0.00
#...
·
·
1
like
|
|---|
|
Hi guys. I'm near to pull the trigger on a new wide field OTA for nebulae season to use with my trustrd ASI 1600 mm and Antlia filters. Targets will be mainly dark and reflection nebulas with some NB in between. I already decided for the Fra 400 with reducer, but the last Dark Rangers video on youtube mixed the cards again. He let me notice that askar does not declare wich ED glass uses on the Fra scopes. So I'm looking around again. A lot of people here on AB enjoy the FRA, the 300 and the 400. But someone experienced also bad chromatic aberrations. The keyword are: pretty light weight (i'll use it on its own for the next season, but in future I'm planning to install it on a 10" newt as second rig), focal length around 280-300mm, pretty fast (i'm in doubt about the fra 300 for that reason) and with a good quality focuser (it will be installed on a 10micron mount and run unguided so flexure are not welcome). Budget around 1500-euros, the same price tag of the FRA 400 + reducer. Any suggestion? |
5.01
#...
·
·
3
likes
|
|---|
|
I'm very happy with the performance of my FRA300. I use it with an ASI2600MM. Star shapes are pretty good. I also have another setup composed by a FSQ106 EDX4 and FSQ85. The FRA300 is a good budget choice with good quality optics. My unit came out really good. About if it's fast... for me it's fast enough because I have it in my backyard observatory. If I compare it with my new Sharpstar 13028HNT, it's another league... but the stars quality on the newtonian are really worse... nothing compared with the pin point star of the FRA300. I attatch several results: https://astrocat.info/the-cocoon-nebula-ic-5146/ https://astrocat.info/the-heart-nebula-sho-ic1805/ https://astrocat.info/a-deep-andromeda-galaxy/ Best wishes, Aleix Roig |
0.00
#...
·
·
1
like
|
|---|
|
How about the Askar 65PHQ with 0,75x reducer? It is light and in terms of price near the FRA400. Also you could have a look on the redcat 61. |
0.90
#...
·
|
|---|
| I agree with Armin. The Redcat 51 has great optics, super portable, and trouble free. I can also easily accommodate a variety of sensor sizes. Some of my best images to date were captured with the Redcat 51 coupled to the ASI 2600MC Pro. |
|
0.00
#...
·
|
|---|
|
Thank you for your replies. @Armin Lukas , can't find the advantages of the Sharpstar 65 over the Askar. As far as I know, the glass is a generic ED too, the F-ratio is slower and the focal length with the reducer is almost the same of the FRA 300, but with the latter there's no backfocus due to the petzval design. Maybe I'm missing something. The Redcat is definitely an option, I've no experience with the belt focusing but I'm pretty sure it will work fine. My only doubt concerns the mounting plate: I saw many redcat installed on a 3d printed raiser to accomodate the EAF. For me this is a weak point because I'm trying to avoid flexures. I also found a Borg fl55. Any of you has experience with it? |
|
0.90
#...
·
|
|---|
| Check out the ProAstroGear EAF focus adapter for the RedCat 51. Autofocus with no problems. Only downside is that the dew shield remains in place for travel. |
6.71
#...
·
·
2
likes
|
|---|
|
I compared the FRA300 to the Redcat 51 a while back: https://youtu.be/5h_2D1cP578?si=Ol3Yo5m6Rs0tg75R&t=547 Very similar in performance IMO. Back then, I'd give the FRA300 the edge because I prefer the traditional focuser, but now the new Redcat V3 has a regular focuser knob so it's a toss-up, and I'd just get whichever focal length your prefer 250 vs. 300mm. FRA series reduced is great for narrowband, I've been less impressed with broadband capture, too much CA compared to the f/5 scopes above. My 2 cents, Nico |
5.72
#...
·
|
|---|
Armin Lukas: I have been pretty happy with my 65PHQ (ZWO version in my case). Even with a full frame DSLR it does really well. Here is a sample image of Carina with the reducer and a 533 OSC sensor: 15hrs Carina OSC 533 and reduced FF65 |
|
5.72
#...
·
|
|---|
Aleix Roig: I saw your work from Namibia with the FRA 300. Just outstanding. |
0.00
#...
·
·
1
like
|
|---|
| You should decide what's your preference. Of course some of the best F/5 - F/6 scopes give little better optics quality than FRA400 with F/3.9 reducer. But F/3.9 scope is double faster than F/5.6 scope and more than 1,5 x faster than Redcats. I'm very happy with my FRA400 and reducer. Maybe stars are too often too sharp and small so you have to drizzle, but that's first world problem! |
|
0.00
#...
·
|
|---|
Nico Carver: Hi Nico, thank you for your answer! Of course I've already seen your video, that introduced me in the FRA world. I would like to thank you for your beautiful channel, which I follow with pleasure. In my case, broadband performances is really important because the setup will be installed in a remote hosting site under bortle 2 sky, from which I would like to shoot all those targets that I have always dreamed of but were impossible from my bortle 6-7 sky. I'm actually considering throwing away my NB filters  . More than that, Redcat V3 is impossible to find in Italy and I do not want to buy abroad for obvious warranty reasons. I would like to ask you with which sensors did you test the reduced FRAs. I will use fairly small sensors (1600-294 mm). If you used APSC or full frame sensors, CA could be more pronounced. Am I right?@Tommi Liinalampi your pictures with the FRA 400 are really amazing. More than that, I actually assume to use the new scope with the 1600mm because sampling looks better, but I also have a 294mm so I could duplicate your setup. I do not seen CA, do you use BXT or other postprocessing techniques to let them disappear? Or in your opinion is due to small sensor area? |
|
6.71
#...
·
|
|---|
Leonardo Landi: Yes, I have been using the FRA500 with f/3.9 reducer with full-frame cameras (ASI6200MC and MM). With a smaller sensor you are only capturing the most corrected part of the field so star performance will be better in the corners when using a smaller sensor. As Tommi says, it's a tradeoff, you gain almost a stop of light with the reduced FRA series. Depending on your style of imaging and processing, you may prefer one or the other. |
|
0.00
#...
·
·
2
likes
|
|---|
| Hi guys. Thank you for your replies. In the end I decided to pull the trigger on the 400 with the reducer. It's faster, the weight is more or less the same and the rings looks more solid than the "shoe" of the 300. |
