Mobile phone camera down the eyepiece.

[SkyPhil]

Hello

I would love to know how people do this. I have tried several phone cameras and all I can see is a bright glow in the middle and the eyepiece around the outside.

That's if I can hold the camera steady enough in the first place.

I have also tried one of those camera holder adapter things, that was a bust. 

Cheers

Phil

[Zermelo]

It can be difficult to get the position right, and some eyepieces are more "fussy" than others. I have failed miserably, even using one of the (cheaper) phone holders.

Others have reported favourably on this version, which is more expensive but gives you fine control in three axes.

[Stu]

I have managed some decent images both hand holding the phone up to the eyepiece but also using mounts. My preferred one these days is the one Paul linked above.

Getting the distance to the eyepiece right is very important so that you see the whole field of view. The first two images below show the effect of being either to close or too far away, the last one shows a correctly positioned camera. I have deliberately over exposed these so you can see the field stop of the eyepiece in the last image.

Controlling exposure is very important too. Often if the target doesn’t occupy much of the field of view, the phone will over expose the image so you need to correct that. It depends which phone you use by either the standard app or a more advanced one will allow this. I use ProCam 8 on iPhone myself which allows control of ISO, shutter speed and focus.

Good results are certainly possible with practise and patience. The last three were taken using a small (but high quality) 76mm refractor with the phone mounted on the eyepiece.

 

[Neil H]

Hi if you have the Samsung galaxy when in camera mode swipe to the right and it comes up with pro settings also go in to camera settings and you can turn on voice control so to take a pic just say shoot

[Richard_]

Those are some fantastic images from @Stu!

I don't have a lot of experience shooting through the eyepiece, but here's my results. I place my diagonal upwards so I can look down and let gravity help hold things still! 

Getting focus can be a pain. If you have a 'pro' mode on your phone, see if you can set focus to infinity. Then see if you can adjust exposure. Having a Bluetooth shutter or voice activated can help prevent moving the phone about once you have focus etc. 

Here's a couple of images of the moon and Saturn as taken through my 120mm refractor. There are some reflections from my optics. I can't remember what eyepieces I used, my picture shows the 20mm WO swan. Saturn  was captured with either the WO or 15mm TV plossl and a x2 Barlow (https://www.firstlightoptics.com/barlow-eyepieces/bst-starguider-2x-short-barlow-lens.html). No fancy phone holder for me! 

[Elp]

Most phone cameras revert to a slow "shutter" speed in low light especially if it has a (dumb) auto setting with no manual controls so point light sources will overexpose, it's next to impossible taking an astro photo with any detail like this.

Your eyepiece will also make a large difference on whether the camera can focus in the first place, the distance you need to move the camera away from the eyepiece, visible FOV etc. This is the most difficult aspect if trying it freehand, if your phone is going to spend a second or two taking this image you won't be able to as your slightest hand movement, even balance within your legs or torso will move from the alignment point (where your camera can see the object through the eyepiece). With the moon it isn't so much of a problem as its so large, anything else this becomes extremely problematic. It's even more problematic at long focal lengths, magnifications and if you haven't got tracking on your mount. I've never used a bracket, always done it freehand.

One thing to do, never ever touch the scope or anything attached to it. If your camera has manual exposure control use this over the auto mode and reduce the shutter speed. If your camera has a burst mode where it takes multiple images per second use it. Failing that, video mode is effectively a 24/25/30/60/120 FPS burst mode (depending on your camera hardware and software), the issue only being exposures are short, but this is what you want with solar system objects. You can then choose any good frames afterward via post processing, Google's default photo app allows you to scroll through video when editing and you can edit out what you don't need. Use a PC video editing program and you can narrow it down easily to individual frames.

Edited October 11, 2023 by Elp

[Ratlet]

I use powershot app to manually control the camera and prevent it doing dumb things like the autofocus chasing the seeing.  I also use the moveshootmove phone holder.  It is the bee's knees.

To line everything up I shine a light down the telescope, makes it a bit easier.  Think about the focal length of the eyepiece as well.  Long focal length means the phone will need to be far away.

Works really well on the moon, okay on planets and not tried for DSO yet.

[Sunshine]

Getting handheld phone images up to eyepiece can be very tricky amd requires patience and the right combination of eyepiece and camera settings. My eyepieces are fairly wide angle and have a large lens up top which makes it easier to align the phone camera but one must remember that the sensor on the phone camera is tiny and alignment of image coming from eyepiece with a tiny sensor can be a pain. If shooting handheld without a phone adapter, i form a ring with my index finger and thumb then rest this ring on the eyepiece then rest the phone camera centered over the ring. This helps stabilize the phone above the eyepiece   While I use my other three fingers as support against the side of the eyepiece so I can slowly raise and lower the camera above the eyepiece to get image centered, zooming in a bit also helps to fill the FOV on the camera screen instead of it appearing as though the image is at the bottom of a cylinder. Once image scale is achieved i then gently tap the image on the phone screen to achieve focus and exposure, one focus is set, one must quickly and repeatedly tap the shutter, its lucky imaging really, you may shoot twenty images and get one decent one. Below is an example of what I can do handheld with practice and patience through much trial and error but I now can repeat these results fairly consistently. If one zooms in one can see it is not as sharp as it seems, it is about as good as I can do handheld which I think is quite good considering the difficulties involved.

Edited October 11, 2023 by Sunshine

[RT65CB-SWL]

Imaging lunar or solar* with a smartphone/tablet is not easy. I find you need a minimum of three or four hands...

• one: to hold the smartphone/tablet over the e/p.
• two: to press the shutter button.
• three: for focusing the OTA.
• four: keeping the OTA on track of your target if a manual mount is used.

Below is a lunar and solar handheld image taken with my iPhone 12 before.

I have now bought a Celestron NexYZ via SGL’er @jadcx

Link here to the NexYZ... https://www.firstlightoptics.com/adapters/celestron-nexyz-3-axis-universal-smartphone-adapter.html

 

* remember to use safety solar film/filter that covers the front of your ‘scope or a solar wedge when solar imaging!

Edited October 11, 2023 by RT65CB-SWL

[Beulah]

59 minutes ago, Sunshine said:

Getting handheld phone images up to eyepiece can be very tricky amd requires patience and the right combination of eyepiece and camera settings. My eyepieces are fairly wide angle and have a large lens up top which makes it easier to align the phone camera but one must remember that the sensor on the phone camera is tiny and alignment of image coming from eyepiece with a tiny sensor can be a pain. If shooting handheld without a phone adapter, i form a ring with my index finger and thumb then rest this ring on the eyepiece then rest the phone camera centered over the ring. This helps stabilize the phone above the eyepiece   While I use my other three fingers as support against the side of the eyepiece so I can slowly raise and lower the camera above the eyepiece to get image centered, zooming in a bit also helps to fill the FOV on the camera screen instead of it appearing as though the image is at the bottom of a cylinder. Once image scale is achieved i then gently tap the image on the phone screen to achieve focus and exposure, one focus is set, one must quickly and repeatedly tap the shutter, its lucky imaging really, you may shoot twenty images and get one decent one. Below is an example of what I can do handheld with practice and patience through much trial and error but I now can repeat these results fairly consistently. If one zooms in one can see it is not as sharp as it seems, it is about as good as I can do handheld which I think is quite good considering the difficulties involved.

That's a superb image.

[Stu]

2 hours ago, Ratlet said:

Long focal length means the phone will need to be far away

That’s generally true, but it is actually the eye relief spec which shows you where the camera needs to be. With a 5mm Ortho it will be about 4mm away, and a 32mm Plossl about 25mm. However something like a 5mm Pentax XW or Vixen SLV has 20mm eye relief so you need to be much further away than a 5mm Ortho.

[SkyPhil]

Thanks everyone, a mixed bag of results there, I was also wondering if there was an eyepiece camera? That could sit over the rubbery bit of your eyepiece?

Not looking for James Webb telescope quality, just a nice way of recording observations.

Cheers

Phil

[John]

I think the main challenge is that the exit pupil (which is what we are trying to image) is often very small (eg: 1-3mm) so the optics of the mobile phone camera have to be positioned and maintained extremely precisely in terms of both centering and distance from the focal plane to get a decent image. And then there is exposure etc, etc to get right.

I have managed a few decent images of the Sun, moon and Venus with a mobile at the eyepiece sometimes using a low cost mounting adapter and sometimes not. Lots that did not work out very well though 🙄

 

Edited October 11, 2023 by John

[Astronomist]

31 minutes ago, SkyPhil said:

I was also wondering if there was an eyepiece camera?

Some eyepieces have a thread concealed under the eyecup for this purpose. Almost any astro camera ( ZWO, QHY, ect ), as well as a DSLR, can be used in this way with appropriate adapters.

[Elp]

If you're going to go down that route get a flip mirror diagonal instead. Visual eyepiece on top, flip the mirror to camera straight through, no taking bits and pieces off the scope constantly. I've had one or two eyepieces with threads on them, never used them.

[Ratlet]

1 hour ago, Stu said:

That’s generally true, but it is actually the eye relief spec which shows you where the camera needs to be. With a 5mm Ortho it will be about 4mm away, and a 32mm Plossl about 25mm. However something like a 5mm Pentax XW or Vixen SLV has 20mm eye relief so you need to be much further away than a 5mm Ortho.

Gah, my mistake.  I meant to say eye relief!  Just finished night shift yesterday and digging a ditch today and my brain is hanging out my bum 🤣