have unlimited access to the telescope right now, so the next chance I get, I'll get all the answers. I'm not sure I'm familiar with all the terminology your using. Does sn8 refer to the diameter of the lens? We are using an 8 inch telescope, if that helps sort out anything. I do apologize, I'm picking up where other interns left off from the summer, so I don't have all the information I'd like to have.

StevieDvd,

If I'm looking over the site you linked to correctly, the 15mm / 32mm barrel refer to the part directly attached to the DMK. From what I understand, this isn't the part that needs to be shortened. I'm going to attach an image of the part I believe needs to be shorter. It's the one on the left of the images.

Unfortunately, I have not witnessed the out-of-focus images first hand, my information is all word of mouth, so I don't know how they had everything configured when observing out of focus images. They may have been using the full length of the barrel when testing, and not sliding that part in to reduce the distance. You can see what I'm referring to in the attached images. I'm also unsure if I'll need a shorter barrel as well as a shorter ... whatever that is called on the left. Neck?

Thank you everyone. You have been helpful already. I'll work on getting more specific information regarding the Telescope as soon as I can.

-Anthony

[StevieDvd]

From the pictures it does look as if the adapter actually attached to the camera could be shorter. In you pictures it also has a fliter added making the nose piece even longer.

It can be made a little shorter by removing the adapter (exhibit a) from the camera first, then the adapter plate still on the camera (exhibit can be removed and put aside. The first adapter (exhibit a) can then be screwed directly to the camera.

This reduces the spacing a little. If you then insert the camera into your 2" to 1.25" adapter see if it fits snugly without any space. If not try without the filter. If it still protrudes that would indicate a shorter nose piece may be required.

Hope that makes sense and helps.

Steve

[NASA GSFC Intern]

A ha, I believe I see what your talking about. How does this look? I'll try and get to the telescope tomorrow and see if this fixes the focusing problem. Any money saved is a win for us!

Do you know if a shorter 2 inch to 1.25 inch adapter exists? It looks like that's the next thing that will need to be shortened.

[StevieDvd]

That looks a lot better. See how that works now. Can't respond on the 2" adapter, it looks OK to me but someone else with more knowledge may suggest otherwise.

[NASA GSFC Intern]

hi anthony , which variant of the ldx are you using ? is it the sn8 or sn10 or the refractor or schmidt cassigrain or newt ?? ,, each one of these different designs will have a different requirment as to how far the chip or camera is located to achive focus , i think a schmit cass will need an extension tube to focus ,whereas a newt will not need an extension ..im sure a more knowledgeable member will pop along soon .. cheers

hemihaggis,

I have been informed that we are using the Newtonian LXD75 N-6AT.

I'm going to try and get to the telescope today and test the slightly shorter setup.

[hemihaggis]

yep im pretty sure shorter should work better , the 6 inch scope is a newtonian design ,and in theory they should need as short a tube as possible to focus, indeed some newtonians cannot focus a camera and need a low profile focuser . i dont think this is the case with the ldx though . trial and error !

[NASA GSFC Intern]

Thank you so much. I'm going to try and get access tomorrow (Thursday), and see if I can focus on anything.

I do have another question, regarding the CCD. It appears that some specks have found their way onto the sensor. Is there any way that I can clean the sensor?

[hemihaggis]

ooohhhh , cleaning sensors ...oooohhhh tis tricky by all acounts ... lots of stuff on google about how to......

[NASA GSFC Intern]

It looks like I'm in luck with the specs on the camera. It's on the glass in front of the CCD, not the CCD itself, thanks goodness! I'm going to try some of the methods listed here Cleaning The CCD Chip Of DMK/DFK/DBK Astronomy Cameras / Astrophotography / Astronomy Cameras Blog

[NASA GSFC Intern]

After finally getting back on the roof, success! My only concern is that the focus was almost all the way pushed in, and I'm not sure how much further the focus may or may not need to be adjusted for celestial objects. We have some cleaning to do, but I don't think it's on the CCD, I think it's on the IR filter. It's clearly dirty when looking at it.

Check out them trees!