Nauticam Fisheye Conversion Port shipping Mid January

[DreiFish]

2 hours ago, ChrisH said:

I don't know about the 2x TC, but Seacam has a dedicated zoom gear for the 1.4x TC from Kenko with the fisheye lenses. That is what I use if I do need more flexibility.

But the TC also introduces a hit in the image quality: it tends to work not as good when shooting against the sun and will introduce more flare. Other than that, I find the image quality to be fine for me. 

I just got my Kenko TELEPLUS HD pro 2x DGX Teleconverter for Canon EF, along with the 40mm port extension for Nauticam.  if I can source (or manufacture) a zoom gear, I look forward to testing the image quality, zoom range and autofocus performance next time I get a chance to dive. 

 

In the meantime, I did some field of view comparison with rectilinear lenses on land that I'll be posting in a different thread shortly.

Edited June 19 by DreiFish

[Chris Ross]

9 hours ago, ChipBPhoto said:

 

I personally prefer to have a sharper subject with a softer background for separation in my CFWA.  For me, versatility tends to be a top priority which could make the FCP a solid overall choice for the type of images I like to create.  While I do not have the talent of Alex, the images he shared do show the quality the lens is capable of producing in a variety of settings.

 

 

 

The example image I was referring to IMO had un-workably thin DOF.  I don't know how extreme the magnification was on that shot but for me you would have to be picky about subjects the soft coral head had background and foreground out of focus and to me blurry foreground elements ruin a shot, background elements being soft is not an issue for me.  The shot was taken at f13 so not much opportunity to get more DOF by stopping down either.

[RomiK]

I've touched on that earlier in this thread - FCP is not a fish eye lens. It's a fish eye distortion element put in front of a rectilinear lens. So the DOF is going to be lower than the pure fisheye. So as such it will offer blend of subject pulling like fish eye lens coupled with subject isolation of rectilinear solution. So I'd say it's just a tool for some - subject oriented - type of imagery which like @Alex_Mustard prefers (who I guess was somewhat involved in its development) but it's not a tool for other type of imagery. Off course one can only debate it's usefulness  and versatility for private arsenal of tools given its cost and mass concerns but for rental circuits - should there be some 🙂 - might be great... And it seems to be excellent tool for it's purpose nevertheless 👏

[Sergio]

On 6/16/2024 at 4:04 AM, Chris Ross said:

For those who don't want to download the zip file here is a centre crop, quite sharp where it's in focus.

 

1/100 @ f13 ISO100 and 29.5mm

 

So quite shallow depth of field from being in so close - do you recall the approximate size of this soft coral?

 

Sorry, I only respond now. This is a very interesting discussion; having all those varied viewpoints will certainly help make decisions to get one or not.

Regarding the distance I took this shot: it was very close. It's probably about 5 cm distance and that little bit of soft coral which is sticking out is even closer.

 

I am really not a photo pro, so I am probably saying something completely wrong here, but still will try to formulate my understanding here:

From what I understand DOF depends of course on the focal length but also the camera sensor and the distance of the subject.

I went to https://www.photopills.com/calculators/dof and plugged in some information, knowing that it's not all the correct but will probably give some indication of the DOF when being so close at the subject:

 

 

So this would be a very shallow DOF of give or take 3cm.

 

when adding a 2x Teleconverter DOF goes down to just about 1 cm:

 

 

Now, I understand that fisheye lenses work a little bit differently from what I read and I couldn't really find any information about how to calculate DOF for a fisheye. So I am not sure that the rules above really apply to a fisheye but most images that I have seen which were CFWA typically have some blurriness in the background and would probably have it in the foreground as well if something were to stick out such as in that image I took. 

Hoping some of you who know about this stuff much better than me, can correct or support my understanding.

 

 

[Sergio]

On 6/15/2024 at 5:44 PM, DreiFish said:

 

Excellent resource, @Alex_Mustard. A critical examination of the images (pixel-peeping, I mean 😄) does seem to support the conclusion that (a) the foreground sharpness (or maybe it's micro-contrast?) is not on the same level as a native fisheye and (b) the zone of acceptable focus is narrower, rendering more blurred out backgrounds. 

 

For example, look at the surface water in this shot (upper left corner) in this shot - linked, not copied! (F11, 32mm) The fish school is in focus, but the background is very blurred. Granted, the slight zoom and 1/30 shutter speed might contribute to that.

 

Or this shot (F13, 22mm, 1/60s). 

 

Or this shot. 

 

 

 

Another shot to showcase foreground sharpness and background (F13, 30mm, 1/200s). 

 

Compare this with a somewhat similar photo I've taken with the GH5 and Canon 8-15mm. Personally, I don't really see a image quality improvement you'd expect to see with a native fisheye on full frame.

 

Or this shot from Alex 

 

With a couple taken with the Canon R5C, 8-15mm fisheye at 15mm, F8

 

 

What were your subjective observations on this topic, @Alex_Mustard?

I wanted to give my 2 cents to this topic as well;-)

I think the very first photo where you point out the blurriness of the top left corner is due to motion blur. I have been watching a lot of videos of @Alex_Mustard and also subscribed to his online courses and he does enjoy taking shots panning the camera to instill motion in his images. Look at the background behind the school of fish and you see how it all "smears" away. So I think the background is blurry by choice.

 

Also, from everything I heard  @Alex_Mustard claim on his videos was not that the FCP would provide equal image quality to the WACP-1/2 but rather versatility in reach for a fisheye or fisheye-like lense. He compared the reach to the Tokina 10-17 which is still used a lot for APSC cameras but has less reach than the FCP-1. I think he also commented that the image quality of the FCP-1 should be equal to or maybe better than a fisheye including a teleconverter. And I suppose this is maybe what we ought to compare the FCP-1 with? 

It would be nice to have a better understanding of the reach of a fisheye with a teleconverter vs the FCP-1 and image quality at each focal length for the same aperture, iso, lighting etc. 

 

[Chris Ross]

6 hours ago, Sergio said:

Sorry, I only respond now. This is a very interesting discussion; having all those varied viewpoints will certainly help make decisions to get one or not.

Regarding the distance I took this shot: it was very close. It's probably about 5 cm distance and that little bit of soft coral which is sticking out is even closer.

 

I am really not a photo pro, so I am probably saying something completely wrong here, but still will try to formulate my understanding here:

From what I understand DOF depends of course on the focal length but also the camera sensor and the distance of the subject.

I went to https://www.photopills.com/calculators/dof and plugged in some information, knowing that it's not all the correct but will probably give some indication of the DOF when being so close at the subject:

 

 

So this would be a very shallow DOF of give or take 3cm.

 

when adding a 2x Teleconverter DOF goes down to just about 1 cm:

 

 

Now, I understand that fisheye lenses work a little bit differently from what I read and I couldn't really find any information about how to calculate DOF for a fisheye. So I am not sure that the rules above really apply to a fisheye but most images that I have seen which were CFWA typically have some blurriness in the background and would probably have it in the foreground as well if something were to stick out such as in that image I took. 

Hoping some of you who know about this stuff much better than me, can correct or support my understanding.

 

 

Hi Sergio, according to your exif data the soft coral was taken at about 29mm focal length and this is about equal to the field of view (horizontal) of an 11.5mm   rectilinear  lens based on some calculations.   If you look at it being a fisheye lens that would be an 18mm fisheye in round numbers assuming that a 15mm provides a 180 deg diagonal field.  11.5mm would be the number I would suggest using in the DOF calculator.  The depth of field of a fisheye in a dome of the same focal length would be a bit more than what is calculated here.  I also can't find any references to Fisheye DOF calcs.

 

The subject distance should also be from the sensor so that would be 16mm plus lens length plus distance from lens to subject .  So that would 16mm plus your 50mm plus length of your lens.  It's hard to work out what would be with 24-50mm combined with the FCP optics but would be at least 16+ 50 + 50 = 116mm , The dome looks about 120-140mm dia so add 60mm radius maybe try it with 176mm distance.

 

This brings the DOF up to 20cm.