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I have a C5 sct a ED80 and a RCT 8" f/8, I also use a canon 600da and a asi120 as a guide scope and I wish to photograph as many objects in the sky as my setup would allow. I've been doing 10-20 3min subs on each object and the weather has been kind enough recently so I have a fair bit now but I'm running out of the bigger ones. The obvious method is just cropping in processing but that would give less detail, a good example of the perfect size is crescent nebula. A bad example is basically anything that takes up less than 10% of the picture like the box galaxy cluster, eskimo nebula, fetus, snowball, cat's eye etc. I tried a 2x barlow on my rct but I need so many extension tubes that it would cause many problems, maybe a dedicated CCD camera will have a shorter fov?
This is a lens that does not need an introduction, it's simply a fantastic budget lens! I've been using it for astrophotography with great results and satisfaction (see pictures). Just selling it becuase I'm upgrading to the 135mm version. Any questions please ask. Asking £160 which includes P&P to UK mainland.
I have recently acquired a Vixen Polarie with the intension of doing some wide field imaging,
I will be using my modified Canon 600D with it, Currently the only lens i have are a standard kit Canon 18-55mm and a old carl Zeiss Jenna 50mm , so i am looking at purchasing alternative lens to use,
The ones i am looking at for now are the following,
Canon EF 135mm f/2 L USM
Canon EF 200mm f/2.8 L II USM
Samyang 135mm f2 ED UMC
Samyang 14mm Ultra Wide-Angle f/2.8 IF ED UMC
Sigma 150mm f/2.8 APO EX DG HSM Macro
Tokina 11-16mm f/2.8 AT-X Pro DX
So my question is, has anyone used any of these ( other than the Samyang 135mm f2 ) for wide field and if so how did you find them, would you recommend any of them?
from the ones listed (other than the Samyang 135mm f2 ) would you say there are better ones to look at or any other i should consider?
AZ mount recommendation for self steering high power UV laser calibration setup for a Cosmic ray observatoryBy CosmicRayResearcher
Hello! I am new here and have a kinda weird question for you guys.
I am a cosmic ray researcher with the Pierre Auger Observatory and I am building a UV laser system to calibrate some of our telescopes.
To do this, we need:
Self levelling powered steering AZ mount that hit point to the Zenith with high accuracy (most important) and also point to any zenith/azimuth angle we may need. It would be great if it worked well with Linux Battery power is a plus but we will have 24V DC available for the laser already so it is not critical Can handle a payload which is ~10kg and 40cm long Is less than 1000€ before tax Is there any really reliable option that meets this criteria?
The mount we are currently looking at is the iOptitron AZ Pro but this is just past the 1000€ mark we want to hit.
I am really new at this sort of thing so any advice you have would be greatly appreciated!
Here is a review and then a couple of questions to the forum
The experience I gained assessing my new Nikon Action EX 10x50s https://stargazerslounge.com/topic/369052-comparison-of-pentax-sp-50-wp-10x50-and-nikon-action-ex-10x50-cf/?tab=comments#comment-4009551 led me to dig out my old Vivitar Series 1 8x25. I bought these in 1995 for £99, so not an insignificant amount then. Series 1 was Vivitar's premium range at a time when (I believe) they were well regarded for their optics (now they seem to sell basically children's toy binoculars). Anyway, despite their price/apparent pedigree and excellent build (made in Japan) I never got on with them, finding them very difficult to focus and to keep in focus. They rarely got used and indeed got superseded for general use by the Inpro 10x50 mentioned in the thread above.
Using what I learned when assessing the Nikon's I decided that the focus problems were down to four things: 1. a small exit pupil, quoted as 3.12mm, so you need to have the eyepieces correctly positioned over each eye; 2. a short eye relief that I estimated to be about 11mm. I found the view (without glasses) to be best with the short (4.5mm) rubber eye cups folded down. Wearing glasses, it was like looking down a drain pipe with a severely vignetted view; 3. difficulties getting the interpupillary distance right: for some reason the image is significantly brighter when the binoculars are set wider than the correct distance. However, at this, what would appear to be the correct separation, they will not come completely to focus. When they are brought down to the correct distance (60mm for me) the image suddenly gets darker but actually focusses well; 4. a very 'low geared' focus wheel and seemingly very short depth of field which necessitates a lot of focus twiddling every time you change view (not for objects at infinity, obviously). Because of these things, its crucial to get the binoculars correctly positioned over the eyes and to keep them in that position. Once they are correct the image is actually not bad. To be specific, the image is almost exactly like it looks with the naked eye: the same colour balance, the same detail and resolution, the same clarity, the same brightness - just a bit bigger. Its quite uncanny really. In contrast, the Nikons give an almost hyper-real clarity, detail and brightness and as serious wow factor.
Compared to the 10x50s they really didn't seem to magnify that much (I found the objectives to actually be 23mm so 7.4x not 😎 but maybe this is something to do with AFoV. FoV is quoted as 'Wide Field 8.2°'.
So basically they magnify the image but not the brightness which is fine for daylight use but fairly useless as night. The big advantage, however, is that whereas the Nikon's are over a kilogram and will only just fit inside my zipped up coat when round my neck, these weigh a third as much (350g) and are a fraction of the size (105x120mm). They easily fit in my coat pocket.
So I think I should give them more of a chance by keeping them in my coat pocket so they are there when I need them (the best binocular is the one you have with you!).
On to my question then: does anyone know anything more about these older Vivitars: whether they are actually any good and when and why the company seemed to give up with proper optics? I can find nothing on the internet. All I have is the Vivitar brochure from the time (attached) in which the certainly seem to regard themselves as makers of 'proper optics'.
I'd also welcome comments on the issues I found and whether my conclusions are correct.