77 replies to this topic

[StephenFrink]

I forgot to show the results of the 16-35 II with the fisheye port. Clearly, the superdome was better, but the best I could do with the fisheye port was with the PVL50.





I haven't found a particular Canon lens that is well suited for the fisheye port yet, but it is very good for the lens it was designed for, the Nikkor 16 (and now the 10.5). It is curious that while both the Canon and Nikkor fisheyes are nearly the same angle of coverage, they don't perform identically in the same port.

For Canon I prefer the superdome for 15mm and 16-35mm II/17-40.
For Nikon either fisheye port or superdome will work with both 16mm and 10.5mm.

[hoovermd]

The entrance pupil is likely to be 5~10mm further away from the camera body as James says. ...

Well, I just purchased mine and set up the jig to calculate the entrance pupil.

Does this number look reasonable to anyone else who has played with the lens?

[StephenFrink]

Ok, now I've finally had a chance to do real world testing on the 16-35 II lens on a Canon EOS1DsMKII full frame camera in Seacam housing, and real world tests refute my original pool tests.

I couldn't decide whether PVL 55 or PVL 60 was the best results in the pool, so I had a custom port extension made at 57.5mm. Tests with that port extension and superdome were less than stellar. It did better with subjects along a flat plane, but I tried to choose set-ups that really challenged corner performance. This is about as tough as it gets, with the fish in the right corner wrapping around me, and the focus point in the center of the frame.




I tried the PVL 57.5 with the wide port and that didn't work well either. Very soft in the corners.

[StephenFrink]

I tried PVL 40 and PVL45 as well over subsequent shoot days, but in the end the best I could do was the superdome and PVL35. Not perfect, actually not much better than I was able to do with my old 17-40mm Canon zoom.



16-35II @ 16mm


16-35II @ 35mm

The lens has more contrast (sometimes good, sometimes bad, depending on your subject and lighting) and is sharper and absent the vignetting the 17-40 sometimes reveals.

But, if your criteria is substantially improved corner performance relative to the less expensive 17-40mm zoom behind a dome port, I am not able to document it.

BTW ... to really complete the test I'd like to try it with a diopter, probably a +2. But, I can't find an 82mm diopter from a quality filter manufacturer either by means of Google search or at B&H. Anyone know who might make good glass in the 82mm thread?

[meister]

Thank you much for sharing your results here on the board!

[davesea]

I am using the Canon 16-35mm II lens with a Canon 5D and Aquatica housing. My previous SLR set up was an F3 in Aquatica. So I have gone from total manual to total auto. I am currently not using strobes and freediving with the 5D and 16-35mm. This is my only lens I plan to use underwater. I am also using a green water magic filter so I have lots of light limitations.

Here are a couple galleries with photos from this set up.
http://www.underseai...p;id=1187911789
http://www.underseai...p;id=1187199886

Dave
www.underseaimages.com

[craig]

Heliopan 82mm diopters from B&H

[photomrw]

Hi all,

I went ahead a got the new 16-35II and after a recent assignment, I'm still not satisfied with the soft edges. However, I will say that I like it much better than the 17-40 for my topside work.
Michele Westmorland

[StephenFrink]

Heliopan 82mm diopters from B&H

Thanks for the link Craig. I ordered from B&H immediately, but they are special order items and may take a couple of weeks to ship. Once acquired, I will test the +2 with Seacam superdome, wide port, and fisheye port. Nothing else in terms of port diameter or port extension has really delivered stellar resolution in the corners so far. I am hopeful the diopter will help.

[Craig Ruaux]

Stephen, how about SinghRay for a custom diopter. There main business seems to be neutral density grads, but they may have the wherewithal to do a diopter, and at least they are relatively local to you.

[StephenFrink]

Stephen, how about SinghRay for a custom diopter. There main business seems to be neutral density grads, but they may have the wherewithal to do a diopter, and at least they are relatively local to you.

Thanks for the thought Craig, but I have the Heliopan on order. It should show up within a couple of weeks so I can complete my testing. Meanwhile the 16-35II is certainly usable without a diopter. Very sharp in the 20-35mm zoom range and actually probably not a lot different in the corners than the 17-40 Canon, or Nikkor 12-24 for that matter. But definitely not perfect. Here's a shot I took last weekend. The lens does reasonably well on subjects on the same plane. (Seacam superdome, PVL35, F-6.3)



The challenge is with a center focus point somewhat in the distance and dimensional subjects in the foreground that reveal the soft corners. That's the aberration I hope to be able to correct.

Also, I've ordered a manual focus gear for this lens. I think there is a sweet spot between a subject in the distance one might choose for AF, and a focal point that might hold both foreground and primary subject. Rather than constantly shifting zones of AF, I think I'll go back to CF 4-1 on Canon and MF as needed.

[Drew]

Stephen,
Another diopter choice if there is no size constraint is the Century Optics 86mm +2.6 or +2. Being achromatic multi-element does lower CA and distortion, but it's thick.
You'll need a stepup ring and Cokin makes a really thin one.

[StephenFrink]

Thanks for the link Craig. I ordered from B&H immediately, but they are special order items and may take a couple of weeks to ship. Once acquired, I will test the +2 with Seacam superdome, wide port, and fisheye port. Nothing else in terms of port diameter or port extension has really delivered stellar resolution in the corners so far. I am hopeful the diopter will help.

I see it has now been 6 weeks since I ordered the 82mm Heliopan from B&H and it still has not arrived. Anyway, I was at our annual Shark Shootout at Stuart Cove's last week and started the week shooting the 16-35mmII on the 1DsMKII with a PVL35 and Seacam Superdome, but the corners were still not to my satisfaction. So, I revisited the custom PVL 57.5 (millimeters) that I asked Seacam to make a while back. Actually, it was not too bad ... certainly better than the PVL35.

Testing this lens remains a work in progress. I still don't have the 82mm diopter to try out, but I am certain that the PVL57.5 is working better than the PVL35. Probably about the time I get this one figured out Canon will start delivering the new 14mm and I can start all over again with that.

Here's a shot with the 16-35II and PVL57.5, part of a product shoot I was doing at the time as well.

[hoovermd]

I see it has now been 6 weeks since I ordered the 82mm Heliopan from B&H and it still has not arrived.

so sorry to hear. Mine took about the same time from my local camera shop. I ordered the "slim" version over 3 months ago (right after the lens came available).
Seems that Heliopan is backordered a bit

I'm headed to Galapagos next week with the lens and the new port extensions for my UK-Germany dome.

Hope to have decent luck there with this lens as I'm dissatisfied with the 14mm at this point.

Edited by hoovermd, 15 October 2007 - 02:47 PM.

[Dan Schwartz]

Stephen,

Thank You for posting the test results... I've learned a lot.

Ok, now I've finally had a chance to do real world testing on the 16-35 II lens on a Canon EOS1DsMKII full frame camera in Seacam housing, and real world tests refute my original pool tests.

I couldn't decide whether PVL 55 or PVL 60 was the best results in the pool, so I had a custom port extension made at 57.5mm. Tests with that port extension and superdome were less than stellar. It did better with subjects along a flat plane, but I tried to choose set-ups that really challenged corner performance. This is about as tough as it gets, with the fish in the right corner wrapping around me, and the focus point in the center of the frame.

I tried the PVL 57.5 with the wide port and that didn't work well either. Very soft in the corners.

[StephenFrink]

Heliopan 82mm diopters from B&H

Waited 2 months for the Heliopan to arrive, but when it finally did, it vignetted badly with 16-35II @ 16mm. I remember being offered two versions, and ordered the slim version, but received regular. Sheesh ... Guess I won't be experimenting with 82mm diopter at Great Detached Reef next month.

[MaLe]

Hello 16-35 user's

I wonder if anybody has a update ti the experience with this lens in combination with diopters?

Finlay traded my version (I) as well and the new (II) is clearly more sharp at 16mm.

Regards,
Matthias

[don2008]

The way the required dopter is calculated is from a simple little formula:

P = 1000/4R where P is the diopter required (usually +1, +2, +3, or +4) and R is the radius of the dome being used (in mm)

Very informative - thank you Paul (Q...
Can you perhaps pls. help throw some more light on the physics here: where have you come upon that specific formula - as well as possible in-depth describtion of the issue regarding virtual image ("The distance of this virtual image of an underwater subject at infinity from the front of the dome is 3 x the radius of the dome (3R)").
Any info here will be great - Thanks!
/S

Edited by don2008, 03 February 2008 - 08:38 AM.