Astrophotography with a Small Triplet. Tecnosky 70 Review

In this video I will show the results that you can have with a small triplet telescope. This video is a telescope review of my first triplet refractor, the Tecnosky Apochromat 70/420 Triplet. I have tested this telescope in a bottle 4 sky, with and without reducer/corrector,(I tested with the 0.85x reducer corrector for the SV ED80/600) with no filters and also with Baader Uhc-s Nebula filter and Optolong L Enhance. An excellent choice if you are starting astrophotography or you are looking for a wide field refractor telescope, great price (under 600 euro).

The astrophotography images were very good, I have tested on nebulas, star clusters, galaxies and the Moon.

I was impressed by the quality and stability of the focuser, is a 2” rack and pinion that can carry loads up to 2kg and comes with a microfocuser 1:10 knob. The draw tube has also a nice pressure ring, and is very stabile. I was able to rotate or take out the camera from the focuser without losing focus.

I have tested first when changing the filters, however the baader Uhc-s Nebula filter and the Optolong L enhance do have a small focus difference, so i made another test with Optolong L enhance I just took the camera out and place it back having the filter one. I used for this tests a bahtinov mask and i made a fast focus because i had clouds, was not perfect but good for the test, the idea is to see if the focus will change or not. I tested this while testing the ha 7nm filter , and i forgot other exposure time in the second image with the Optolong L enhance but we can see that the focus did not change.

The stability and resistance to vibrations of this focuser was amazing!

A dovetail is still required for equatorial mounts, in my opinion because the base is short. I did not want to risk holding the short collar base at the limits.

I bought a dovetail from Lacerta but it did not have screws, ended up modifying the screws that i found, i had to cut them and make them shorter, best to have at least two screws that hold the dovetail and telescope together so the telescope will stay safe.

I liked the good image quality and good color correction, contrast and sharpness of this telescope. The FPL 53 glass helps this telescope obtain very good images free of false color.

Also being lightweight (1.85kg), you can use this telescope also with a star tracker and is easy to transport or attach on a tripod were also features that I did like.

Balancing the telescope on the mount was fast and easy to do. Balancing in Ra and Dec axis went well without any problems

You can find the Tecnosky 70/420 Apo Triplet at Astroshop.eu :

https://www.astroshop.eu/telescopes/tecnosky-apochromatic-refractor-ap-70-420-triplet-ota/p,57329?affiliate_id=NemesIoan

You can see also the images on my social platforms, and also the equipment used, in the links bellow.

G.A.M Astrophotography Club – Galaxy Art Media:

https://www.facebook.com/groups/4211944542182533

https://www.facebook.com/galaxyartmedia

https://www.instagram.com/galaxy_art_media/

https://twitter.com/GalaxyArtMedia

Messier 45 The Pleiades 21x30s Iso 1600 Nikon d7200 Tecnosky SLD 70/420 triplet

No filter, No reducer/corrector Mount Skywatcher Eqm 35 Pro

Sky with clouds and haze, that created some halos around big stars, bortle 4 sky.

Not using a corector we can see visible field curvature on the edges of the image, and elongated stars. A corrector or reducer/corrector is recommended to obtain a flat field image. With my reducer/corrector 0.85x for the Skywatcher Ed80 I bought also some extension rings that will reduce the distance from the reducer to the camera sensor and will improve the correction.

If you do not have already a corector, or you want to buy one for the telescope from Tecnosky I will link a reducer/corrector and corrector for the Tecnosky SLD 70/420 Apo Triplet :

0.80 reducer/corrector

https://www.astroshop.eu/flatteners-correctors-reducers/tecnosky-0-8x-four-elements-flattner-reducer/p,58722?affiliate_id=NemesIoan

0.80 Reducer/corrector that corrects the field up to full frame sensors

https://www.astroshop.eu/flatteners-correctors-reducers/tecnosky-adjustable-flattener-reducer-0-8x/p,68932?affiliate_id=NemesIoan

The Tecnosky Sld 70 does not have a dedicated corrector but should work good with the reducers/corector mentioned above.

Here is a link only with corectors so you can use at 420mm with a corrected field

https://www.astroshop.ro/flattener-corectoare-reducatoare/tecnosky-flattener-1x-2-/p,68836?affiliate_id=NemesIoan

And here is the link for my reducer/corrector for the Skywatcher aEd80 that i used in the video

https://www.astroshop.eu/flatteners-correctors-reducers/skywatcher-0-85x-focal-reducer-corrector-for-evostar-80ed-ds-pro/p,22262#tab_bar_3_select?affiliate_id=NemesIoan

In this cropped Image (from the original at 420 mm focal length without corrector) with the Pleiades we can see the stars elongated at the edges of the image

For all the tests i used my Nikon D7200 Dslr camera

The Orion Nebula, single exposure, with the Optolong L enhance and Tecnosky 70/420 apo, cropped (focal length used 357mm) 58 sec iso 100

Now we have a few images with Orion Nebula with and without the reducer corrector 0.85x (for the skywatcher Ed80)

In the first image i used the 0.85x reducer

Second image I used the native 420mm focal length of the Tecnosky 70/420 Apo Triplet Refractor

When i took the first tests with the Orion Nebula I had some clouds, and because of that we can see some halos around the bright stars.

After zooming in 200-300 % i observed some small diffraction spikes on the bright stars, this was hard to noticed, only if i zoomed in, and seems to be caused by the optics being just a little too tight,( many telescopes have the screws tighten to avoid decollimation during transport) This is a small issue, but it can be solved using the warranty or by removing the dew shield and unscrew the collimation screws and screw them again until they touch the glass.( I got this information from Tecnosky) I might attempt this in another video, or just use it like this since i was able to notice them only in some images zoomed in. I did observe similar diffraction spikes on other telescopes of other brands even expensive ones, I think is more of a luck situation, you might have them or not, but as i said before, is a small issue that can be solved or even ignored since the quality of this telescope was amazing.

Now let’s see also some longer imaging plans 42 min total exposure with and without filters:

Image I No filter 42 min Iso 800 F/5.1 Tecnosky SLD 70/420 at 357 mm focal length Nikon D7200

In the cropped image, we can see better the stars and details in the Orion Nebula and Running Man Nebula.

BAADER UHC-S NEBULA FILTER and OPTOLONG L ENHANCE at ASTROSHOP:

https://www.astroshop.eu/broadband-filters/optolong-filters-l-pro-2-/p,59435?affiliate_id=NemesIoan

https://www.astroshop.eu/uhc-filters/baader-filters-uhc-s-nebula-filter-2-flat-optically-polishes/p,10861?affiliate_id=NemesIoan

BAADER UHC-S NEBULA FILTER and OPTOLONG L ENHANCE at OPT:

Optolong L-eNhance Filter – 2"

Baader UHC-S Nebula Filter – 2" Round Mounted

Image II Baader Uhc-s Nebula filter 42 min Iso 800 F/5.1 Tecnosky SLD 70/420 at 357 mm focal length Nikon D7200

Image II Baader Uhc-s Nebula filter 42 min Iso 800 F/5.1 Tecnosky SLD 70/420 at 357 mm focal length Nikon D7200 Crop1

Crop2

Image III is a plan of 60 min total exposure Iso 800 F/5.1 using the Optolong L Enhance filter Tecnosky SLD 70/420 at 357 mm focal length and Nikon D7200

Now let’s see Pleiades and Mars Conjunction from March 2021

This image is a plan of 27 min total exposure with the Pleiades Star Cluster, i had more images but I selected the best photos and removed the ones with clouds from the stack selection. I Loved the final result after i finished processing.

Now let’s see also how this beautiful image with the Pleiades star cluster looks on print. I used my fine art printer to make an A3+ print on archival matte paper, and framed it:

Check my other astrophotography or painting, and let me know if you are interested in one or more of my prints

Let’s see more astrophotography images:

NGC 2264 Christmas Tree Cluster and The Cone Nebula 126 min total exposure with Uhc-s Nebula filter from Baader, Nikon D7200 and Tecnosky SLD 70/420 Apo triplet, using a 0.85x reducer/corrector

The next image is an excellent example on the field of view of the Tecnosky 70 apo refractor, using the 0.85 reducer corrector,with Optolong L enhance on the IC 410 in the left, and IC 405 (The Flaming Star Nebula)- in the right. Total exposure: 21x240s

Now let’s see more details in a crop of the image with IC 405 The Flaming Star Nebula

IC 1848 The Soul Nebula 40x240s Total exposure 2hr 40min with Optolong L enhance, Tecnosky 70 apo refractor, using the 0.85 reducer/corrector and Nikon D7200

The Rosette Nebula, 1 hour integration using Optolong L enhance and Tecnoosky SLD 70/420 at 360mm focal length with 0.85x reducer/corrector

I delete the part of the video with the Rosette nebula by mistake, but i might make another video instead. Here is a cropped image and we can see better the details:

Crop1

Crop2

Now i will show you also 2 star clusters, using the baader uhc-s nebula filter

Caldwell 14, Double Cluster 10 min Integration Focal Length 357mm

In this cropped image we can see the star closer

Messier 13, Grand Globular Cluster in Hercules 5min Integration(Total Exposure) Focal Length 357mm

And now let’s see a beautiful chain of Galaxies called the Markarian’s Chain in the Constellation Virgo, bortle sky 4, no filter, 12×4 min total exposure 48min, 357mm

The galaxies in the center are at about 52 million years ago and are called also the Eyes Galaxies

We have also a short plan of 21x60s iso 3200 total exposure 21 min, no filter bottle sky4 with Messier 81,82, Focal 357mm

and now a single exposure of 60s iso 3200 , no filter, bortle sky 4 Focal Length 360mm of M81 and M82

And Last we have a single exposure test of 20 min Iso 400 Focal length 357mm with the Iris Nebula, unfortunately i had haze so this affected the image quality. I used the baader uhc-s filter in sky bortle 4 with the Eqm35 pro mount and autoguiding, using my Nikon D7200

I do recommend you also the Skywatcher Eqm35 pro goto mount, as you also seen the results, the mount performed excellent.

You can find the Skywatcher EQM35 Pro GoTo Mount here:

Astroshop:

Sky Watcher EQM-35 Computerized German Equatorial Mount

https://www.astroshop.eu/equatorial-with-goto/skywatcher-mount-eqm-35-pro-synscan-goto/p,57352?affiliate_id=NemesIoan

OPT:

Sky Watcher EQM-35 Computerized German Equatorial Mount

All the images were stacked in Dss and processed in Adobe Camera Raw and Photoshop

Conclusion: After all this tests I do believe that this telescope is an excellent choice if you are looking for a good refractor triplet telescope for astrophotography. Good image quality and affordable price, good focuser easy to use and fast optics. Do not forget to subscribe also on my channel and click on the bell notification icon so you will not miss my future astrophotography reviews and tutorials. I wish you all clear sky!

http://www.youtube.com/c/GalaxyArtMedia