Fish eye lenses for astroimaging

[MartinB]

Is anyone using fish eye lenses for wide field night sky shots. I'm looking at ultrawide angle EPs and wonder whether (esp Tokina 11-16mm F2.8) but just wondering whether a perspective benders might be worth considering.

[John]

This is a rather "off the wall" response I'm afraid but I recall reading an article in "Astronomy" magazine many years ago about what they called "Hubcap Astrophotography". The basic idea is that you get a nice old chrome domed hubcap (like those that used to be fitted to the old US cars I guess) drill it in the centre, fix an upright support so that a camera can be positioned pointing down onto the reflected image of the sky in the hubcap (which has it's convex side uppermost). The results, if things come together, can be 360 degree panoramas of the night sky I believe.

Sounds a bit wacky but the results can be interesting !.

[Merlin66]

I still have the Zuiko 28mm from the ol' days. Used to give great wide angle shots on the OM1.

There must be plenty of those old fisheye lens available s/h....

EDIT: google "all sky cameras" - the VW hubcap is included!

[Psychobilly]

I use a 10-20 which when used on an APS-C sized sensor is 15-30 EFL on the Nikon (1.5x) and 16-32 EFL on the Canon (1.6x) even at these FL its already a perspective bender... any tilt at all witll introduce distortions although these can be corrected in CS...

One thing you wont have to worry too much about is focus as the DOF is enormous with these even fairly wide open..

Peter...

[JonH]

I don't know if you're a Canon user or not, but there's a 15mm f2.8 full frame fisheye. It's not a L series but is sharp as a tack.

[themos]

Peleng - 8-mm fisheye

[MartinB]

Thanks guys. Looks like a fish eye is a goer then. Thanks for the link Themos, really interesting. I presume you can do the same sort of adjustments in PS that are demonstrated here in IRIS.

[Ant]

The only thing that worries me about the fish eye lenses, as I would LOVE one, is dew.

Even on the standard canon lens (the one that came with the 300D) I have to use a heated dew strap - but I doubt that option would be any good for the fish eye.

Are there ways around the dew issue?

Cheers

Ant

[callump]

I have the 8mm Pelang lens, but I have only had it out for astro use once, mostly due to the poor weather. Though it is quite fun to use in the day-time too.

But too early to judge it really for night time.

/callump

[MartinB]

The only thing that worries me about the fish eye lenses, as I would LOVE one, is dew.

Even on the standard canon lens (the one that came with the 300D) I have to use a heated dew strap - but I doubt that option would be any good for the fish eye.

Are there ways around the dew issue?

Cheers

Ant

Theres a lot of unprotected glass sticking out. If I get one I'll try Billy's suggestion of heated hand warmers.

I'll be interested to hear how you get on with the Pelang Callump

[Psychobilly]

You could also consider adding a fish eye adaptor to an existing lens... as an intro into ultra wide angle..

I think SteveL has been down that route... sold them a while back.. there were other threads with some shots using them...

http://stargazerslounge.com/completed/91789-0-45x-dslr-wide-angle-adapters-sold.html

Peter...

[SteveL]

The screw in fish eye adapters do give a lot of distortion and colour fringing at the edges, but show some HUGE areas of sky

[MartinB]

Thanks Steve, someone got a good buy for £10!

I've been having a look at the TWAN site and a lot of images seem to have been taken with a fish eye and then the image has been converted to a panoramic view. I didn't understand this until I looked at Themos' link above. The important thing seems to be to get one that gives a true 180 degrees then you can give the lens a good warm up, point at the zenith, run off a 45 second exposure and then turn it into a panorama in PS.

Off to google Pelangs

[MartinB]

Well I've just bought a Peleng 8m fisheye for £138 on fleabay. Hope to post some results soon.

[iksose7]

Well I've just bought a Peleng 8m fisheye for £138 on fleabay. Hope to post some results soon.

I know its been a while Martin but any chance you have those results lying around? I'm trying to find a decent fish-eye at the moment. How did the Peleng do?

[robbieince]

I have just got a samyang 8mm f3.5 for my eos 500d, tried it out for the first Astro time at Galloway sp and was very pleased with the results. I will post them in another thread soon.

I reckon it's a 120 degree FOV when on the 500d so you do get distortion a but no full vignetting.

Regards

Rob

[Photosbykev]

The Samyang 8mm f3.5 has a horizontal FoV of approx 165 degrees on a Canon crop sensor. I used one recently for the Leonids and I quite like the perspective it gives. Also it is quite happy with a dew strap just around the lens hood which kept the lens clear all through the night

[robbieince]

Wow that's a tad more than I thought. I used a dew strap on it whilst at Galloway and had no dew problems. I did stop it down 2 steps to improve the edge stars though.

Regards

Rob

[sologuitarist61]

The Samyang 8mm is a great piece of kit, beautifully and soldily made and takes good images. Cost about a 1/4 of an equivalent Canon or Nikon fish eye

[Photosbykev]

The Samyang 8mm is a great piece of kit, beautifully and soldily made and takes good images. Cost about a 1/4 of an equivalent Canon or Nikon fish eye

but the Canon and Nikon are better, especially controlling CA and corner sharpness, whether they are 4 times better is up for debate

[MartinB]

I know its been a while Martin but any chance you have those results lying around? I'm trying to find a decent fish-eye at the moment. How did the Peleng do?

I've used it occassionally and will dig around the hard drive and upload some results. SteveL has it on loan at the mo and has posted a couple of shots. I think it is a very handy lens. There is a fair bit of distortion around the edges but you get a massive view of the sky and has great potential for big milky way type shots. It is completely manual which is fine for asto but might be a bit of a pain for day time use.

[iksose7]

I've used it occassionally and will dig around the hard drive and upload some results. SteveL has it on loan at the mo and has posted a couple of shots. I think it is a very handy lens. There is a fair bit of distortion around the edges but you get a massive view of the sky and has great potential for big milky way type shots. It is completely manual which is fine for asto but might be a bit of a pain for day time use.

Thanks, that would be great. Will have to see if i can find Steves shots aswell. The manual aspect is no bother, i dont think i would really use it for daylight photography.

[alan potts]

I know someone who has 2 of the very old Nikon 8mm ( I think ) fisheye lens boxed and unused. They are worth a lot of money.

I used to have a 14mm Canon lens which gave a massive FOV but never tried it on the sky. I would think using a fisheye your guiding need not be perfect, if you do some post the results, it would be interesting to see them.

Alan.

[MartinB]

Here are a few Peleng images. Sorry, I can't remember any of the details other than taken using a Canon 1000D

The first is taken from my back garden, the visible constellations gives an idea of the FOV using an APS chip.

The second is a Milky Way shot from the Greek island of Kastos. The odd lighting effects come from a little bar and shows the tendancy of the lens to show flares (inherent in the design). Also the stars stay reasonably tight quite well out towards the edges of the field.

The 3rd is a simple star trails image from an SGL star party. It is a dew magnet but a dew strap does the job but here it's slipped too far forward.

The 4th is a day time shot from the same star party and has had a bit of gentle manipulation using a programme called Rectfish. This will take out the fish eye bending and can be used more aggressively than here but at the expense of some extra distortion which then needs cropping out. The last shot is the original.

I think it is a handy lens to have, potentially great for big milky way type shots but also for odd perspectives e.g. looking up through trees.

[alan potts]

Some very nice and interesting results. This is not a fisheye as such, but I guess you know that. With a real 180 degree lens you have to be careful not to get your feet in the shot. But they are nice just the same. Though I have 3 very large and costly telephotos there is something really different about ultra wide angle shooting, for sure you rarely know what you are going to get.

Alan.