Upgrade Project
* 4mm eyepiece
* 10mm eyepiece
* 23mm eyepiece
* Finderscope
* Astro Cam
Upgrades
All lightweight components are the key to upgrading. The Celestron FirstScope has a fixed OTA with no provisions for adjusting balance. Therefore, any accessories added will need to be very light weight.
Discard Plastic Lens Eyepieces
The tiny 3" Celestron FirstScope needs an immediate upgrade out of the box. First, throw away those nasty plastic lens eyepieces. They only help to degrade the image. Ours melted on a hot summer day! (see FirstScope review)
https://otisastro.blogspot.com/2020/08/celestron-firstscope-my-review.html
New Eyepieces
You also want these low profile eyepieces so their tube structures do not dip down into the telescope and obstruct the mirror. (see measurements photo) The eyepieces are less than an ounce or less than two ounces depending on their focal length (see chart), fitting our nearly weightless requirement to keep the telescope well balanced. The 23mm is about $11, the 10mm is $12.20 and the 4mm is $12.60. When other eyepieces have astronomical costs, these fit the FirstScope budget!
One thing we like about these EPs is they let through a lot of light with their ultra wide diameter lenses. The simplistic optical arrangement is a spectacular performer and matches the FirstScope's short focal length (about 12-inches at F4). The coated optics reduces reflections. The reflections we had came from the multiple complex lenses in the Apple iPhone cameras.
FinderscopeNext, the telescope needs a finderscope but again, one that's nearly weightless. I managed to find an original OEM replacement at 5x by 24mm diameter, to the one in the upgrade kit originally offered by Celestron. This plastic finderscope comes from China, same as the telescope, weighs only 1.8 ounces and costs less than $5! It fits the minuscule little telescope perfectly. If you buy it in the Celestron package it will cost almost $30. The mounting bolts are already on the OTA and the finderscope attaches instantly. It's a piece of cake.
Astro Cam!
Last but not least is the addition of a slick astro cam. This one is ultralight and is like the eyepiece, weighing less than 2 ounces. It runs on an older Mac laptop. The advantage of using a cam over the iPhone is the light weight and the image is large when spread out across a computer screen. This helps focus, centering, etc. The cost is extremely low as this was a USB cam purchased a number of years ago. As used computer equipment, it produces outstanding electronic images, has an automatic exposure and gain circuit, has software with controls, and the front lens is fully adjustable that can be set to infinity. Logitech and third parties may no longer offer free drivers for new PC and Mac computers with new OS (for old cams). These OS get updates every 2 or 3 months these days! However, an old Mac laptop will do the trick.
Suggestions
Another alternative is to buy new on budget - for $33 a USB 2.0 Wansview webcam is available at 1080p, 30 fps, and 90 deg. fov. It has audio for recording details about the exposures. Another is the Hrayzan for $49 - it has an extra wide fov. Note the camera mount made from a few rubber bands, again weighing next to nothing.
Electronic EyepieceNow that technology is changing at the drop of a hat, with costs that have little regard to those on a budget, let's take a trip into the lesser tech world for some things that fit perfect on our budget telescopes. If a new cam is too much for the budget, a more cost effective approach is to try out a CMOS electronic eyepiece for a PC laptop. Costs go down to about $5.65 for a Windows OS unit. These are sold unvetted from China by many trade names.
The cost is down also because these sensors are small (4.86mm x 3.64mm) and do 640x480 at 15 fps and 320x240 at 30 fps, yet operate at 24 bit RGB. Sample images supplied by the seller at left with a 3-inch telescope and the electronic eyepiece show lunar and planetary color.The Moon image has some image processing to remove spots, increase contrast, crop, sharpen, and flip the image to the correct orientation. Saturn is a raw image. Both are in full 24-bit RGB color. The photos were taken without any calibration frames, i.e. dark, bias, flat, etc.
Celestron FirstScope - Index
https://otisastro.blogspot.com/2020/08/celestron-firstscope-index.html
