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Astroscope + DSLR = Setups! (1 Viewer)
- Thread starter cango
- Start date
I just need some help finding the right mount for the new camera I'm about buying.
It's the Sony SLT A65V.
My first choice was the Nikon D5200 but unfortunately it doesn't come with Focus Peaking. Second was a Canon 60D which Firmware can be tweaked to have FP, but finally I decided for the Sony.
So what Adapter/Mount do I need to use it on my Scope (Astro Professional ED80)?
The Sony uses the Minolta A-Bajonet, right? But I can not find it here:
http://www.astroshop.de/teleskop-zubehoer/astrofotografie/t-adapter/15_35_50
Any help would be much appreciated.
Thank You,
Frank
It's the Sony SLT A65V.
My first choice was the Nikon D5200 but unfortunately it doesn't come with Focus Peaking. Second was a Canon 60D which Firmware can be tweaked to have FP, but finally I decided for the Sony.
So what Adapter/Mount do I need to use it on my Scope (Astro Professional ED80)?
The Sony uses the Minolta A-Bajonet, right? But I can not find it here:
http://www.astroshop.de/teleskop-zubehoer/astrofotografie/t-adapter/15_35_50
Any help would be much appreciated.
Thank You,
Frank
Tord
Well-known member
Hi Jules,
I just checked:
Focuser fully extracted + 2" barrel: 105mm (of which the focuser is 75mm)
Tube: 404mm
Front hood: 137mm
PS I measured a scope with single speed Crayford focuser.
JGobeil
Nature Photographer
Thanks Tord,
I have never seen the scope so I don't know how it is made but I want to know if it will fit it inside a 48cm high (ID) photo backpack. I can get one with the dual speed focuser for a good price. It is the basic scope with focuser stripped of options like mount, diagonal, eyepiece, finder, etc. but I don't need those.
The measurement I need is with focuser installed but tucked in to be minimal size, no accessories attached to the focuser, with hood removed or retracted if that is possible - protection caps at both ends.
Yours has the single speed focuser. Maybe someone who has one with the dual speed focuser can give me a measurement.
Thanks
Jules
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Tord
Well-known member
Hi Jules
Now I see what you are after.
Earlier in this thread there are some pictures of the SW80, I know I posted some about a year ago (look for posts written by me).
Here are some more recent pictures showing the SW80, both an overview and some details.
http://e-group.uk.net/forum/showthread.php?p=230901#post230901
The minimal length would be:
404 mm + 30 mm + ~5 mm = 440 mm
The 5 mm come from a plug the end to avoid dust.
Note that since it is wrapped in camo tape one detail is not clearly visible and that is where the tube ends and where the front hood starts. Look at picture #1 and you get an idea where it fits. The front hood is easily un/mounted. One detail: the front cap that comes with the scope is designed to be fitted on the front of the lens hood. So you will have to fabricate one, which should not be too difficult, perhaps out of a 4" PVC pipe ending, shaping it with heat air gun for good fit to the tube. This will add another few mm.
So I would say that in total the length is between 44 and 46 cm, focuser retracted, lens hood off, plugged at the read and some suitable cap at the front.
Regarding the focuser: I don't think there is a difference in length between the single and dual speed, the difference is the extra gear inside. For our application area the single speed is enough. But someone else should confirm the length.
HTH
Tord
Last edited:
Paul Corfield
Well-known member
Retraction of the hood isn't possible, it's just a push fit on the front. Fernando made a really nice retractable one for his and he possibly still has the plans for the design.
Paul.
Paul.
JGobeil
Nature Photographer
Thank you guys. I've seen a lot of pictures of this scope but it is difficult to have a good idea without handling one. I couldn't know how far the small part of the focuser retracts inside nor could I see if the hood is retractable.
Now I know I can fit the scope in the backpack but I'll have to find room inside for the hood and it is quite big...
A retractable hood is nothing more than a slightly larger tube with felt like material inside so that it slides easily on the telescope. The screw-on rings at each end limit its play.
Now I know I can fit the scope in the backpack but I'll have to find room inside for the hood and it is quite big...
A retractable hood is nothing more than a slightly larger tube with felt like material inside so that it slides easily on the telescope. The screw-on rings at each end limit its play.
Miles Green
Active member
Hello again!
So i got myself a telescope. Based on many recommendations (thanks everyboddy!) i decided on TS APO 80/500 super-APO triplet. I should point out at this point that I am allergiv to fringing and longitudinal chromatic aberrations, so i went for the full APO.
When i first opened the package, i was a little in shock... these scopes are BIG! Thanks to everyone who talked me out of a 120/900! Indeed, magnification, especially on a hot summer day, depends mostly on my ability to get close to the bird. I think a 900mm scope would just show more heat waves in most cases. (Shooting over snow might be very different, i don't know). Here's a picture of the 80/500 with my Pentax K5 and Sigma 400mm f/5.6... For me, it is very hard to hand-hold this setup, and almost impossible to hold, focus and take a picture at the same time. I think this lens will be on a gimbal and tripod most of the time, and there it excells. Carrying the setup over my shoulder was fine, as long as you pad the tripod legs. I walked about a mile in the sand that way yesterday, no problems.
The focuser is phenomenally accurate, and it needs to be: the DOF is very thin. I think i might have to fit aperture blades somehow. I'm thinking of stripping an old lens to get auto-aperture as well. Minimal focusing distance is 6 meters, and the it's still extremely sharp, right up to the corners.
The plus side is that with the Pentax, the (relatively) fast aperture of f/6.25 allows for Catch-in-focus without any modifications such as butterfly chips. I did pull off a couple of bifs yesterday, but it was not easy.
Bokeh is very nice too, very 3D like, with no color artifacts. It's much smoother than the little sigma.
Contrast, in certain cases like on cloudy days or against the light is not that great. I ordered a UV filter and hope it helps. Of course low contrast is easy to fix on post.
Field curvature is also present, but this only matters for landscape shots focused at infinity. The shorter edges and corners on aps-c format are affected. The long edges are still perfectly sharp.
I also got a barlow lens, but i'm not too impressed.
The ideal extension would be 6cm. I'm using the barlows 5cm extension. The 8mm extender i got is way too long, i get nowhere near infinity with the dslr. Mirrorless cameras will be different, the dslrs flangee depth is about 4.5 cm.
All in all, this is a fantastic setup if your approach is more sedentary, but i don't think i'd pick it for trekking through the jungle... For what i do, i think that's very OK.
So i got myself a telescope. Based on many recommendations (thanks everyboddy!) i decided on TS APO 80/500 super-APO triplet. I should point out at this point that I am allergiv to fringing and longitudinal chromatic aberrations, so i went for the full APO.
When i first opened the package, i was a little in shock... these scopes are BIG! Thanks to everyone who talked me out of a 120/900! Indeed, magnification, especially on a hot summer day, depends mostly on my ability to get close to the bird. I think a 900mm scope would just show more heat waves in most cases. (Shooting over snow might be very different, i don't know). Here's a picture of the 80/500 with my Pentax K5 and Sigma 400mm f/5.6... For me, it is very hard to hand-hold this setup, and almost impossible to hold, focus and take a picture at the same time. I think this lens will be on a gimbal and tripod most of the time, and there it excells. Carrying the setup over my shoulder was fine, as long as you pad the tripod legs. I walked about a mile in the sand that way yesterday, no problems.
The focuser is phenomenally accurate, and it needs to be: the DOF is very thin. I think i might have to fit aperture blades somehow. I'm thinking of stripping an old lens to get auto-aperture as well. Minimal focusing distance is 6 meters, and the it's still extremely sharp, right up to the corners.
The plus side is that with the Pentax, the (relatively) fast aperture of f/6.25 allows for Catch-in-focus without any modifications such as butterfly chips. I did pull off a couple of bifs yesterday, but it was not easy.
Bokeh is very nice too, very 3D like, with no color artifacts. It's much smoother than the little sigma.
Contrast, in certain cases like on cloudy days or against the light is not that great. I ordered a UV filter and hope it helps. Of course low contrast is easy to fix on post.
Field curvature is also present, but this only matters for landscape shots focused at infinity. The shorter edges and corners on aps-c format are affected. The long edges are still perfectly sharp.
I also got a barlow lens, but i'm not too impressed.
The ideal extension would be 6cm. I'm using the barlows 5cm extension. The 8mm extender i got is way too long, i get nowhere near infinity with the dslr. Mirrorless cameras will be different, the dslrs flangee depth is about 4.5 cm.
All in all, this is a fantastic setup if your approach is more sedentary, but i don't think i'd pick it for trekking through the jungle... For what i do, i think that's very OK.
Attachments
Miles Green
Active member
Thank you Cango!
The scope and focuser are already flocked by TS. It's a very nicely finished piece of equipment, I'm impressed. I'll wait for the UV filter to arrive, then see if I need to flock the 5cm extender.
I just did a little test attempting to stop down the lens a bit: I cut a "diaphragm" out of black cardboard, restricting it to about 2.7 cm at the front of the extender (down from about 4.7cm, the internal diameter of the 2'' barrel). The results are very promising as contrast has been boosted significantly, with almost inperceptible loss of light (about 1/3 of a stop i would guess by eyeball). I will report with fewer "abouts" and exact numbers shortly, as i fine-tune the scope's performance. For the time being, i think that a nicer cardboard version will do, those adjustable irises are expensive, especially if all i want is 1/3 of a stop... Resolution is unchanged = tack sharp.
Paul Corfield
Well-known member
The adjustable iris's are ok but they need to be mounted almost inside the scopes body otherwise you get bad vignetting once you stop down too much. Having just one size like you have now is really all you need. If you stop down too much then depth of field also becomes so great that focusing becomes impossible due to things taking so long to go in and out of focus.
The SW980ED comes with a lens cap that has a smaller removable cap which exposes a 50mm hole. This stops the scope down from 80mm and has the same effect as mounting something inside the extender. Contrast and depth of field are improved.
Paul.
The SW980ED comes with a lens cap that has a smaller removable cap which exposes a 50mm hole. This stops the scope down from 80mm and has the same effect as mounting something inside the extender. Contrast and depth of field are improved.
Paul.
Hello Tord,
I am a bit confused here about the dimensions of the SW Evostar (Black Diamond) 80ED.
This is the Scope you have and we are talking about here, right?
http://www.teleskop-spezialisten.de/shop/ED-APO/80-90mm/EVED80OTA-Skywatcher-EVOSTAR-ED80-ED-APO-80-600mm-2-1-10-Au::240.html
Specifications given:
- Tubuslänge (length of tubus)... 62cm
So it's only that missing feature of a retractable hood which makes the scope longer by a full 20cm und thus not quite as portable as for say the Astro Professional 80ED (which is about 45cm, hood retracted, with focuser cap)?
Ouch, could have gone straight to the SW instead of the AP.
Thanks for clearing that one up!
Frank
Miles Green
Active member
Thanks Paul,
I ended up cutting a few different "irises" yesterday. The 2.7mm one did produce some vignetting that I didn't like. I ended up making one with a rectangular opening a little bigger than my aps-c sensor, and inserted it quite close to the camera. Contrast is greatly improved, the speed of the lens (f/6.25) seems unaffected, and it does not vignette at all. That definitely works for me!
Also, i checked the scope again for interior reflections. Though the tube is flocked, the focuser is not. I'll have to fix that!
Thanks for all the helpful advice in this thread, I've read the entirety a few times now, and i keep understanding more every time!
Tord
Well-known member
Hi Frank,
This is a link to the SW80 scope I have and the retailer: http://www.teleskop-express.de/shop/product_info.php/info/p5540_Skywatcher-EVOSTAR-ED80-ED-APO-80-600mm-2--FOC-MICRO.html
I am not sure what they exactly mean with "tube length". The figures I posted were as a reply to Jules who wondered about how big rucksack was needed to transport the scope (with lens hood off, focuser retracted, extension tube unmounted).
You could shorten the lens hood. But it weighs almost nothing and offers a good protection and also strongly mitigates dew formation. But yes, it adds length...
/Tord
Tord
Well-known member
Hi Miles,
Welcome to the club. I am curious about the quality you will get from a true APO. The picture of the Gull looks great. Keep the pictures coming!
/Tord
Tord,
this is the same scope. It seems obvious that by tube length of 62cm the lens hood is included, which is basically, as you conveniently mentioned, detachable to be fitted into a smaller rucksack.
This option didn't come to my mind when in deciding which scope to go for. As transportability was a priority I went for the Astro Pro.
But as obsolescence goes.. the AP got hit by a rock recently and I just ordered a SW80ED (and that was before, when I thought the hood could be retracted) :-O
I see your mount is shortened. Do you just flip the hood over then? Or at least could you?
http://www.e-group.uk.net/gallery/data/1243/IMG_4739_DxO.jpg
Miles Green
Active member
Thanks Tord,
The IQ is phenomenal, i have not seen any traces of chromatic aberration. With this scope, there's nothing, not even with test shots, shooting leaves against the sun. I don't correct for it, there's nothing to fix. What botheres me with my Sigma "apo" other than the fringing, was that i was getting purple water in front of the bird, and yellow water behind it. That was very hard for me to fix.
It's getting really hot here so the IQ bottleneck is either atmospheric turbulence or early morning / late evening high ISOs, or the contrast thing which seems fixed with the cardboard mask (but that's not really a scope problem, it has to do with the camera adaptor). With the gull, adjusting the contrast brought out a lot of noise, and focus was a few mm off: the gull let me get really close, it's barely cropped. I shot at ISO 500. I'll post a good bird close-up when i get one!
