User feedback

Read what ONAG’s users have to say:

Dennis di Cicco, Sky & Telescope field test, December 2012 issue

“As clever as the concept behind the ONAG® is, the devil is on the details, and that’s where the ONAG® really shines.
The device,… , is extremely well engineered and, more importantly, well made.”

“After working with the ONAG® for many nights last fall, I can certainly say it’s easier to use than any off-axis systems I’ve tried (and that includes the few that I built myself). It also produced some of the most currently guided image sequence I’ve ever obtained.”

Read the full field test review here.

John Hayes, Bend, Oregon, USA

I have been using Innovations Foresight ONAG XT for about six months and I am extremely impressed with it. The design is well thought out and overall, it is very easy to use. I normally shoot with a Canon 6D on a Celestron C14 Edge using a Starlight Xpress Lodestar X2 guide camera. Although, it takes a little care to set the spacings correctly with Edge series telescopes, the system is easy to configure.   The advantage of on-axis guiding is that it is possible to select the brightest guide star over a very wide field of view and it is even possible to guide on stars within the target itself. It is simple to use sky-mapping software to identify the optimum guide star for any target. This is a significant advantage over off-axis systems that often struggle with off-axis aberration and a more limited annular field. The dichroic beamsplitter used in the IFI system is of very high optical quality, which means that image quality is unaffected by the guider.  I have found that guiding in the NIR works quite well, though it does require a camera with good sensitivity in the NIR but that’s not hard. Perhaps the only thing missing is the ability to remotely control the guider positioning system, which might require a large area guide sensor for remote operators. The guiding performance is as good as it gets. Recently I saw peak guide errors over 1.5 hours of about 1 arc-second with rms errors of about 0.34 arc-seconds. That’s pretty much seeing limited performance. Overall, the IFI system is superb and I highly recommend it.

John Hayes, Ph.D.

Bend, Oregon


Adjunct Research Professor

College of Optical Sciences

University of Arizona

Tucson, AZ

Greg Santos, San Diego, California, USA

I have been using the ONAG/SC for several months now with a 250mm/f5 Harmer-Wynne
Astrograph/8300 camera/Lodestar combination, and it has effectively replaced my old
Mitsuboshi off-axis guider.  I found the ONAG/SC very straightforward to understand,
install, and use (it is, after all, only a kind of specialized diagonal).  I had no trouble
finding guide stars, but the challenge with my particular OTA was the very large central
obstruction, close to 60 percent.  My guiding results with my A-P Mach1GTO were
adequate, but not quite what they could have been.  Dr. Baudat immediately came to
the rescue by offering to provide an astigmatism corrector for the guide port on the
ONAG/SC.  With this addition, my results have been better than ever, since the
ONAG/SC has eliminated any residual flexure (and pick-off mirror shadowing) that
previously existed in my imaging train when using the off-axis guider.  If your OTA
meets the backfocus requirement, I have no hesitation in recommending this well-
made, precision device for imaging use.  Once you try it, you will not want to go
back to any other guiding solution.

Don Waid, Denton, Texas USA

“The ONAG is a major improvement over any other guiding equipment I have utilized since I started astronomical imaging some 10 years ago. I currently use a domed observatory and a 12 inch RC OTA on an equatorial mount. My dome shutter opening is only 28 inches wide and often my external guide scope becomes masked by the edge of the opening resulting in the loss of a guide star. Since the ONAG guider is using the main OTA’s field of view, loss of the guide star because of the obscuring dome is not a concern. With the ONAG, flexure, inherent with external guide scopes, is no longer a problem to struggle with. Using an off axis guider or dual chip camera often makes locating a useable guide star difficult. With the ONAG this no longer poses a problem. Having the entire field of view of my OTA available to the ONAG makes finding a usable guide star much easier than when I had to rely on a thin donut around my field of view. Dr. Baudat’s, and his staff’s, pre and post-sales support are second to none. I cannot express enough gratitude for all the great, and timely, assistance they provided me.

An image benefiting from the excellent guiding provided by my ONAG may be viewed at the following link:”

Mario Motta, Gloucester, Massachusetts, USA

“I have had the pleasure to test out the larger version of the ONAG (XT) on my 32 inch F6 relay telescope (f = 4,800 mm) in Gloucester, MA.”
“I can say that with each new advance in guiding accuracy and ease, I have always been enthusiastic, but the ONAG clearly is the best method of guiding I have ever seen. Looking at the guide star on my monitor, it appears as if the Earth stopped turning.
“With Off Axis guiding, what I presently use, it works great if a bright enough guide star is found, but as we all know, that is not the case quite a number of times. I use a rotator, and AOL, and frequently if only a faint star is found off axis, then exposure time of guide star is increased, limiting the benefit of the AOL. Other times, the object of interest is not well centered on the frame to accommodate a suitable guide star. Other times the guide star is marginal, and faint cirrus or other glitch ruins an imaging run”.
“Enter the ONAG. On the very first try, I found it intuitively easy to use, and remarkably robust and accurate in guiding. Instead of off axis hunting for a guide star, the ONAG guides on the same star field you are imaging”
“No off axis or flexure issues to be concerned with. I am now able to use my AOL with great effect, guiding with 0.3 sec guide imaging in every case. The guide star looks locked, and my very first images were hubblescque. I tested at the zenith, and at 45 degrees and the results were fantastic, each sub frame was better than my previous processed images. I then did M83, only 14 degrees over the horizon. I have always had problems attempting objects that low as you have increased atmosphere, and increased twinkling of stars. To my great astonishment and delight, I got perfect tracking. I suspect the reason is the same effect that causes a red sunset. The longer rays of the sun penetrate the atmosphere, while shorter wavelengths scatter. Guiding by infrared uses even longer wavelengths, thus less apt to “twinkle” and thus gives you better guiding.”
“Finally, even if the ONAG was only as good as an off axis guider, it is still much better. Since the camera never needs to be rotated.. You can use the same flat all night. The guide stars are easily found, as you can scan the entire field of the object and surroundings for the brightest star available, making tracking nearly foolproof.”
“I feel this is the ultimate design in guide star tracking and imaging. I am a firm believer in the system and plan on solely using this type of tracking from now on. My only problem now is… I need to re-image the entire sky to upgrade my stock of sky images!”

Frank Colosimo, New Ringgold, Pennsylvania USA

“I am very happy with the ONAG® from Innovations Foresight. I received great help on the install from customer support.
The guiding is much better than I was able to get with a guidescope and I have a nice field from which to select guide stars.
Thanks for making a great new product!”

Scott Rosen, Pine Mountain Club, California USA

“The ONAG® has been the perfect replacement for my guidescope on my C-8 SCT with an F/6.3 focal reducer.
Having done off-axis guiding back in the films days, I can appreciate how easy it is to find guide stars with the ONAG®. Using the ONAG®, I have improved my images dramatically, as the stars and DSOs are much sharper than when I used a guidescope.
I had some initial troubles using the ONAG® (all of which were attributable to problems with my scope and mount). While trying to isolate and fix the issues, Gaston (CTO of Innovations Foresight) was tremendously helpful. It was quite a pleasure to work with him.”

Erik Monteith, Lakes Entrance, Victoria Australia

“The ONAG has been one of the best purchases for my observatory, and basically solved the
guiding issues on my RC10. It has made finding a guide star so incredibly easy. Imaging with an
OAG was frustrating at the best of times. No more wasted frames due to bad guiding.”

Joe Stat, Tucson, Arizona USA

“Great success last night!
I did a sequence of 10 sub-frames, each 5 minutes long.
All ten were near perfect in quality (nice round stars) and their registration was very near perfect.
I never, never, ever, had a good 5-minute exposure on an f/6.3 Celestron C11 before … ever.”

Ken Klein, Newhall, California USA

“Is it very good? NO. Is it good? NO. IT IS GREAT. It took about 2 minutes to align the ST402 guider with the ST10 imaging camera by sliding the guider camera out a bit. Then I took a 20 minute image and the stars were perfect.
I am sure there are a lot of people like me who have been hoping someone would create a good off axis or on axis guider for a SCT. Up until now all we have done is pay a lot of money for what turned out to be paperweights.”
C14 owner.

Brett Eden, Victoria, Australia

Would I recommend the ONAG? Absolutely. The benefits of near-infrared guiding are not simply theoretical, you can see them right there in your guide camera images and in the results that you take home at dawn. Compatible with the majority of systems out there, the reasons in favor of switching to ONAG far outweigh those against it. I’m glad to be rid of my guide scope!

Peter Nerbun, Perry Hall, Maryland USA

I use an 1848mm EFL F/6.3 SCT because I like to record fine detail within individual sections of nebula structure.  The problem is that even small guiding errors introduced to a large focal length SCT often result in stars that are misshapen.  This is especially true when using narrowband filters to record long 15 minute individual exposures that are required to capture faint nebula structure from my light polluted suburban location.  So in order to minimize guiding errors I needed to find a guide accessory that used the same telescope for both the guide camera and the main imaging camera thereby holding such errors to an absolute minimum. I tried an Off Axis Guider however finding a suitable guide star with an OAG in the midst of all my light pollution can be quite challenging especially when seeing is less than ideal.   My search for an answer to this dilemma led me to the ONAG.   The ONAG gives me access to many more guide stars that are less affected by sub-optimal seeing conditions than does the OAG; thus the ONAG has made possible the high quality imaging of tiny detail within individual sections of nebula structure by using a large focal length SCT from my suburban location.

Mark Shelton, Birmingham, England

I experienced my first real telescope when I was 17, a Criterion Dynamax 8, I’m now 54 & have always had a soft spot for the Catadioptric telescopes. However I was nearly consigned to the old belief that despite the best efforts Cats rarely produce consistent sharp images suffering from bloated stars & poor focus drift.

I tested a number of guiding solutions recently on my Celestron Edge HD ranging from a Celestron off axis guider & an 80mm refractor guide scope with a lodestar x2 guide camera on the back. The results were never satisfactorily with these solutions. Through the off axis guider the guide camera often could not find a guide star & if one was found it was usually too faint or too close to the edge of the field to be really useful. The guide scope never helped much either –all I obtained mostly were egg shaped images probably because of flexure. I like to guide at nearly 2 meter focal length to get a good image scale & resolve fine detail & with either of these solutions this was not possible without much gnashing of teeth as image after image was returned flawed. 280mm aperture at F7 needs long exposures and these solutions failed in this respect to produce acceptable images.

I needed something better- far better & this came in the guise of the innovations foresight ONAG. I’m using a Paramount MX+ mount with the Celestron OTA in Parallax rings so the foundation is solid. The ONAG is very solid & has absolutely no detectable flexure. The Lodestar X2 guide camera is screwed on the back with a C-mount adapter so no movement there & the imaging camera, an Atik 460EX, is again screwed to the top of the imaging port with T-rings.

The Celestron Optical assembly suffers from very rapid expansion & contraction when subjected to temperature differences & I’ve seen changes in focus in less than a minute. If this is not monitored constantly the result is bloated stars, washed out images with a subsequent loss of fine detail. How do I know this- well I use another solution which works hand in hand with the ONAG & that is the fast focus SMFS from Optec. This mounts the secondary mirror on a drive shaft with an accuracy of movement of 200nm- an incredibly small step. Software, Focus Lock (again from Optec but derived from the original Sharp Lock developed by Gaston), working with the SMFS, measures the centroid on every guide frame and from its initial calibration is able to refocus the telescope on the fly. This means that the primary mirror on the Edge HD can be locked eliminating another source of flexure as focus is controlled by moving the secondary mirror. This is not some cobbled together “Heath Robinson solution” but a highly integrated well thought out package-they work together like hand & glove by design.

The proof of the pudding is in the eating. I have never produced such good results since I’ve installed the ONAG & Sharp lock software solution. The images being returned, seeing conditions accepted, are as sharp as the optics allow and the star images stay round even after 15 minutes at 1960 mm focal length. The only guide errors I see are from atmospheric conditions. Since the guide camera is guiding in the near infra-red the stars are much less affected by twinkling and the guiding is far more accurate. I use PHD2 which despite being simple does all that is required.

In closing I could not be happier with this solution- the earlier guiding equipment is now being sold off so I can buy the XM version of the ONAG which will be able to use my Atik 11000 camera. I will never user another guiding solution as this is exactly what I needed- I wish I had bought it years ago and saved myself much pain & frustration.

The help & support from Gaston is over & above what can be expected from a vendor & I firmly believe that you will be buying into the best guiding solution available.

David Lindemann, Valais, Switzerland

What a wonderful piece of engineering! I use ONAG XT with SharpLock on my setup : 10micron GM2000HPS-II mount, Takahashi FSQ106ED, Apogee Alta U8300 monochrome and 7 positions filter wheel. With ONAG XT + SharpLock my focus stay perfectly focused without interruption of the capture process from dusk till dawn. (More than 30 panels) in a minimum of time by maximizing the number of image captured during the few clear nights as much as possible. To plan and automate the capture process of ultra-wide field mosaics from tile to tile, I developed my own software. Since, I use SharpLock in threesome with MaxImDL® and SkySurveyor and I was able to capture more than 108 panel’s mosaic on Orion ( in less than two months. Thanks to ONAG® XT with SharpLock®, nights after nights the FWHM of captured images stay optimal. Now, I have the ultimate toolbox to capture ultra-wide field mosaics in a minimum of time and a maximum of image quality without having to stay up the whole night and the ONAG XT and SharpLock are a keystone of this process.

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