focusing d3200 and t-ring adapter

[kristafi]

Iam having major problems trying to use my d3200 and 10" zhumell telescope together. I bought the t-ring adapter and ring for my camera. When I remove my lens and attach my adapter to my d3200 it will not focus. I dont know if its a setting or what. I know I have to do the focusing manually but no mater what I turn to focus its just blurr. I dont know if im supose to put an eyepeice in the t-ring then screw it to the camera or what. But even with the t-ring off its just blurr. I've tried making a video with no sucess. Ive read about using a barlow lens but I have no idea without a diagram how to assemble it. Please help.

[lensman57]

Iam having major problems trying to use my d3200 and 10" zhumell telescope together. I bought the t-ring adapter and ring for my camera. When I remove my lens and attach my adapter to my d3200 it will not focus. I dont know if its a setting or what. I know I have to do the focusing manually but no mater what I turn to focus its just blurr. I dont know if im supose to put an eyepeice in the t-ring then screw it to the camera or what. But even with the t-ring off its just blurr. I've tried making a video with no sucess. Ive read about using a barlow lens but I have no idea without a diagram how to assemble it. Please help.

Hi,

I am not familiar with your telescope but you attach the T adapter to your Nikon as you would attach a normal lens and then you screw this on the telescope focuser all the way in using the T thread, you may have to unscrew something off the scope focuser before you get access to telescope male T thread. If you are doing all this and not achieving focus then the problem is not the camera and the T adapter but the scope, if the focuser has not been designed to accomodate DSLR imaging it will not give you enough inward travel to achieve focus, as the focus plane of a DSlR is set quite a bit away compared to an eyepiece or a webcam and the focuser has to have quite a bit of inward travel to get focus with a DSLR. If it has been designed with imaging in mind then you need to go over your steps one by one till you sort out the problem. Hope that this helps and good luck.

A.G

[knobby]

You might have luck if you put a Barlow on the scope... I had to with my D300 on a Skywatcher 10" dob.

Don't give up ...

Good luck

The Barlow just fits in the telescope focuser then the camera fits in the Barlow

[kristafi]

Thank you guys so much. I played around with my camera yesterday with the adapter on and an old lens. I did realize that its not my camera . I got the camera to focus when I held up a lens for it to focus through. From what I understand the lens is your telescope when you use it that way. So tonight I will try to get my telescope recalibrated and try using a barlow. I have a barlow from a different telescope but it may be too long. If someone could tell me the barlow they use for their nikon I would appreciate it. I just dont want to buy the wrong one. Thanks again for your help I am one step closer to having my dream set up!

[Russe]

Your camera might focus on smth nearby, but will it for stars?

Stick your camera into the scope during daylight, point it at smth at the horizon and see if it focuses. If your chip is very sensitive (mono) you may need to adjust ISO/gain/brightness/exposure time so that you see smth on the screen.

What sort of scope is it? A Newtonian reflector? Schmidt Cassegrain? Maksutov? Refractor?

[Russe]

What I've done is move the primary mirror closer to the focuser - now I've got visual and photo focus.

[knobby]

Or to connect to a Barlow with the SLR use a barlow like this

http://www.harrisontelescopes.co.uk/acatalog/Celestron_Universal_T_Adaptor_Barlow_1.25_.html

Or skywatcher do one too.

[JamesF]

A common cause if this is happening is that the focal plane of the primary is too far inside the drawtube for the focuser to be able to get the camera sensor to coincide with it (which is how it needs to be for the image to be in focus). Using a barlow (some of them have a T-thread around the top which makes it easier) can be a workaround because the barlow has the effect of moving the focal plane outwards and the camera can then reach it. Obviously that does reduce your field of view. Replacing the focuser with a low profile model can sometimes help if you get enough of a change in focuser length, but it's an expensive option. And as Russe has said, moving the mirror perhaps an inch up the OTA can move the focal plane outwards far enough for the camera to be able to reach it. Some people do that by cutting down the tube, but a less "invasive" method is to replace the collimation bolts with longer ones.

James

[kristafi]

Okay again thanks for all your help! Im getting closer. I ordered the t-ring with barlow and was able to focus during the day on a house far away and it worked. I tried it tonight and wasnt able to focus on stars, im thinking its too dark even at my highest iso settings. My question now is can you use a telescope lens somehow? It just seems like to get interesting photos like jupiter you would need to use a lens in the telescope. I could see how the big bright moon might work but I have to use at least a 9 mm lens to see jupiter even without the camera. If anyone knows if I can attach my telescope lens to the t-ring please let me know how. Im happy im one step closer but this is frustrating. Thank god for this forum because there is not much info on how to do this on the web, and I would never have got this far without all your help so thank you all so much.

[JamesF]

What exposure length were you using when you were trying to focus on stars? I'd suggest you start at ten seconds, perhaps even longer.

James

[MyRomeo]

Or to connect to a Barlow with the SLR use a barlow like this

http://www.harrisont...rlow_1.25_.html

Or skywatcher do one too.

I use that barlow with my Nikon D3100 and Astromaster 5" scope and can focus no problem on the stars. Without the barlow I just get blur!

As JamesF says, the focal point is basically not far enough out to reach the camera sensor. With the barlow fitted this focal point is moved further away from the scope and thus the camera can achieve focus. As also said, you can also reposition the primary mirror but that seems a bit extreme when a simple barlow will allow focus (unless the drop in F ratio is a problem to you!)

[Russe]

Moving the primary is not a massively big deal. If I can do it, anyone can!!

[wxsatuser]

Okay again thanks for all your help! Im getting closer. I ordered the t-ring with barlow and was able to focus during the day on a house far away and it worked. I tried it tonight and wasnt able to focus on stars, im thinking its too dark even at my highest iso settings. My question now is can you use a telescope lens somehow? It just seems like to get interesting photos like jupiter you would need to use a lens in the telescope. I could see how the big bright moon might work but I have to use at least a 9 mm lens to see jupiter even without the camera. If anyone knows if I can attach my telescope lens to the t-ring please let me know how. Im happy im one step closer but this is frustrating. Thank god for this forum because there is not much info on how to do this on the web, and I would never have got this far without all your help so thank you all so much.

You could try afocal.

Attach the camera to a projection eyepiece.

A dlsr can be attached directly to something like the Revelation 40mm eyepiece or I believe you

can attach a dlsr to a Baader Hyperion Zoom, with the extra adapter.

[P_Monty]

Okay again thanks for all your help! Im getting closer. I ordered the t-ring with barlow and was able to focus during the day on a house far away and it worked. I tried it tonight and wasnt able to focus on stars, im thinking its too dark even at my highest iso settings. My question now is can you use a telescope lens somehow? It just seems like to get interesting photos like jupiter you would need to use a lens in the telescope. I could see how the big bright moon might work but I have to use at least a 9 mm lens to see jupiter even without the camera. If anyone knows if I can attach my telescope lens to the t-ring please let me know how. Im happy im one step closer but this is frustrating. Thank god for this forum because there is not much info on how to do this on the web, and I would never have got this far without all your help so thank you all so much.

My camera adaptor comes with a piece like this:

http://www.scopesnskies.com/prod/60.html

It takes an eyepiece internally.