Q. What is the Series IV and how does it work?
A. A modular system that can be switched between Ronchi-grating and knife-edge focusing, the Stiletto focuser temporarily attaches to a telescope in place of a camera body (either conventional film or CCD) and allows you to quickly achieve pinpoint focus using a star. Once the telescope is focused, you replace the Stiletto with your camera and aim at your target, whether it be stars and deep-sky objects, a planet, or the Moon. Click here to read all that Sky & Telescope magazine had to say.
To achieve perfect focus, this quick and simple 4-step swap-in, swap-out procedure is followed:
1 2 3 4 
Attach the Series IV Focus until bar-free Attach your camera Frame & Shoot
After reading the rest of this FAQ, you might want to read the Series IV Instruction Manual which has a lot of details and an exploded view of the Series IV.
Q. Which is better for me, a Series IV 'Stiletto' or the new CVF Series?
A. This is an easy question to answer. If you are new to astrophotography and do not know what direction your interests will take you, the CVF Series is hard to beat for flexibility. In addition to allowing you to focus precisely during daylight hours so that you can do general nature photography (including solar studies), it does an excellent job at focusing on the brighter night-time objects like the Moon and planets as well. For serious deep-sky photography of the Messier objects, however, the knife-edge focusing approach offered in the Series IV 'Stiletto' really cannot be beat since it takes your eye out of the focusing equation altogether and offers some nice convenience features. If you are still undecided, just give us a call anytime and we can figure out what you need together.
Q. Is this the best focusing solution for you?
A. There are lots of ways to properly focus a 35mm or CCD camera. Click here to read all about them. If you are just starting out and on a budget, you should try some of the more economical approaches first. But after trying all of them, I think you'll agree with others that the Series IV and CVF Series cannot be beat. They are simply the best values on the market today.
Q. Do you offer a guarantee?
A. Only that you'll go broke buying hypered film and spend days processing with PhotoShop. But sincerely, our products really work like a charm. If you happen to drop-kick one into a nearby swamp, however, I'll do my best to fix it and get the water out. I don't want any bad-mouthing out there from disgruntled customers, only praise from gruntled ones. We offer a 30-day Clear Sky Guarantee (no questions asked) and a 1-year warranty on our products.
A. My name is Richard Shell, and I teach business and computer courses at the University of Texas in the Lower Rio Grande Valley. The weather, climate , and food here are wonderful, but the night skies are generally depressing for amateur astronomers since clouds roll in continuously from the Gulf of Mexico. Astronomy and astrophotography have been hobbies of mine since I was 12 years old. This is a terrible place to take pictures of stars, but a great place to make focusers and talk to y'all. ( I just had to get that in somewhere to preserve the Texan stereotype.)
A. All of our products are capable of being upgraded to the newest 'Stiletto' Series. I always hate getting stuck with old technology, and I know you feel the same way too. The last thing I want is for one of our products to wind up unused in your astro accessory junk drawer. My own is full! So, an upgrade is always open to you for a really reasonable cost - all you need to do is email me and let me know what Series you have now.
Q. Is it worth it?
A. Well, if you're going to spend 60 minutes bent over in the cold guiding your scope, you will feel like a total idiot if the picture comes out fuzzy because of lousy focusing. Your wife will later nag you to see the results of leaving her alone all night, and your marriage may be headed for the rocks. You sacrificed her for 'blur'. Most amateur astronomers who give up the hobby are victims of FFDS - Fuzzy Focusing Depression Syndrome. I have found that knife-edge focusing is the ONLY guaranteed way of getting the focus right on. Hey, I have a Nikon F2 with clear focusing screen and 8X Peake Loupe on it. The knife-edge beats it every time. And I would be simply lost without using one with my Canon EOS DSLR. You can be near blind and still focus correctly! And for CCD use, the Series IV is still miles ahead of focusing software and using parfocal eyepieces. Take a look at how the Series IV comes out against MaxIm software here.
Q. Is the Series IV a true knife-edge focuser?
A. It sure is, but.... most users find that the new 300 line/inch ronchi screen will result in extremely sharp images and is easier to use than a knife edge. After using a ronchi screen, however, you may be curious to try our True-Knife Option which employs a true knife-edge. Real knife-edge focusing really is not for the uninitiated or faint of heart, but after practicing with a regular ronchi grating, you will know what to look for and become a whiz. Try one. You'll like it. Click here for a short tutorial on knife edge focusing using our True Knife Option.
Q. Do I really need the new 'Black Chrome' 300 line/inch screen?
A. The difference between our standard 180 line/inch screen and the 300 line/inch 'Black Chrome' screen comes down to the amount of interpolation needed when focusing. While focusing with a Series IV, you are basically looking for that point where the bars on the ronchi screen disappear altogether and you see only a shimmering whitish/gray area where focus is. There is usually a small play, however, between where the left bar and the right bar reappear on each side of focus. This is normally not much, so it is relatively easy to gauge the exact center point of the whitish area even with the 180 line/inch screen. The300 line/inch screen was developed for a number of reasons, mainly when strong focal reducers are used. The focal reducers tend to stretch the image out and, necessarily, the bars on the ronchi screen appear further apart making it more difficult to interpolate. Down to about f/6, users normally do not have any problems using the standard screen, but below that they may be wise to use the higher resolution screen. This has been especially successful with CCDs and f/3.3 reducers. But for simple 35mm photography, one does not have this problem. On the other hand, the Black Chrome screen does allow you to focus on dimmer stars and makes interpolating a lot quicker and easier even with 35mm cameras. So, if you simply want the best available regardless of what telescope you may come to own, get a Series IV with the Black Chrome screen. Read more about it here.
Q. Can I fine-tune the 'Stiletto' assembly myself and add different resolution screens?
A. Of course! We have made the Series IV utterly flexible so you can tweak it to your own satisfaction or for your own strange applications. (We even have Stanford Research Institute sending one to the Sun to take pictures of the photosphere!) Click here for instructions on how to easily tweak the system for you own use.
Q. Will you tell me how to make one myself?
A. No! How else am I going to save up for that new LX-12" scope? Besides, you will end up spending more on tools, finding suppliers, and messing it up in the end. Click above to see how the Series IV is manufactured to see what you'd be getting into.
Q. Is this an original design?
A. If original means stealing ideas from five other people and putting them together in a new way, then, yes, this is original. Credit has to be given to Jason Ware for the main idea. Credit goes to me for developing it so it works properly and looks nice. Thank Mr. Foucalt for the physics behind it all.
Q. Are there other suckers?
A. Yes, thousands! Below is a photograph from the very first victim of the Series I focuser, Dan up in Oklahoma, and what he had to say many years ago. The only complaint he had was that the picture came out blue. Sorry, I can only recommend buying Kodak film if you like blue, and Fuji if you like red, and saying a little prayer. Experimenting with other film helps too though! Since the introduction way back then, the Series IV has found it's way to all of the major continents - even Antarctica! And now with DSLRs, we don't even have to worry about film!
is blue! I dunno why. Maybe just the characteristics of the film. This is a 30 minute exposure. When compared to the 15 min. exposure I took, There is very little noticeable difference other than the nebula looks physically larger only because of the extra nebulosity captured on the outer fringes in the 30 min. exp."
Q. Can I use the Series IV for eyepiece projection photography?
A. While the Series IV was mainly designed for deep sky work, it can effectively be used to focus on the planets and Moon as well. In this case, the Series IV Stiletto bayonet assembly is unscrewed from the Series IV body and used separately. This is necessary since the diagonal and transfer lens assembly attached to the Series IV body forms a small telescope specifically designed to magnify the image on the ronchi grating. With eyepiece projection, using the complete Series IV unit would be similar to putting the end of one telescope up to the end of another. We all tried that when we were kids and know what happens. Using the Series IV modular mount assembly separately solves this problem nicely. But if you are truly into planetary photography, better check out our CVF 'Spotlight' Series of focusers since they were designed for planetary use from the ground up.
Q. How dim a star can I focus on with the Series IV?
A. The Series IV requires a pinpoint source of light which is viewable in order to function properly. (doh!) While it is possible to focus directly on magnitude 4 stars directly depending on your dark sky conditions and your own eyesight, this really is unnecessary. One essential to understand about focusing is exactly what you are trying to accomplish: Since your telescope's own focuser has no set stop at the infinity position like a regular camera lens, all you are trying to do is to determine the infinity position for it. To your telescope, any object over a few hundred feet away is considered at infinity. Thus, to your telescope/camera combination, it makes no difference if a star is 4 light years away or 4 trillion light years away. Both will use the same setting. In practical terms, this means that you can use a different star to set the focus and then retrain your scope on the exact object you will be photographing. As long as you do not experience significant mirror flop, or retraining your scope across vast areas of the sky, the focal point will be virtually identical. In short, with the Series IV you do not need to focus on the exact sky object you want to photograph. The case is similar for photographing extremely bright objects such as the major planets and the Moon. Just focus on a nearby star and retrain your telescope on your subject.
Q. How well does the Series IV work with newtonian reflectors?
A. It depends on the telescope's optical design. Knife-edge focusing is extremely effective for focusing SCTs with longer focal ratios, but falls short in some respects for small newtonian reflectors with low f / ratios. The problem usually boils down to limitations in the telescope design itself. All optical system designs are optimized for use over a fairly narrow range of focusing. This distance is roughly the standard length of a t-adapter (55mm) , plus an allowance for a typical camera's film/plane distance (30mm-80mm). In the case of an SCT, this design range usually extends about 20 centimeters behind the telescope and there are no problems focusing. In a newtonian design, however, this distance is intentionally made much shorter to minimize the effects of the secondary mirror obstruction. The result is that there may simply not be enough room to accommodate the additional length adapters and cameras take up without moving outside of the optimal design range. This may mean that you cannot properly focus a camera at all, or that the image you achieve may be substantially degraded if you are able to do so. Having said this, much depends on the design of your specific brand of newtonian and what it's design parameters were. If it was designed with astrophotography use in mind, the manufacturer has likely taken these facts into consideration If it was primarily designed for visual use, however, you may simply be out of luck using a camera effectively. Overall, for low f/ratio telescopes of any kind, you should seriously consider trying our Deluxe and Pro Edition models which incorporate the new Black Chromium 300 line/inch screen. This usually overcomes any problems.
Q. Why do I see a 'donut' when I'm focusing?
A. The donut you may see is a result of the obstruction of the secondary mirror in your SCT. This is normal. What you are more interested in is the lighted area surrounding the donut where you will see dark bars when you are out of focus. To reduce the donut problem, the Series IV transfer lens assembly can be intentionally set slightly off-center so that more of the lighted halo is shown than the black hole of the donut. This is one reason why the diagonal in the Series IV is collimateable. This also gives a better depth of field in the photo. Do not think that the diagonal mirror needs to be exactly centered. Doing so might center you on the central obstruction and actually reduce your view!
Q. I dropped a Series IV or CVF and smashed it to bits. What do I do?
A. You simply send it back to get fixed. I only charge fair shipping and the exact cost of repair parts for customers who stumble across the dog in the dark by accident. So, you don't need to trash the unit and order a whole new Series IV from us. We're not that kind of company. Then again, we're not Zippo either.
Q. Can I use the Series IV for solar photography?
A. Well... no. Hey, I never claimed that the Series IV could do everything! For solar photography, it is difficult to beat our CVF Series II which was designed in the first place to help focusing on bright daylight objects.
Q. I still have a question you haven't answered. What now?
A. Just click here to leave some feedback.
