My Questar Restomod
Gregory Gross

My Questar Restomod

My first Questar
My first Questar, one that was built in 1962, not long after I bought it in 2019.

In early 2019, as I describe in more detail in this account, I took the leap and became a Questar telescope owner. After getting my hands on a 1962 Standard model that was in great cosmetic condition, I fell in love with the experience of using a Questar even in spite of the significant optical and mechanical deterioration that my particular example had. In the end, my investment proved to be a good one.

After I acquired another example from 1962, one in excellent all-original condition, I became intrigued about the possibilities for the first Questar I had come to own. At some stage in the mid-1960s, a prior owner had already converted it to a wide-field model. As a result, it was no longer in original condition. Why not stay true to the approach that Questar’s founder Lawrence Braymer himself followed by adding improvements to scopes sent in for service? In the instruction booklets from the 1960s, the company wrote, “We constantly try to make internal improvements, and whenever possible we design the changes so that they can be applied to earlier instruments.” Why not continue in this same spirit?

An added source of encouragement came when I read a November 2019 New York Times article that described how some vintage automobile aficionados take collector cars and perform “restomods” on them—that is, they introduce modern features into classic vehicles to make them more usable according to today’s standards while retaining much of their original look. Why not follow this same approach with my first Questar?

My first Questar was indeed a good candidate for a “restomod.” Having a Questar with all of the beautiful cosmetic features of an early example but with the performance of a modern one was proving to be too tempting of a thing to pass up.

Corrector lens coatings failure
The corrector lens on my first Questar was showing clear signs of coatings failure.

In particular, I was keen to enjoy an up-to-date optics set. The reflective aluminum coatings on the original primary mirror had just started to corrode from the outside edge, and the optical coatings on the inside surface of the corrector lens were clearly failing.

But instead of fixing these problems simply by recoating the original optics set, I wanted the scope to benefit from the Questar’s current optical design. What I really wanted, in other words, was a new optics set.

The design of Questar’s optics had come a long way since production began in 1954. To get around patent constraints, Lawrence Braymer originally located the secondary mirror spot on the outside or “R1” surface of the corrector lens. (The “R” stands for “radius,” a reference to the figuring of the lens surface.) The design allowed Braymer to get around the patent constraints and move forward with production, but it also represented a less efficient system that forced light to travel through glass more times than what was really necessary. The result was a greater degree of light loss than what would have happened if the secondary spot was on the inside surface of the corrector lens. The problem was compounded by the fact that early corrector lenses had no antireflection coatings on their front surface, leading to even more light loss.

After that patent constraint expired, as Questar manager Jim Perkins wrote to me, optician Edward Kaprelian spearheaded a redesign that was evaluated on Princeton University supercomputers. In 1978, the company began production on units that featured a secondary spot on its far more logical position: the inside or “R2” corrector lens surface. (For more on the history of this design change, see this discussion in my Questar history.)

Over subsequent years, Questar refined their optics further. Several computerized tests have shown the current system to be essentially perfect. To my knowledge, Questar guarantees a minimum of 1/8th-wave PV (peak-to-valley) performance in all instruments they now produce.

How incredible would it be to have all of these improvements added into my own 1962 Questar, one that was built only eight years after production began?

After a few years of owning and enjoying the scope even in its optically deteriorated condition, I finally sent it off to New Hope for servicing and optics replacement. I’m grateful that a company that was founded in 1950 and began making its signature telescope four years later is still around to take in even early Questars for service. That parts and optical components produced today can be added to telescopes that were built generations ago is nothing short of amazing.

The Work

The scope that came back to me in the spring of 2022 was a stunningly beautiful example of an early 1960s Questar that had most of the classic looks of its era but that now had an up-to-date optics set.

Updated Questar
Updated Questar

When I sent in my Questar for servicing, I tailored my work request around the idea of making a telescope that was almost sixty years old as close to new as possible while still honoring its history and maintaining its classic appearance. As I mentioned above, the scope had already been converted to a wide-field model, so much of its internal mechanics had already been updated. What was left to do was to clean it up, fix its drive mechanics, and, most importantly, update its optics.

Questar replaced my scope’s entire optical train. Staying true to my Questar’s original configuration while also seeking the most longevity, I opted for a new Pyrex primary mirror and corrector lens with standard and durable magnesium fluoride coatings. The scope also received a new internal Barlow lens, a new diagonal prism, and a new finder lens and mirror. To top it off, I added two new eyepieces, a 16mm and a 24mm Questar Brandon, both of which come standard with new scopes. Between its entry point at the front of the scope and its exit point out of the eyepiece, light now passes through nothing but new and fresh optics.

I knew that one side effect of updating the optics to a modern R2 set was that a new corrector lens cell had to be installed and that it was going to be longer than the original. Because of the movement of the secondary spot from the outside to the inside surface of the corrector lens, the corrector lens itself had to move forward a distance about equal to the thickness of the lens in order to maintain the position of the secondary spot relative to the primary mirror. The new cell measures 0.420 inches, or about a quarter-inch longer than the original 0.218-inch cell. Questars with newer R2 optics can often be identified by examining the length of the corrector lens cell.

R1 vs R2 corrector lens cell
Comparison of corrector lens cells—the R1 lens cell of my all-original 1962 Questar (left) is significantlly shorter than the newly-installed modern one on my updated scope (right). Also note the difference in moon map color. My updated Questar probably received a new one when a prior owner sent it in for a wide-field conversion in the mid-1960s. Indeed, each hand-made Questar has its own individual character.

I was worried that introducing this change would mean that the scope would no longer fit in its original English saddle leather case. After reconciling myself with what seemed to be the likelihood of having to replace the case, I was delighted to learn after I got the scope back that it still slipped into its original case without problems. It helped that the case’s top panel had always had a bit of a bow in it. That imperfection was something I had frowned upon before; now, I was thankful for it.

Updated Questar in case
Even with its newer and longer corrector lens cell, the scope still fits in its original case with a bit of room to spare thanks to a bit of a bow in the case’s top panel.

I also tried to slip my updated Questar into the case that came with my all-original 1962 example, a case which has a nice and straight top panel. The updated Questar with its longer corrector lens cell was now just a bit too tall to fit into that other case without scraping against and pushing up on the top panel.

For the scope’s drive system, Questar replaced the drive disks and pinions with fresh ones. They also changed out the original nylon bearings with modern Teflon ones. When I received my scope back, I could immediately tell the difference. Before the service, my Questar’s altitude/declination motion was very stiff, almost unusably so. Afterwards, the slip-clutch motion for both altitude/declination and azimuth/right ascension was perfect. There is also zero backlash upon operating both slow motion controls. They feel brand new.

Since the original motor was quite noisy, Questar also replaced it with a much quieter one that they had salvaged from an early 1980s example that had been serviced in the past.

The interior material of the scope’s dew shield, which has a slightly different shade of purple compared to that of my all-original Questar—I’m reasonably certain it was also replaced when the scope was converted to a wide-field model—was worn out and looked awful. I requested that it be reflocked.

And since its leg hole plugs are more or less irreplaceable—and since I never used them anyway for their intended function as hooks for hanging the scope off a car window—I also asked for a modern set of flat plugs to serve as a working substitute for the originals, which I now store safely away.

Altogether, my updated 1962 Questar has a little bit of everything from every era: its original “Questar” side arm logo badges and English saddle leather case, the wide-field construction that was added to the scope around the mid-1960s, a drive motor from the 1980s, and new R2 optics. It’s a truly unique Questar with a character all its own.

Performance

Of course, the heart of any telescope is its optics. As delighted as I am to have an updated early Questar that has so many of its original cosmetic details intact, I am all the more delighted to enjoy a scope that performs so well both visually and photographically.

Since I also have an all-original Questar with an R1 optics set that also dates from 1962, the same year my updated scope was originally built, I was interested to see how the performance of the two compared with each other.

I don’t have an optical bench or precision measurement tools, and I can’t put my Questar through a thorough battery of laboratory-style testing. But my scope sees a lot of action, and I can describe what it’s like to use it in a variety of ways.

The evaluation that follows is one that reflects my actual hands-on experience using the scope for several different applications under typical, real-world conditions.

Test #1: Nearby Utility Pole

For my first test, I chose a utility pole that is perhaps 200 to 300 feet away from my backyard as my target. My atmospheric seeing conditions were typical for late afternoon during the spring—that is, not bad but also not the best. The heat of summer had not yet arrived, and I was able to conduct a test that I believe has usefulness for showing what a Questar can do under typical conditions.

With my Canon M200 mirrorless camera attached to each Questar, I began by setting my camera to manual mode, set the ISO to 200, metered the light, scrutinized the camera’s onboard histogram for the best distribution, and set shutter speed appropriately. I then incremented both ISO and shutter speed by the equivalent of one stop. For each setting, I took three images and chose the one with the sharpest appearance. In this way, I identified the best balance between a sufficiently fast shutter speed to freeze atmospheric turbulence and an ISO setting that lacked excessive noise and graininess.

I took the following images with a shutter speed of 1/500 second at ISO 1600. I captured the first with my all-original Questar with R1 optics and the second using my scope with new R2 optics:

Utility pole R1 optics
Utility pole R2 optics

In the first image, note the vignetting, which is due to the narrow-field construction of the all-original Questar I used to take the picture. Even my Canon M200’s APS-C sensor and its 1.6x crop factor isn’t small enough to avoid that vignetting. The second image, which I made using my updated Questar with wide-field construction, has only a bit of vignetting at the corners.

The following images are 1400 x 1150 crops saved at 100% quality from the original 6000 x 4000 straight-out-of-the-camera JPEGs. Again, the all-original Questar with R1 optics is first followed by the Questar with new R2 optics:

Utility pole detail R1 optics
Utility pole detail R2 optics

To my eye, both Questars rendered the utility pole’s wood grain and other details with excellent detail. But the updated scope edged out the older one in terms of resolution, color richness, and contrast. The Questar with new R2 optics clearly outperformed the one with its original R1 optics.

Test #2: The Moon

Of course, I don’t spend much time observing or photographing utility poles. Far more interesting to me is the Moon, our faithful friend in orbit around the Earth.

On a late spring evening with the Moon at approximately 45% illumination, I had an evening with good seeing and transparency before both worsened somewhat an hour later. For this test, I took three sets of ten photographs with both my all-original and my updated Questar, refocusing in between each set of ten. I then picked out the best image from each scope.

With my Canon M200 connected to my all-original Questar with R1 optics, I took this photograph at 1/4-second shutter speed at ISO 100:

Moon R1 optics

With the same camera connected to my updated Questar, I shot this photograph also at 1/4-second shutter speed at ISO 100:

Moon R2 optics

And here is a side-by-side comparison of a cropped selection in the middle of each image—first, the Questar with original R1 optics and, second, the one with updated R2 optics:

Moon detail R1 optics
Moon detail R2 optics

Again, both scopes performed well. But the updated Questar rendered lunar features with better contrast and sharpness, and the image I produced with it lacked the haziness that the original R1 optics produced.

The difference between the two scopes is far more apparent at the eyepiece. Because the original R1 design called for the secondary spot to be placed on the outside surface of the corrector lens, there is ample opportunity for the Moon’s bright light to reflect off the unmirrored inside surface of the corrector lens. When observing the Moon visually, this reflection causes a significant amount of haze around the lunar disk and a substantial loss of contrast on the disk itself.

The Questar with its new R2 optics set, on the other hand, renders the Moon with a wonderful level of contrast and resolution. The Brandon eyepieces also do their part for a superior observing experience. The visual difference between the two scopes is quite obvious.

Test #3: The Orion Nebula

Although I don’t typically call upon a long-focus 3.5-inch telescope like the Questar to do heavy-duty observing and imaging of fainter deep space objects, I do like to use my Questar to photograph the brighter showcase objects in the sky. There is no more pleasing object to go for than M42, the Orion Nebula.

Full disclosure: I made the following two images on two separate nights, so the following to image samples are not completely comparable. But it does demonstrate how much brighter my Questar’s new optics set renders the Orion Nebula photographically.

On an early February evening with a temperature of around 30°, no breeze, clear conditions, and average seeing, I was out with what was to become my updated Questar before I sent it in—that is, while it still had its original R1 optics set with failing coatings—when I captured this image of M42. The nebula was 14° west of the meridian at an altitude of about 41°, or about 1° below its highest altitude at the meridian. My shutter speed of my Canon M200 was 30 seconds and my ISO was set to 12,800:

M42 R1 optics

On a beautifully mild late March evening in in the mid-50s with average seeing, I was out with my updated Questar after I received it back with its new R2 optics. I photographed M42 with the same camera when the nebula was 46° west of the meridian at an altitude of about 30°, or about 12° below this object’s highest altitude at the meridian. Again, my shutter speed was 30 seconds and my ISO was set to 12,800:

M42 R2 optics

Even in spite of M42’s far less favorable placement in the sky when I took the second image, my updated Questar rendered the nebula much brighter and with much better detail than what its original R1 optics was able to manage. I attribute this to the significant improvement in light throughput that the updated optics set offers.

Whenever I have attempted to image M42 with my all-original Questar, I have gotten results that were similar to those I obtained with my updated Questar before its optics were replaced.

Test #4: Backyard Terrestrial Photography

In addition to its astronomical applications, one of my favorite ways to use my Questar is as a daytime terrestrial observing instrument. My backyard is filled with interesting subjects to photograph.

For instance, the western fence lizards that populate my region make ideal subjects especially for a slow telescope that operates photographically at f/16. As they bask in the sunlight, these little guys sit perfectly still as they watch for bugs to feed on.

Out of the many photographs I’ve taken of these little lizards, this is one of my favorites, one I took with my updated Questar from a distance of around 20 feet. My shutter speed was 1/40 second and my ISO was 200:

Lizard R2 optics

This is a 100% crop of the same image—note the incredible resolution in the lizard’s eyelid and in the scales below its mouth:

Lizard detail R2 optics

You can only get this kind of image with first-rate optics, and those that Questar installed in my scope are just that.

A more unforgiving test for a telescope that operates photographically at a slow focal ratio of f/16 is action at the hummingbird feeder. But I feel like I’ve found the sweet spot in terms of a fast shutter speed to freeze the motion of the hummingbird’s wings and a reasonable ISO setting that doesn’t result in excessive graininess.

I took this image of a rufous hummingbird in good morning light from a distance of around 20 feet using a shutter speed of 1/1000 second at ISO 3200:

Hummingbird in flight R2 optics

A bit later, another hummingbird settled down on a tomato cage next to my feeder long enough for me to refocus, drop my shutter speed to 1/50 second and my ISO to 200, and take a single picture before it flew off:

Hummingbird seated R2 optics

This is a 100% crop of the same image:

Hummingbird seated detail R2 optics

Again, the resolving ability of my updated Questar’s new R2 optics set is simply incredible. The fact that these small birds are only around three inches long underscores how amazing that resolution is.

Since my all-original Questar with R1 optics has some problems with its focuser mechanics—it tends to bind up when I attempt to focus it on objects at close range—I don’t have any hummingbird images to share from that scope.

But I do have another comparison to offer. My first serious telescope was a 102mm Maksutov-Cassegrain that I bought from Orion Telescopes and Binoculars in 2014. As far as telescopes with mass-produced optics are concerned, it performs wonderfully especially for its price point. But for that extra bit of resolution and color contrast, you can’t beat a Questar.

Late one summer morning, I compared my 102mm Orion Mak with my updated 89mm Questar. First, the Orion Mak—1/1600-second exposure at ISO 3200:

Hummingbird in flight Orion Mak

And the updated Questar—1/1250-second exposure at ISO 5000:

Hummingbird in flight Questar R2 optics

And here is a side-by-side comparison of a cropped selection in the middle of each image—first, the Orion Mak and, second, the Questar with updated R2 optics:

Cropped hummingbird in flight Orion Mak
Cropped hummingbird in flight Questar R2 optics

In spite of its aperture advantage of 13mm, its faster focal ration of f/12.7, and its subsequent ability to allow the camera to operate at a faster shutter speed, the Orion Mak, albeit an admirable performer, routinely fails to deliver the level of clean resolution and rich color contrast that I can capture using my Questar. There is never really any contest between the two.

Conclusion

As I write this, I am smiling to myself as I contemplate my earlier progression from Questar skeptic to Questar enthusiast. As I wrote in my account of how I came to own and enjoy using a Questar, I was not at all convinced at first about making a large investment of hard-earned dollars into a small scope. My thinking now bears very little of the same sense of doubt that I had earlier.

To be sure, no telescope including the 3.5-inch Questar is the perfect telescope for every observing scenario. No telescope is. But for those applications in which a small, highly portable instrument excels, one would be hard pressed to find a better choice than a Questar.

And for those who might share my preference for all of the classic details of those early examples—the “Questar” side arm logo badge, the etched and enamel-filled dew shields that feature a deep purple hue, and so forth—and who might have access to an early example that may need a little love and care, I can think of no better way to have the best of both worlds than to send the scope in to Questar for service and for an optics set replacement like I did.

Updated Questar
My 1962 Questar “restomod.”

Can a Questar with first-rate optics outperform a larger mass-produced catadioptric telescope? In some ways, no, but in other ways, yes. For targets like Jupiter and Saturn, for instance, my updated 3.5-inch Questar renders a dimmer image at a given magnification and a smaller image through a given eyepiece compared to my Celestron C8 SCT, which I bought new in 2014. The smaller scope also can’t keep up with the larger one where deep space objects are concerned. My updated Questar does have an advantage in terms of delivering excellent resolution and contrast. Still, a given aperture will only do as much as the laws of physics allow it to do no matter how well an instrument’s optics are figured.

But comparing a smaller instrument with another that gathers over five times as much light isn’t a fair comparison to begin with, and doing so completely misses the point of owning and using a Questar. The fine mechanics, the ease of use, the versatility, the beauty, the optical excellence, and the overall first-rate execution of a telescope of its size all combine to offer the “Questar experience,” a unique thing that no other telescope offers. It’s just plain fun to use!

I can completely see how my 1962 Questar “restomod” will stay with me for years to come. It might possibly be the very last telescope I will ever own.