GoPro Hero3 Black on Questar
Posted 08 January 2013 - 06:16 PM
Posted 08 January 2013 - 06:23 PM
Another feature of the GoPro Hero 3, is there is an iOS App for it. Using the App allows complete control of the camera function via Bluetooth; including real time viewing of the projected image on either an iPhone or iPad.
Posted 09 January 2013 - 05:41 PM
Posted 11 January 2013 - 08:06 PM
Posted 11 January 2013 - 08:09 PM
Acetone - carefully.
Posted 11 January 2013 - 10:19 PM
Time lapse of .5, 1, 2, 5, 10, 30, 60 sec intervals. All in a tiny camera that weighs just 2.6 oz with battery.
I have the GOPRO HERO2 but never considered it for imaging through a scope as it would seem you need a little on board zoom to fill the frame and those crazy wide angle settings would be terrible. Interesting that you got it to work for u . The HD res is breathtaking ill say that.
Posted 14 January 2013 - 05:29 PM
Posted 16 September 2014 - 09:12 AM
I would like to revive this thread in an attempt to better understand the coupler necessary to hook up a GoPro Hero3+ to a Questar 3.5.
As all of you know, the GoPro video camera is unsurpassed as an ultra small for underwater and POV settings. It is very Questar-ish in its design and functionality.
Barry started this thread with terrific shots of a $50 bill using a 3/4" PVC coupling that he machined to be used afocally with a 24 mm eyepiece.
Does anyone know of a coupler for diagonal or axial viewing with the GoPro? (Perhaps I should be asking GoPro about that).
Others have suggested that the GoPro lens could be removed and the camera coupled directly to the Q.
Since the Go Pro has WiFi, it may be possible that interesting astronomical viewing could be accomplished to one's IPad or computer. I assume vignetting is a problem and that focus may be an issue. As Barry noted, the GoPro does not yet have a zoom function.
Posted 16 September 2014 - 06:36 PM
The Questar Camera coupling set and the Questar P-thread to T-ring adapter (or C mount) has most of what you need for either prime focus or afocal adapters. You want everything to screw together.
If you don't have access to a machine shop to cut 42mm P or T threads, I found a technique that works well and is easy. I purchase inexpensive camera T-ring adapters (<$10 on Amazon). It doesn't matter what camera because you will only be using the 42mm T-thread as a nut. The camera bayonet adapter is easily removed on the ones I bought. I also bought a 42mm drill bit (<$10 on ebay with shipping from China). I drill a 42mm hole in a piece of aluminum or plexiglass that I use as a mounting plate for the camera. I slip that hole over one of the Questar extension tubes from the coupling set and then screw the T-tread nut to hold it firmly in place against the collar on the Questar extension tube.
I've used this for two setups. An afocal mounting for my Sony RX100 point and shoot. Images of the assembly and some sample astrophotos are in this Flickr set:
A prime focus mount for a Raspberry Pi camera module that I control wirelessly from an iPad. Details here:
Here is an example image:
Posted 16 September 2014 - 09:57 PM
Thanks for this terrific explanation and your sensational photographs. I will undoubtedly have more questions, but you have me launched expertly.
Posted 17 September 2014 - 08:19 AM
Good work! It's great to see info on hooking up cameras designed in this century to the Questar.
An afocal adapter needs to put the camera lens within the eye relief of the eyepiece in order to get the full FOV. This means that you need an eyepiece with long eye relief (which your 24 mm EP should have) and that the adapter needs to hold the camera very close to the EP. You can hand hold your GoPro to find the sweet spot, but I suspect that you will get a much better FOV if you remove most of the length out of your adapter. Usually this ends up being as close as possible because the lens is usually recessed a bit for protection.
If you can remove the GoPro lens and use the camera at prime focus that will improve the image quality but you will loose some magnification, but you can get that back with Barlow lenses. Questar offers some that screw in in-line to it's adapters.
I found that the hardest part of a useable camera setup is aiming and focusing. In addition to the normal camera view, the following two features seem essential for astrophotography:
* a magnified focus live view with edge highlighting so that you can get focus spot on.
* a high sensitivity preview mode so that you can see guide stars in the camera live view well enough to aim and frame the shot (possibly not needed with the Q if you can get the camera par focal with the EP in the other port).
Does the GoPro offer any features that help with these the problems of low light focusing and aiming?
Posted 17 September 2014 - 09:32 AM
As you probably know, the GoPro Hero 3+, of course was made with video as its primary use. ( I use it mainly for underwater applications, and while I hope that the next iterations will have a zoom feature, the underwater footage I have shot, as a stark amateur, in Hawaii and the Galapagos are surprisingly spectacular (thanks more to the subject matter than to the photographer). There is no reason that the camera shouldn't be useable with a Questar 3.5.
The GoPro software applications allow for lots of cropping and zooming given the 12 mp sensitivity. The software would be easy for experienced astrophotographers such as you.
It seems that still photography was almost an easy design afterthought for the GP designers...to wit, no electronic zoom features on the camera itself. The lens is fixed as well, at f/2.8 and one can vary the shooting at 5, 7 and 12 mp. The key to a GPs use with the Questar is it's somewhat limited advertised minimum focus at 18 cm. Users have shown on line closer shots are possible with some loss of definition. Barry's $ 50 Grant photos bely some of the GP's limitations.
Also, perhaps of some astronomical use is the GP's burst feature of up to 10 photos per second, and other rates, which might be employed while adjusting slightly the manual focus on the Q to pick and choose which shots get finer focus. Finally, being able to control the GP by a built in wifi feature is, it seems, essential in assuring absolutely no motion in activation of the shutter, changing modes, etc. While your machined extenders with proper fittings are much, much more elegant, If Barry's simple PVC pipe extension to an EP can be workable then it is a simple matter of experimentation with the GP and Q using proper polar alignment and tracking.
As you alluded simply holding the GP up to the eyepiece for a shot, or a series of bursts, may be the most inelegant solution, requiring perhaps some sort of clamp between the GP and the Q. One of the GP 's strong suits is a bewildering variety of clamps for every application from motorcycle handlebars, to helmets, to snorkel masks, etc., etc. .....the GP is very lightweight, with some of the clamps almost as heavy as the camera. Finally, lest I sound like a GP sales brochure, the camera can be used as did Barry to send by wifi photos to an iPad or computer or by use of the LCD attachment...for instant gratification.
I will be interested in your response to this.
Posted 17 September 2014 - 11:21 AM
I don't understand how the minimum focus distance is relevant. For afocal photography the focus point of the camera lens will typically be infinity - focusing on the virtual image and not the end of the eyepiece.
The PVC pipe extension is brilliant, I just suspect that Barry would capture much more of the image with a shorter length. His afocal solution will also work with any telescope.
Good polar alignment and the Questar's clock drive will allow images up to about 20" of exposure, periodic error in the gear train is the limitation. The Qs setting circles are good enough to get an object in the eyepiece FOV most of the time, but not good enough to frame it well especially with small imagers that may capture only a small part of that FOV.
IR remote triggers or shutter delays work fine to control vibration.
I use a live view over WiFi to aim, focus, and control the Raspberry Pi based system (which produced the Jupiter image above). The primary issue with WiFi in my setup was the latency of images over the wireless link that made focusing difficult. I was able to take some good images with the Raspberry Pi, but it was clear to me that to continue using it I would need to write software to give me convenient access to the features needed to make focusing and framing easy. The RPi setup includes a complete Linux computer system so the software is just a small matter of programming :-) I'm sure that software can be written for the GoPro as well, but it would be a real find if their included software has these features (most DSLRs and even some high end point and shoots have them).
I asked about the specific focusing aid features, because IMHO they are important for astrophotography, but unlikely to be important in a typical GoPro use case. If they are there out of the box, it might well be worthwhile getting a GoPro - otherwise I'll stick to the RPi or something similar because it is easier to extend the features in a standard software environment like Linux.
I do afocal photography both with the Sony RX100 and an iPhone. I like it for quick takeaways at star parties or taking photos on Newtonians without enough back focus for other techniques. I find that the quality of afocal images suffers from all of the additional optical surfaces in the eyepiece and camera lens so I prefer other techniques where I have a choice. Even with an iPhone I can usually get most or all of the field of view except with wide field eyepieces.
One of the outstanding features of the Questar is the optical switch box which allows you to have both an eyepiece and a camera reliably mounted at the same time, so I made mounting suggestions that take advantage of the Questar and it's standard accessories and minimize the need for tools. The T-ring "nut" to Questar extension tube collar connection gives a high stability mounting for non-traditional cameras using only a hand drill.
For example: If the lens of the GoPro is removed, the same technique could be used to mount the GoPro to the axial port eyepiece adapter, that Barry uses, with a t-ring to 1.25" eyepiece tube adapter (an inexpensive standard part). But then there may be standard c-mount or t-ring solutions for the GoPro.
I hope that was the right amount of detail to understand my POV. One of the great things about astronomy is that there are so many different and interesting ways to see and capture amazing things. One of my frustrations with the Questar is that although it can greatly benefit from the latest in imaging, very little is written down and a newbie like me has to do a lot of sometimes painful experimentation to get to workable solutions. It's great to see people trying new things with the Q!