Crescent Nebula,... first test with my new scope

Hi all,


This is my first serious test of my telescope, TS Optics 90mm FPL55 APO Triplet, it was average condition seeing and weather that night, but the scope is just ..... WOW.

I struggled as usual to be ready in right time and i ended up like almost 3-4 hours, so i gave my Ha filter more time than OIII, i can say that it was another test for my OIII 3nm filter since 2019, and WOW, the filter just delivers nicely.


The target was Crescent Nebula, because i was after using only 2 NB filters and not SHO, so this is HOO of it as a test, i am quiet happy, i know it needs more time and care, but this is definitely better than what i did last years anyway.

Equipment details:
TS Optics 90mm F/6 APO Triplet FPL55 + Stellamate 0.8x reducer
ZWO ASI1600MM + ZWO EFW 8x1.25"
AZ-EQ6
QHY mini guide scope + QHY5L-II-M
Gain = 200, Offset = 50, Temp = -5C
Astrodon Ha 5nm = 28 x 300sec
Chroma OIII 3nm = 15 x 300sec
20 Dark, 50 Bias, 50 Flat
EQMOD, Pegasus PBA, new Bahtinov mask
Acquisition and processing: SGPro, PixInsight, Photoshop CC
20 May 2021
Bortle 8

Very nice, you've brought out detail around it quite well.

What's the focal length of the OTA? being a 90mm objective I'm guessing circa 900mm?

xa-coupe wrote in post #19241067
Very nice, you've brought out detail around it quite well.

What's the focal length of the OTA? being a 90mm objective I'm guessing circa 900mm?

Thank you very much!

It is 90mm F/6 which means its focal length is 540mm, but i used a reducer with it which is 0.8x, and that made the scope to be 432mm F/4.8, i shouldn't use a reducer so i can get more close up to this target.

Tareq wrote in post #19241451
Thank you very much!

It is 90mm F/6 which means its focal length is 540mm, but i used a reducer with it which is 0.8x, and that made the scope to be 432mm F/4.8, i shouldn't use a reducer so i can get more close up to this target.

Thanks, not as long as I was thinking ... If that target is available in the southern hemisphere I might give it a go.

xa-coupe wrote in post #19241558
Thanks, not as long as I was thinking ... If that target is available in the southern hemisphere I might give it a go.

You also have targets that we dream about such as Liberty Statue nebula and dragons fighting nebula.

Statue of liberty is good, though I think my 380 FL is a bit short for it .. not tried the fighting dragons yet!

xa-coupe wrote in post #19241558
Thanks, not as long as I was thinking ... If that target is available in the southern hemisphere I might give it a go.

I think you'll have a bit of trouble with this target from your location.
Right ascension 20h 12m 7s
Declination +38° 21.3'

From Melbourne it's 13° above your horizon as it crosses the meridian to the north. Not impossible, but it will be low. I managed to shoot Centaurus A when it was only 6° above my southern horizon.

You've done more research than me!! I won't be able to get it from home as I can only image to the south due to my house being in the way. One day I will get out to a dark sky location and go nut on things like this.