#1  
Old 24-11-2024, 06:30 AM
DebinOz (Deborah)
Registered User

DebinOz is offline
 
Join Date: Sep 2024
Location: Sydney
Posts: 17
New Petzval sv555 54mm from SVBony

https://www.svbony.com/sv555-astrograph-lens/#F9395A

Has anyone ordered one of these or have any feedback as to the quality compared to a Redcat or Askar? These are on sale right now and half the price of the Redcat. Too good to be true? They are not saying what type of glass they use and the marketing is hilarious. The guy in the release livestream even dropped it while demonstrating.
Reply With Quote
  #2  
Old 25-11-2024, 09:16 AM
OzEclipse's Avatar
OzEclipse (Joe Cali)
Registered User

OzEclipse is offline
 
Join Date: Jun 2012
Location: '34 South' Young Hilltops LGA, Australia
Posts: 1,395
Haven't ordered one. SV Bony are capable of producing excellent optics. I have a pair of SV Bony SV202 10x42ED's that are excellent.

For around that same price, you can get a Samyang/Rokinon 135mm f2, a fantastic tack sharp wide field astrographic lens. They are sharp wide open but with vignetting.

Add a quality 1.4X converter and you have a 200mm f2.8 and a 2X converter and you have a 270mm f4, not that different to the Redcat. Either of these will only have 45-55mm back focus depending which mount you buy so it depends what you want to hang behind it.
DSLR - no problems.
Dedicated Astrocam with filter wheel etc - you'll need to check back focus requirements.
Reply With Quote
  #3  
Old 25-11-2024, 03:45 PM
DebinOz (Deborah)
Registered User

DebinOz is offline
 
Join Date: Sep 2024
Location: Sydney
Posts: 17
Quote:
Originally Posted by OzEclipse View Post
For around that same price, you can get a Samyang/Rokinon 135mm f2, a fantastic tack sharp wide field astrographic lens. They are sharp wide open but with vignetting.

Add a quality 1.4X converter and you have a 200mm f2.8 and a 2X converter and you have a 270mm f4, not that different to the Redcat. .
I had a Samyang 135 and sold it to fund an upgrade to a longer focal length scope, being under the impression a telescope would yield better images at 250-400mm. I already have a 70-200 2.8L. To increase focal length I have been comparing a used 100-400 f4.5-5.6L, an f4 300mm, the Zenithstar 61 (F5.6, 360mm) and a refurbished redcat 51 (250mm, f4.9) I am using a full frame canon camera.

On paper, the 70-200 I already have looks like a winner at F2.8. Is the redcat or zenithstar going to yield better results?
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 05:41 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement