de fish eyeing

hi there
a quick question

i have been considering getting the canon 8-15 FE
and then i understood that there is a way to de-fisheye.

will the quality of the capture at 8mm at f4 on a FF
be of excellent quality after de-fisheyeing (for the lack of a better term)

In other words - will the picture take a hit on IQ with the processing?
Is the processing difficult?

thanks so much

I don't know about the 8-15 FE, i have the 15mm f/2.8 USM

1) to "de-fish" it's very easy with LR5, go to "Lens Corrections" on the tab "Basic" > enable profile corrections and it's automatic and instantaneous, or you go on the tab "manual" and you play with the sliders

2) de-fishing affecting the picture ? YES ! it does, specially all around the center to the corners !

3) it's a learning curve to use your fisheyes without defishing after, pratices and tests will slowly (or quickly) help you to learn how to use it, where to place the straight line, or just half de-fish in PP

i have a pure example of what not to do with the straight lines or what happen with those straight line
which will tell you too what happen after a defish

Before

After defishing in LR5

ceriltheblade wrote in post #17438975
will the quality of the capture at 8mm at f4 on a FF
be of excellent quality after de-fisheyeing (for the lack of a better term)

8mm on a FF is a circle (see http://www.northlight-images.co.uk …/lenses/sensor-sizes.gif), and I'm not sure how well the defishing process would work.

I use a 8mm fisheye on a crop camera, which doesn't require any cropping of the image. Over at Lonely Speck there's a pretty good defishing tutorial:

http://www.lonelyspeck​.com/defish/

LR doesn't defish particularly well, there's a plugin for PS called Fisheye-Hemi which does a great job!

resevoir dog - thanks for answering.

help me out here. except for losing an amount of your angle of view, what is the "DONT" that you note in your example? Those lines in your after photo look pretty darned straight to me! Sorry. I guess I am being dense.

are there other options in regards to defishing? Does one type of defishing fit one type of subject vs another?

thanks for that.

have you used the fisheye hemi?
Have you found it to be superior?
Have you found there to be a loss of IQ when using it?

I suppose I would be interested sometime in the future to find out if there was any difference between a defished 11mm f4 of the 8-15 vs the new rectilinear 11-24 f4 which is scheduled to come out.

granted - it is more curiosity than a factor in decision making.... 1.) $3k is too steep for me 2.) I really am interested sometimes in the distortion of the FE

I've tried the trial version (it water marks the hell out of the image, but it gives you a good indication of what it does). I really liked it, will purchase it at some point. If you notice Reservior Dog's defished photo, the trees are stretched out and the overall image has been cropped considerably. The advantage of Hemi, especially if you use it like it has been in that tutorial, you retain more of the image and don't lose so much detail. LR is trying to convert the image in a rectilinear way, which isn't the aim of a fisheye.

It's hard to make a comparison between the two, a fisheye will always have a larger field over view at the same focal length as a normal lens (see again that Lonely Speck link). I think a fisheye prime is the way to go!

danialsturge wrote in post #17439074
I've tried the trial version (it water marks the hell out of the image, but it gives you a good indication of what it does). I really liked it, will purchase it at some point. If you notice Reservior Dog's defished photo, the trees are stretched out and the overall image has been cropped considerably. The advantage of Hemi, especially if you use it like it has been in that tutorial, you retain more of the image and don't lose so much detail. LR is trying to convert the image in a rectilinear way, which isn't the aim of a fisheye.

It's hard to make a comparison between the two, a fisheye will always have a larger field over view at the same focal length as a normal lens (see again that Lonely Speck link). I think a fisheye prime is the way to go!

I will look again at the link you gave. I ran into the article through google, but wanted to get some third party disinterested views here.

bold/underline above - why would you choose a FE prime over the 8-15 (besides the cost difference)

ceriltheblade wrote in post #17439085
why would you choose a FE prime over the 8-15 (besides the cost difference)

Mostly the price difference to be honest, but on a FF I personally don't like the requirement to have a to crop the black boarders out - unless that's what you're after of course. I also use my fisheye for astrophotography, or at least that's why I bought it, so the extra stop that the primes offer is an advantage. I believe the Rokion/Samyang fisheyes offer slightly different fisheye perspective, with the former looking less 'fishy' (see: https://photography-on-the.net …showthread.php?​p=17314170).

When I use LR5.7 to de-fish my Σ15mmFE, I am generally pleased with the result. I think that defeats the purpose of FE, though. I want the distortion; that is why I bought the lens. So I am obviously not as picky.

I agree with the poster above who stated that de-fished FE will always be wider than the same FL rectilinear lens. My 15FE, even defished with LR, is wider than my Rokinon 14.

ceriltheblade wrote in post #17439048
resevoir dog - thanks for answering.

help me out here. except for losing an amount of your angle of view, what is the "DONT" that you note in your example? Those lines in your after photo look pretty darned straight to me! Sorry. I guess I am being dense.

I bought the FE for underwater photography (look at my gallery, most underwater pictures are made with a FE non defished)
it's only after that i bring the FE on the land, where slowly, i learned to keep straight line without defishing (i am a slow guy )
i put some sample here https://photography-on-the.net …showthread.php?​p=17355346 where you can see the pyramid without being defished (that's why the note "what not to do" to keep straight lines )

About software i should agree with everyone, because i don't defish a lot, i became lazy and use LR when i want to, but before, long time before i was using PTLens, which do a better job than LR and by far

The EF 15mm f/2.8 USM, it's an excellent lens, but the body seems quite fragile (i always manipulate it with care), it is not any more in production so if you want to go prime i recommend the sigma (a friend have it, it produce nice pictures too)
I will not go with the 8-15mm i do not need it at all because 15mm FE it's already a diagonal of 180º and the f/2.8 it's useful in diving when it's quite dark without flash or even for astro as mentioned above.

IMO Yes, some pictures you will defish it less, some more, some not, etc ...,
In fact after some use, you will see it thru the viewfinder what you can do or not to defish later or not, and you will move/orient the camera differently, or move yourself, or both depending on what you see in the viewfinder

Here is a comparison I made showing Fisheye Hemi, and Photoshop adaptive wide angle filter differences for how much you lose using each method: http://www.fredmiranda​.com …2428/0?keyword=​x#12804989

Nobody at FM made a single comment-maybe my little demo can help you

the fred and miranda examples are very interesting for sure. thanks. i have to agree with some of the posters there that the deformations introduced both by the lens and the subsequent defishing are pretty significant on subjects like people.

for those of you who use it for astrophotography, is the deformation as significant?

as an aside, how many gel filters can fit in the holder at the rear of the lens? do they get destroyed easily?

It's harder to get the framing right with fisheye, but done properly and I think the results can be great.

I've yet to have a chance at astrophotography, but a reason I got one for that purpose was because of FuzzSummit's work (for example: https://www.flickr.com …45/in/faves-danialsturge/). It's great for Milky Way shots as you can get pretty much the whole arch in a single photo, and the curve lends itself nicely - and if you have the horizon in the centre of the shot then there's no desfibshing required!

I can't speak for the gel filters as I have no experience of those.

yeah. I use fisheye for 180-degree FOV and distortion. don't grok the defishing at all.