It’s been a few months since I’d reviewed a product, not because there isn’t anything new out there – but because I like things I can get excited about. Sure, I love fine, expensive optics, exotic telescopes and tech toys, but isn’t the whole point of asking for a product to use and abuse to give you an idea of what’s worth your hard-earned money and what isn’t? Yeah, I thought so, too. That’s why when I began researching Celestron products for “Guide To Space”, I knew I had to get my hands on one these to check out…
While the little kid in me still loves to get packages in the mail, the astronomer in me loves to open them up and see a brushed aluminum case inside the cardboard box even more. For those of us into the telescope game, we treasure cases of any kind and I have a wide collection of them – from discarded make-up kits to plastic power tool castoffs. I’ve found the object is to protect my equipment. While it doesn’t matter if one of my old sets of tripod legs fit great in an old tent pole bag, I’ve noticed it sure makes my heart beat a lot quicker if the case is shiny and has the manufacturer logo emblazoned on the front!
I wasn’t disappointed when I opened it either. The aluminum accessory case is well constructed with reinforced edges and corners, the hinges operate smoothly, the handle isn’t going to just come off and the latches are secure. Inside is lined with dense foam with circular cut outs for the included eyepieces with room for more and a rectangular cut out for the filters in their cases. First test? Ooops. I just dropped it from a height of about a meter and a half onto a hard surface and it didn’t pop open. Second test? I could set it on a hard surface and open it up and it didn’t flop over. Third test? Yeah. Everything inside was still where it was supposed to be! So far… So good.
There’s a very good reason why I’ve referred to the Celestron 94303 Eyepiece and Filter Accessory Kit as a “telescope tackle box”. Like the many compartmentalized fishing buddy, this kit contains a wide variety of celestial “lures” that serve an even wider variety of purposes. Let’s take a look at each one and what I encountered over several days and times of viewing different objects:
The least magnification factor of all the 1.25″ barrel eyepieces supplied here is the Celestron 32mm plossl. It’s an absolutely classic 4-element design and has a 44 degree apparent field of view, so how does it perform? With my 900mm focal length reflector is providing around 28X magnifying power. This gives outstanding view of wide field subjects such as the Orion nebula complex, the Plieades and combinations of objects such as M81 and M82… including great full disk lunar. The coatings perform very well and so do the optics. I don’t pick up any severe flaws at the edge of the field, the color correction is bright and clean (Orion nebula is grey/green as it should be, and the Plieades are blue) and the Moon doesn’t display reflections. In a 660mm focal length refractor, we’re only getting about 20X magnifying power and the 1525mm focal length reflector gives me about 48X. At all ranges, the Celestron 32mm plossl performs just fine and the eye relief is excellent.
The next up is the Celestron 15mm plossl and a jump to about a 52 degree apparent field of view. First choice is the 900mm focal length reflector and a magnifcation factor of 60X. This is a little bit stronger than what I would have preferred for a mid-range magnification factor. For the 660mm focal length refractor, it provides 44X which is much better. This still keeps the Moon at a full disc and larger objects within range. However, in the 1525mm focal length reflector, it provides just over 100X – but at a great eye relief with bright, non-vignetted edges. This makes the 15mm plossl an exceptional large galaxy study eyepiece and makes small nebula nice and bright. Again, the color correction is outstanding and there are no spurious (optically caused) reflections around bright stars like Sirius.
Now for the 9mm Celestron plossl. Into the 900mm focal length reflector it goes. Eye relief is marginal, but it does still carry the nice 52 degree apparent field of view at 100X. It’s showing me the same performance properties of the 17mm in a longer focal length telescope – but with less eye relief. In the 660mm reflector it provides 73X, which means you’re sacrificing some eye relief to get the magnification, but the images are still surprisingly bright and no coma at the edges. In the shorter focal length telescopes, this is a good galaxy study eyepiece and does surprisingly well a small bright nebulae, too. In the 1525 focal length reflector it gives around 170X which makes it just dandy for smacking resolution out of globular clusters and studying galaxy details while still keeping the object bright. This is also a great range for the longer focal length to use for lunar and planetary studies because you’re not hammering the magnification so much that the least atmospheric disturbance is so noticeable.
Ready for more? Then let’s go for the Celestron 6mm plossl in the 900mm focal length reflector. This gives 150X magnification factor and no where near the scope’s practical limits. Even though the apparent field of view is still good, the eye relief is beginning to really suffer. However, I am quite surprised to see the image remains fairly bright on galactic studies. In the 660mm focal length refractor I’m getting 110X, and while this scope isn’t a “light bucket” this magnification range make the scope rather exceptional on pretty double stars, lunar and planetary details. For example, Iota Orionis was easily split and very beautiful, it was possible to see glimpses of the Cassini division in Saturn’s rings and Comet Lulin filled the field! As far as performance is concerned, put the 6mm plossl in the 1525mm focal length reflector and you get 254X. Go on… Take a look at the Trapezium. You’ll see red and blue stars!
Last, but not least is the Celestron 4mm plossl. In the 900mm focal length reflector you get 225X. This is hammer time for lunar and planetary details – as well as double stars. The eye relief isn’t any worse than the 6mm, but you’re pushing the magnification to the point where the least atmospheric disturbance really begins to show. In the 1525mm reflector, this means 381X and just around half of what its practical magnification limits are. At this point, you are also dimming the image as well. In the 660mm focal length refractor it’s producing 165X and pushing it to its limits. While I’m getting nice airy disc, it just seems very “on the edge”.
When it comes to the eyepieces included in the Celestron 94303 Eyepiece and Filter Accessory Kit, I found all of them to perform very well in every telescope I chose. You must remember the magnification factor of any eyepiece is the focal length of the telescope divided by the focal length of the eyepiece – and that every telescope has a practical magnification limit. You must also consider that while the same eyepiece performing at 100X in one telescope, will not perform like a similar 100X power in another telescope because each telescope is capable of different resolution factors and light gathering ability. With this in mind, know that each one of these eyepieces normally retail for around $45 a piece, are threaded for filters, have protective caps, produce a nice, flat field with no screaming vignetting, good color correction, excellent contrast and decent eye relief. In my book, that makes them a valuable asset to any eyepiece collection.
How about the barlow lens? Yes! There’s a 2X Celestron Barlow Lens here, too! For those of you who have never used a barlow, it’s a down and dirty, quick and convenient way of doubling the magnification power of any eyepiece – and preserving the eye relief. For example, and without being redundant, you can take any of the eyepieces reviewed above and simply double the magnification power when you place the barlow lens in the focuser before the eyepiece. In certain circumstances, this doesn’t seem to make a whole lot of sense to me because the wide variety of eyepieces included drop almost accordingly, but there is a marginal difference. Considering the barlow is an exceptionally useful tool to have in any astronomy kit and the fact that you might prefer the magnification factor and eye relief of say… the 15mm coupled with the barlow over the 8mm… it’s great that it’s in there! At around $40, the fully multicoated lenses certainly won’t cause any image degradation and the barlow just might be your cup of tea!
Now for the filters… 1.25″ glass telescope filters included with the Celestron Eyepiece and Filter Kit include Kodak Wratten #12, #21, #25, #56, #58A, and #80A. That’s awesome… But what do they do? First, let’s start with how they work. On the open end of the eyepiece barrel you’re going to find threads and these filters simply screw into these threads. What’s more, you’ll find the filter cells are also threaded to be connected to each other, so it is possible to “stack” filters. Using color filter with a telescope takes experimentation, and while you can recommend what each one is used for – only you can ultimately decide what works best for you! Each individual filter comes packaged in its own plastic padded case and they retail for around $15 a piece.
When it comes to #12 Yellow, you’ll find it reduces light transmission to 74%, thus helping to reduce glare around bright subjects such as the planets and Moon. It is known for enhancing orange and yellow features, and contrasting blue and green – such as those on Jupiter and Saturn – as well as giving nice contrast on lunar subjects. #21 Orange drops light transmission to 46% and blocks transmission of blue-green wavelengths. This means you’re going to enjoy this particular filter for seeing edge of maria detail on Mars (when Mars is close enough and big enough to enjoy) and it will improve some details in the equatorial belts on Jupiter and definitely make Saturn’s planet on the rings and rings on the planet shadow more defined. #25 Red only allows 14% of the light to come through, and this dandy little filter works well with large aperture scopes for seeing Mars polar caps and really rocks for digging unusual details off the lunar surface and helping to pick out Venus phases. #56 Light Green is a great all-purpose filter, allowing 53% transmission and works very well with Mars polar caps, Jupiter details and fine lunar details. It’s also a great “stacker” to enhance other filters, too. #58A Green gives 24% light transmission and it’s the world’s best set of telescope “sunglasses”. While it will help pick out odd ball features on Saturn, what you’ll find you use it for most is turning down the photons when observing the Moon and Venus! It also works very well in conjunction with a white light solar filter to help relieve eye strain while sketching. #80A Medium Blue is also another “classic” color filter. It provides 32% light transmission and although it will dim out other details, you’ll find it really helps when it comes to spotting the Red Spot and shadow transit events on Jupiter… and can even help distinguish differentiations in Saturn’s cloud patterns. This particular filter makes long-term lunar studies very eye friendly!
Last, but not least? The neutral density filter. Like its predecessors, it retails for around $15, is threaded on both sides, made from high quality optical glass, fully coated and has about a 13% transmission factor. What makes it different is 0.9 density, which means it’s reducing glare while transmitting light in a uniform manner across the entire spectrum. While it appears to have a gray color – its color isn’t affecting the wavelengths of light. That makes the neutral density filter an exceptional tool to have in your kit, because it can be used to help “tone down” disparate double stars, take the edge off the Moon when watching an occultation, shave some of the light off Venus, enhance bright stars, and become a lunar, solar and planetary observer’s best friend. While it is often simply just called a “Moon Filter”, you’ll find that you’ll use this particular little disc more than any other over the years. So often, in fact, that you may often wonder why that galaxy looks so dim only to discover you’ve forgotten to take it out of your favorite eyepiece!
All in all, if you were to purchase each piece of the Celestron 94303 separately, you’d have about $365 in all of these cosmic lures. So, what does the Celestron Eyepiece and Filter Accessory Kit retail for? Try $139 plus shipping. Sure, you could go fishing for the stars with just the eyepieces included with your telescope and you’ll catch them… But sooner or later, you’re going to want to start adding other things to your telescope tackle box – and lasting value and practicality are going to be a point to consider. While these aren’t “prestige” products, they are well constructed, optically well above satisfactory for the price and one of the best daggone values I’ve seen in a long, long time…
Way to go, Celestron…
My many thanks to Oceanside Photo and Telescope for once again providing us with a review product. It is very appreciated. I encourage all readers if you chose to purchase this kit from OPT, to be sure to place “Universe Today” in the club affiliation section when ordering to receive a discount on your final bill.