Reset Done
×

Corrective Optics

Robtics | Correction OpticsCorrective optics may sometimes be required to resolve specific optical abberations of mirrors or lenses.

Every refractor has a curved focal field and because the chip of a camera is flat, for good astrophotography the focal field must be flattened. This is achieved with a so-called Field Flattener.

Every reflactor suffers from coma to a greater or lesser extent. This is the optical effect in which stars closer to the edge are no longer pinpoints, but rather resemble comets. This can be solved with a Coma Corrector.

With a Focal Reducer, the focal point of a telescope can be shortened. As a result, photographic exposure is shorter and certain objects fits better into the field of view. Field Flatteners and Coma Correctors can sometimes also be a Focal Reducer.

The focal point of a telescope can be extended with the help of an Extender. This can be useful for increasing the magnification and correcting various optical errors.

Astigmatism of the eye can be compensated with Dioptrx from TeleVue.

A SCT telescope can be converted into a very fast photographic system with the help of a HyperStar.

Adaptive Optics can be used to minimize disturbing seeing effects during high resolution photography.

Can't find what you are looking for or need help selecting the most suitable correction optics for you? Contact Robtics! We are happy to help you!

Home

Last Reviews

Sky-Watcher Explorer-150P (EQ3-2) 150mm Newton Telescope

Read review

Paul B on Sky-Watcher Explorer-150P (EQ3-2) 150mm Newton Telescope

Grade:
Een droom die uitkwam. De opbouw was heel eenvoudig en binnen een uurtje stond hij. Ik ben hem zelf op wezen halen en wat een prachtig winkeltje en super vriendelijke en kundige mensen werken daar. De koffie was heerlijk en na het zien van wat er allemaal te verkrijgen is gaat de droom nog mooier en groter worden. absoluut 5 sterren waard. Dank jullie wel voor de hartelijke service.

Sky-Watcher Startravel-102T (OTA) 4" Refractor Telescope

Read review

Ad v on Sky-Watcher Startravel-102T (OTA) 4" Refractor Telescope

Grade:
Een handzame telescoop F5 een Rich Field telescoop voor groothoekobservatie . Gebruik een 8x50 zoeker en een 2 inch spiegel zenit Heeft iets last van chromatic aberration maar is niet hinderlijk en door gebruik te maken van de Baader Semi apo filter is de CA opgelost en geeft een rustig kijker beeld Ideaal voor het balkon deze kijker. Door John Baars kwam ik bij deze telescoop en heeft een leuke buitenlandse review geschreven. De levering door Robtics was goed en snel

ZWO Seestar S50 All In One Smart Telescope

Read review

Bas W on ZWO Seestar S50 All In One Smart Telescope

Grade:
De Seestar S50 maakt sterrenkijken moeiteloos, met indrukwekkende prestaties die zowel beginners als enthousiastelingen zullen bekoren. Nu nog heldere nachten en dan genieten!

iOptron Celestron AVX Adapter for iOptron iPolar

Read review

Paul v on iOptron Celestron AVX Adapter for iOptron iPolar

Grade:
Dankzij het geduld en uitzoek werk van Robtics blijkt dat ik nu mijn oude GPDX kan upgraden met de Ipolar d.m.v. de AVX adapter. Deze adapter past perfect op de GPDX. Installeren software en de Ipolar met adapter is een eitje. Nu nog wachten op een heldere avond. Robtics, bedankt voor de service met vriendelijke groet, Paul van Kuijk

ZWO Seestar S50 All In One Smart Telescope

Read review

Dianne E on ZWO Seestar S50 All In One Smart Telescope

Grade:
Vorige week de Seestar S50 ontvangen en gisteravond first light. Ik ben onder de indruk hoe makkelijk deze telescoop is te bedienen met de telefoon. Eerst maar eens naar het Andromeda stelsel, aangezien ik deze alleen als klein wolkje zie door mijn SCT8. Het automatisch uitlijnen ging perfect. M31 kwam precies midden in beeld van de telefoon. En toen kon het schieten beginnen. Maximaal 10 seconden per foto. Ik heb de sessie ca. 75 minuten laten lopen. Daarna de foto gewoon op de telefoon bewerkt. De foto stuur ik als bijlage mee. Eindscore: super, maar dan ook superblij met dit zeer handzame apparaat. Van alle gemakken voorzien voor een mooie prijs.

DayStar SS60-ds Solar Scout H-alpha doublestack Solar Telescope

Read review

Dianne E on DayStar SS60-ds Solar Scout H-alpha doublestack Solar Telescope

Grade:
Twee jaar geleden de Daystar SS60-ds aangeschaft. Helaas werkte de etalon niet naar behoren met als gevolg dat ik alleen maar een oranje bol zag. In overleg met Robtics de telescoop retour gestuurd voor reparatie. Uiteindelijk de Daystar weer terug ontvangen. Ik kon niet wachten op een zonnige dag en eenmaal daar de telescoop opgezet. En wauw, wat een beeld. Ik was verrast dat er zoveel ‘werking’ op de zon was. Beide chromosfeer en protuberansen duidelijk waar te nemen. Ik gebruik hiervoor een 40, 32 en 25 mm oculair. Ik ben super blij met deze Daystar SS60-ds. Graag wil ik ook de goede service, geboden door Robtics, noemen. Door hun hulp kan ik genieten van wat de zon te bieden heeft.

iOptron HAE43 Strain Wave Gear AZ/EQ mount with iPolar

Read review

Menno v on iOptron HAE43 Strain Wave Gear AZ/EQ mount with iPolar

Grade:
First experiences with iOptron HAE43EC, a short review. Although I own an observatory, sometimes I do put telescopes in the garden. To observe the sun in Ha or to visually enjoy the sky, while the scope in the observatory is imaging. I always used traditional GOTO mounts from Astro-Physics, Vixen and Losmandy, but those are heavy and cumbersome to drag outside. With the arrival of portable, lightweight harmonic drive mounts, I wanted to try out one of these. I mean, a mount weighing just a bit over 5kg, carrying a scope up to 20kg, without even the need for counterweights, it sounded magic to complement the heavy duty 10 micron 2000 mount I use in the observatory. I was hesitating between three brands: ZWO, Pegasus and iOptron. All three are capable of carrying the telescopes I use outside the observatory, and have more or less similar capabilities. Since I had good experiences with iOptron mounts, AND it is the only harmonic mount that comes with an intelligent handcontroller, eliminating the need of a PC or mobile for operation, I choose their HAE43EC. The EC stands for the encoder build into the RA axis. It should seriously reduce periodic errors in the drive. From an iOptron CEM40EC mount I used before, I know these encoders do work for unguided imaging up to a certain focal length. The HAE43EC has harmonic drives for both RA and Declination, eliminating the need of clutches or locks. Even if you lose power, the axis stay put as a safety mechanism. It can also be used in altazimuth mode for visual use, eliminating meridian flips. I have the mount installed on the light weight carbon tripod and a small pier extender go give extra height. The entire combo fits in a Geoptik bag. It is light enough never requiring to break it down into the three separate pieces. In between the legs of the carbon tripod, I have installed a triangular bag to put power supply etc. It also doubles as anchor to give more stability. Just throw in a few bricks if needed. The tripod is stable enough to carry my William Optics FLT91, a Takahashi FC100 or a Celestron C8 EdgeHD. If more weight is put on the mount, you may want to choose a heavier tripod. I have a heavy Berlebach Planet wooden tripod, to which I have made an adapter for the HAE43EC. The mount arrives in a small flight case, with the included power supply, the iNova hand controller and the iPolar electronic polar finder. Installing it on the tripod is a matter of screwing in a center rotation post and an azimuth peg. The mount itself attaches to the tripod with two bolts. A hex key is supplied in a magnetic holder inside the mount to firmly lock those bolts. The hex key is actually used as a lever through a lateral hole in the head of the bolts, so no fiddling in the dark is needed. First use, rough polar align At first I just pointed the mount roughly north, which is ok for casual visual use. There is no GPS, so you have to enter position parameters once. Same goes for date and time. You have to install a button battery (CR2032) which was not included. If you forget, it will require you to enter date and time each time the mount is powered on. About power: iOptron HAE43EC uses a 2.5mm DC connector, so standard 2.1mm DC connectors will not work. But you can get a 2.1 to 2.5mm converter at any electronics shop. After powering on, the mount does not yet track. You have to select and slew to an object, or go into the iNova settings menu to pick a drive rate. I observed the sun, Jupiter and Saturn in this basic alignment mode. Depending on your rough polar align, objects will stay in the field of view long enough for visual observing or a few webcam videos. GOTO operation is severely limited of course, and do count on being degrees off your target after a slew. Polar align and GOTO operation Yes, you can install the iPolar finder to the front of the mount, and use the iOptron polar align software to quickly and accurately polar align. I tried it, and it works fine as long as you are not too far away from the pole before you start (manual says max 7 degrees). Basically you have a cross and a circle in the PC app. The circle is the correct pole, and you move the cross towards the circle by using the mount altitude and azimuth knobs. If you get real close, the view is enlarged. If the cross is in the circle, they both become green and you are done. But all this requires a PC to operate. Which probably you don’t want if you are observing visually only. No worries, there is a very good and accurate polar align provided by the iNova controller. It is found under the Alignment menu. Actually it uses the two stars (no need to see Polaris) method, which is also described in the Astro-Physics mount manuals. When selecting the Polar Align option, the mount proposes a first star (you can scroll to another one should the first star not be visible from your location). After pressing enter the mount slews to the star. Obviously it will not be visible in the scope (unless you are very lucky), but it likely is in the finder scope. Using the altitude knob and the two RA buttons on the controller, you move this star halfway to the center (of finderscope FOV or main scope if it has a wide field). Press enter and the iNova will propose a second star. Press enter once more and it will slew to this star. Half center the star with the azimuth knobs and the RA buttons. After pressing enter, the mount slews back to the first star. Repeat this a number of times (3 times usually is enough) to get the alignment each time closer and closer to the pole. Once the polar alignment is done, you can start the goto system via Select and Slew. Planets, the moon, the sun, Messier, NGC, IC and comets are standard targets, but you can also enter coordinates for more exotic things should you want to. I looked for a 3 star alignment to create a sky model for goto’s, but that feature is not available. Which is a shame for such a mount. It seems iOptron decided to drop that feature from the recent iNova controllers. The reason is most photographers use plate solving nowadays. Not so great for visual observers… In fact, goto operation relies on accurate polar alignment and syncing to a target. After syncing, objects not too far away will be in the center of the field of view, but objects further away will not. Accuracy crossing the meridian will depend solely on the orthogonality of your optical tube. Observers who are using Astro-Physics mounts will recognize this… It is actually the same way the GTOCPx controllers of AP work since years. Roland Christen of AP wrote pages on how to make your tube orthogonal to the mount instead of providing a simple software solution. But a three star align with extra alignment stars would just make it that much easier. File complaints at iOptron to get the feature back ? It is a small restriction for now we have to live with. Basically you need to sync to a target before moving to the next, or sync to a bright known star near your target first. The HAE type mounts of iOptron can also be used in altazimuth mode. In that case of course no polar alignment is needed, and the goto's will depend on the mount being as level as possible and the sync operation. Mount capacity I have not pushed the mount to its theoretical limits yet. The heaviest scope I used is a Skywatcher 180mm Maksutov, be it a super-heavy edition of this scope. With large solid tube rings, dual plates and the rings it brought the center of gravity 5cm further out from the crossing of the axis. So I would rate it the same as a Celestron C9.25 weight and size. This gave no issues at all for the HAE43EC, even on the carbon tripod. I think it is fair to say a Celestron C11 will work provided you use a heavy-duty tripod like a Berlebach or the iOptron TriPier/LiteRoc. The HAE43EC features an optional counterweight shaft and weight. It is not yet needed for a vanilla C11, but you might want to consider installing it if you start to add accessories to the telescope. Tracking has been very good with all telescopes I have used on it. Visually I did not see large periodic errors, and backlash is virtually zero. WIFI operation The iNova controller has built-in WIFI. On my mobile phone I use Sky Safari Pro, and gave it a try with the HAE43EC. You have to select CEM120 in the Sky Safari telescope settings, give the IP address and port found in the ASCOM and WIFI manual, and there you go… The universe at your fingertips. Conclusion The iOptron HAE43EC is a very capable little mount. Biggest advantage is of course the weight and size factor, especially if you travel to dark skies. But the mechanics are excellent, and the iNova controller offers enough features to keep visual observers busy for years. Depending on the gear you want to put onto the mount, either pick the lightweight carbon tripod or a more heavy duty one. Overall: so far I am very satisfied with the mount.

Sky-Watcher Heritage-150P FlexTube 150mm (6") f/750 Parabolic Dobsonian Telescope

Read review

Mike K on Sky-Watcher Heritage-150P FlexTube 150mm (6") f/750 Parabolic Dobsonian Telescope

Grade:
mooi en makkelijk te gebruiken leuke beginners telescoop, laat met een paar extra lenzen heel veel zien.
Product added to wishlist
Product added to compare.