How to "zoom" with DSLR?

[msacco]

Hi guys, just got my DSLR adapter for my telescope recently(This is what I bought: https://www.aliexpress.com/item/32864926848.html?spm=a2g0s.9042311.0.0.27424c4d4YUNvP )

So I tried taking a picture of Jupiter with it, and I'm just not really sure about how I should do that, I've watched some videos, but I don't really understand how it works, I managed to see jupiter, but it was so small on the camera so I really didn't manage to get anything, I also tried using 2x barlow but it really didn't help much.

From what I understand you don't use eyepieces usually with a DSLR, but then what should I do to "zoom" in on the object?

Also, I'm not using any PC programs with it, just connecting the DSLR to the telescope and using the camera itself to take a picture.

Sorry for the really dumb question, but if someone would be able to answer that it would be really great.

Thanks!!

[Stu]

I believe that adaptor can also work via the eyepiece projection method, you put a 1.25" eyepiece in the tube and that magnifies the image.

http://www.astronomysource.com/2011/10/13/eyepiece-projection/

[msacco]

18 minutes ago, Stu said:

I believe that adaptor can also work via the eyepiece projection method, you put a 1.25" eyepiece in the tube and that magnifies the image.

http://www.astronomysource.com/2011/10/13/eyepiece-projection/

With the adapter I have do I have the option to do so?

Also, I've seen in a lot of threads that eyepiece projection is not as recommended, why is that?

[Gfamily]

When used at prime focus, you can use a rule of thumb that the image scale is equivalent to an eyepiece with a focal length = to the sensor diagonal. 

A DSLR with an APS-C sensor has a diagonal of 26mm, so the image may be small and will need cropping.

[ollypenrice]

31 minutes ago, msacco said:

With the adapter I have do I have the option to do so?

Also, I've seen in a lot of threads that eyepiece projection is not as recommended, why is that?

Firstly I suggest you put your kit in your signature so that people know what scope and camera you are using and can tailor their advice accordingly.

Deep sky imaging and planetary imaging are diametrically opposed activities requiring different equipment, methods and processing. The correct way to discuss the extent to which a setup is 'zoomed in' is to talk about image scale, or how much sky (measured in arcseconds) lands on each pixel of the camera. The fewer arcseconds per pixel the more 'zoomed in' you are. Just two values control the image scale in arcseconds per pixel. These are pixel size and focal length. Pixels sizes only vary by a relatively small amount (from around 3 microns to around 9.) Your DSLR probably lies in the middle and, anyway, it's what you have so it isn't a variable at this stage. This leaves focal length and it is this which must be extended if you wish to reach a good image scale in which Jupiter's image will land on a higher number of pixels and so make a bigger image. (Cropping has no efffect on this. You cannot enlarge an image by cropping it, which is why the term 'crop factor' should never be used in astronomy. Cropped or uncropped, the planet's image remains the same size when viewed at 100% on the PC.) So...

1) What is the focal length of your telescope? (I don't know, but it isn't enough!)

2) How can you extend it? The usual ways are to use higher mulitiplication Barlows (4x) or expensive Powermates or eyepiece projection. I'm not a planetary imager so am not up on the merits and demerits of the alternatives but if your adapter allows it the EP projection will be the least expensive. It is not recommended for deep sky imaging for various reasons but essentially you don't need it. There are lots of deep sky targets for every focal length in existence.

So I suggest you put your kit in your sig and buy yourself a really good primer on astrophotography:  https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html You'll never spend a better twenty quid.

Olly

[Stu]

1 hour ago, msacco said:

With the adapter I have do I have the option to do so?

Also, I've seen in a lot of threads that eyepiece projection is not as recommended, why is that?

Yes, it looks like it does. If you hold it with the end that goes into the telescope facing down, you can drop (gently!) an eyepiece into the tube and it will lock into place with the locking screw. Only the slimmer eyepieces like plossls or orthos will fit, but give it a try.

[michael8554]

No matter what camera you use, the disc of Jupiter will always be X arcsecs in diameter - that dimension is determined by the focal length of the scope. 

So on a full frame DSLR, X will be a dot in the 25 Mp frame. 

On a 2Mp video camera, X will appear to fill the frame. 

But cropping the full frame DSLR to 2Mp will look the same. 

The best technique for planets is to shoot video and use stacking software to reject the fuzzy out of focus frames and only stack the few clear frames. 

You can do that with a DSLR in Crop Movie mode, or better, use a dedicated high frame rate planetary camera. 

To get a reasonable size image a Focal Length of at least 2000mm is required. 

Michael