OM-D EM-5 Nauticam with 9-18 zuiko?

[oskar 6]

I am about to buy a EM-5 kit with the 8mm fisheye and 4.33" dome.

 

I have been offered to also buy the 9-18mm compact WA zoom, zoom gear and two 20mm extension rings, The extension rings is supposed to make the 4.33" port work equally well as the dedicated port for the 9-18.

 

I originally intended to eventually get the 12mm f2 for use under the same dome as the fisheye for moderate WA.

 

 

1. What is the current experience of the 9-18 mm WA? I have been surfing the treads, but not found much current comments on it. There seems to be a preference for the 7-14 Panasonic in this case, in the early comments. Anyone here using it now and what are your views? (Please link if already commented in another thread.)

 

2. Is the option with two extension rings on the 4.33" dome as good as the dedicated dome/port for this lens?

 

3. Should I hold off and get the 12mm as planned? (this is a matter of personal opinion I know, but anyway)?

 

Cheers

/O

[nudibranco 26]

I personally love the 8mm both with the 3.5" and the 4.33" dome. The 3.5" allows to get very close and it is VERY compact. The 9-18mm is a mixed bag. I tried it with the 3.5" and a 30mm extension but did not resolve the corners correctly and I did not try it with the 4.33" ( I did not have it). I originally used it with its 4" port but found that could not focus as close as I wanted at times and frankly (this is my subjective take underwater) I prefer fisheyes to rectilinear WA lenses. I would use it if I could get closer by some diopters but have not experimented with it. I just end up using either the 8mm (super sharp!) and macro lenses most of times!!!

[blibecap 29]

The 9-18 lens would need the dome 4mm further away from the camera as compared to the 8mm fishe eye. What 3.5" dome are you talking about?

[oskar 6]

Thanks, are you reffereing to my option there with the 9-18 behind the 4.33" dome and two 20mm extensions? That it needs to move out another 4mm to get sharp?

 

 

The 9-18 lens would need the dome 4mm further away from the camera as compared to the 8mm fishe eye. What 3.5" dome are you talking about?

 

Thanks!

/O

[oskar 6]

No experiences with the 9-18 with the below combination?

 

How about the 7-14, is it possible to use it behind the 4.33 dome and some combination of extensions?

 

Cheers

/O

Thanks, are you referring to my option there with the 9-18 behind the 4.33" dome and two 20mm extensions? That it needs to move out another 4mm to get sharp?

 

 

 

Thanks!

/O

[oskar 6]

About using the 9-18 behind different domes as I still have this offer on the table:

 

How is the 9-18 corner sharepness and close focus limit behind the recommended 4" port?

 

Are the 4.33" dome and the 4" dome port same radius but different width? Are the information of the Nauticam ports available somewhere? The Nauticam site is quite breif in that matter

 

 

Cheers

O

 

 

 

 

The 9-18mm is a mixed bag. I tried it with the 3.5" and a 30mm extension but did not resolve the corners correctly and I did not try it with the 4.33" ( I did not have it). I originally used it with its 4" port but found that could not focus as close as I wanted at times and frankly (this is my subjective take underwater) I prefer fisheyes to rectilinear WA lenses. I would use it if I could get closer by some diopters but have not experimented with it. I just end up using either the 8mm (super sharp!) and macro lenses most of times!!!

[Phil Rudin 428]

The Nauticam port charts are a downloadable PDF. All you need do is go to Nauticamusa.com and on the front page right side you will see port charts. download the PDF and scroll down to the M43 page. If the port combination is not on the chart then it will give less than adequate performance as in the case of a 7-14 behind the 4.33 port with stacked extensions.

[oskar 6]

I should probably clarify the reason that I am asking this.

 

I have been offered to buy the 9-18 + 2 20mm extension rings to be used with the 4.33" dome. The seller is also an agent for Nauticam and claims that Nauticam has confimed that this combination works well.

 

However, as Nauticam does not officially support this I would like to hear second opinions to this combination.

 

Just looking at pictures it also seems to me that the radius i different for the 4.33" dome and the 4" port. If this is right it seems less plausible that the above combination would be good.

 

Cheers

/O

[Storker 13]

How is the 9-18 corner sharepness and close focus limit behind the recommended 4" port?

 

Corner sharpness is so-so, except at rather small apertures. I guess the focus plane curvature is a little too much for the lens to handle. I'd rather not stop up above f/8, and I prefer to shoot at f/11 or smaller. That's a bit of a challenge in our waters if you want to balance flash and ambient, since it's usually rather dark at depth here, especially in the autumn, winter and spring. Close focus is half-decent for me and my demands, but it's limiting me a little bit if I try to shoot CFWA. I'm considering a fisheye for that, but I don't have the €€€ right now.

 

This picture is taken at f/8. I've cropped bottom and left, but look in the top right corner (click for larger size).

 

This one is also at f/8, cropped bottom and right. Top left corner uncropped.

 

Corner sharpness improves a bit when you step down further, though. This one is at f/11, cropped to 3:2 format.

 

[blibecap 29]

Poor corner sharpness is not a result of the dome curvature but rather the dome is in a incorrect position related to the nodal point of the lens. In other words the dome is either too close or too far away from the camera body. You can find more information here http://www.creativeillusionsphoto.com/virtual.htm

[Phil Rudin 428]

This lens when zoomed between 9 and 18mm moves in and out more than an inch so in effect the nodal point changes depending on what AOV you are using.

 

With the 7-14 zoom this is not as much of a problem because the lens moves very little. The new 12-40 zoom has an even longer zoom range.

[blibecap 29]

I agree that with zoom lenses the nodal point usually moves. However the nodal point movement is not necessarily related to the throw (expansion or compression of the lens length when zoomed) of the lens. If you place the dome in the correct position usually for the wide angle it will be off position every where else however, this is the best you can do.

[Storker 13]

Poor corner sharpness is not a result of the dome curvature but rather the dome is in a incorrect position related to the nodal point of the lens. In other words the dome is either too close or too far away from the camera body. You can find more information here http://www.creativeillusionsphoto.com/virtual.htm

 

Thanks for the info. However, I'd like to mention (just FTR), that I was referring to focus plane curvature (curvature of field), not dome curvature. AFAIK, that's always an issue when using dome ports and close focus distances, no matter the positioning of the dome.

 

This lens when zoomed between 9 and 18mm moves in and out more than an inch so in effect the nodal point changes depending on what AOV you are using.

 

Do you know if anyone has done tests on corner sharpness at different FLs for that lens?

[lufik 1]

Corner sharpnes at 9mm is not terrific and in my experience is not improving much with stopping down (I have tried up to f14 and would not call it great). But comparing with samples from other lenses behind domes, I start to get feeling I could be expecting too much ;-) The issue disappears at around 11mm and up. I have samples ready, but do not know how to post them here, sorry.

[Storker 13]

Corner sharpnes at 9mm is not terrific and in my experience is not improving much with stopping down [...] The issue disappears at around 11mm and up.

 

Thanks for the tip, I'll try zooming in a tiny bit the next time I'm shooting

 

 

 

I have samples ready, but do not know how to post them here, sorry.

 

Do you have them online somewhere else (Flickr, Ipernity, Google+, Picasaweb, tinypic, imgur, photobucket...)? If you have, it's easy to link to them here. You can also use the "Attach files" function in the advanced edit window (AKA "More reply options").

Edited January 10, 2014 by Storker

[lufik 1]

Thanks for tip how to attach pictures. Here is 100% crop of center and corner; shoot at 1/60s at f13, ISO 400.

[nudibranco 26]

To respond to Manta ray... the 3.5" dome is very very nice for the 8mm FE lens.

In the Nauticam chart it is listed under part number 36131 - port for:

1) Nikon 1 NIKKOR 10mm f/2.8
2) Panasonic LUMIX G 14mm / F2.5 ASPH

 

I quickly tried the 4.33" with a 30mm extension and the 9-18mm lens. I tried it in a big tank but could not resolve whether it is better or worse than the recommended 4" port. However the 4.33" with extensions becomes bigger than the 4" one so it loses some of its flair... unless it gives better image or it lets the 9-18mm focus closer (my main gripe with the 9-18mm lens) than the 4 inch dome port I see little use unless you want a single port with both 9-18mm and 8mm lenses.

[Storker 13]

lufik: What FL are those pictures taken at? 12mm? I've seen noticeably worse corners in my pictures at 9mm and f/4-5.6

 

On another note, are there anyone who have tried to put a moderate closeup lens on the 9-18 to check if that could improve corner sharpness?

Edited January 22, 2014 by Storker

[lufik 1]

@Stroker - the shot is at 9mm. Corners at 9mm are not improving much when stopping down. I haven't done any scientific testing, and underwater not many things are parallel to camera. So corners are mostly even worse than the example I posted. Attached is 100% crop of center and corner of picture shot at 1/60s at f8, ISO1000, 9mm. However the pictures still print well on A3 size and look fabulous on 65" TV.

I also had the idea of using diopter and I have dry tested +4 closeup lens. The result was great magnification but unacceptable pincushion distortion. I've decided to return the diopter and test again with +2 when local waters get warmer. If you find any information or samples, please, share.

Edited January 22, 2014 by lufik

[Storker 13]

I started wondering if a closeup diopter might improve corner sharpness, so I went on Ebay and bought a set of Vivitar closeup lenses, 52mm, +1, +2, +4 and +10 diopters. Made it to the pool to do some tests with a couple of the lenses. Setup: Nauticam NA-EM5, 4" WA port, no diopter, +2 diopters and +4 diopters, no flash. All posted pictures are taken at 9mm.

 

I had to apply some rather heavy distortion correction in Lightroom. For +0 diopters I used -10, for +2 diopters I used -26 and for +4 diopters I used -32 at 9mm. At 18mm, I used -10 regardless of diopter. In addition to the distortion correction, I did some angle and Keystone correction to get comparable pictures (all shot freehand while freediving), but that correction was rather minor.

 

First picture is the test chart (image downscaled), printed on A3 paper, laminated and brought to the pool. Set up against the pool wall the chart sagged a little, so the images are far from 100% quality. However, to me they look rather convincing...

Second image is a composite (1:1 crops). Top left corner of the chart, 1:1 crop. Left column: +0 diopters, center column: +2 diopters, right column: +4 diopters. From the top: f/4, f/5.6, f/8 and f/11.

Edited February 18, 2014 by Storker

[Storker 13]

Even with the +4 diopter, I was able to focus at infinity, however I lost some AOV due to the distortion correction. The third image is a composite of 1:1 crops of the center section of some distance shots, at f/4. From the top: +0, +2 and +4 diopters.

The fourth image is a downscaled composite of the full distance shots. From the top: +0, +2 and +4 diopters.

 

 

Edited February 18, 2014 by Storker

[Storker 13]

Conclusion: I'm going to use the +2 diopter in the future when I'm using my 9-18mm behind the 4" dome port. The loss of AOV is rather negligible, and the improvement in corner sharpness is dramatic. While even f/11 gives noticeably poorer corner sharpness without diopter, the +2 diopter gives acceptable corner sharpness already at f/5.6 and pretty good at f/8. The distortion - and the CA - caused by the cheap closeup diopters can be handled quite acceptably by Lightroom.

[coroander 16]

Fantastic work!! I've always held off getting the 9-18mm and the 4" port because the corners were just too soft. That you can use a +2 diopter to sort this out is fantastic and the improvement is dramatic. Many thanks!

[Storker 13]

You're welcome.

 

It was a bit of an eye-opener for me, too. Just note that:

 

1. I was using ordinary topside closeup lenses, not wet lenses.
2. The overall quality of the pictures is rather crappy. Due to low light, I shot at ISO2500-3200, with shutter speeds of 1/30-1/10. The excellent stabilizing system of the E-M5 handled the low shutter speeds quite well, but some general softness due to high-ISO noise and slow shutter speeds is unavoidable. I didn't apply any noise reduction or sharpening except Lightroom's standard settings.

 

 

I'd like to know why the diopters improve corner sharpness. Are the edges of the virtual image too close to the lens, so the camera can't focus properly, or is there some other reason that I don't understand?

 

 

On a lighter note, it was an interesting experience. I brought some weights to help me keep under while shooting, but 8lbs wasn't enough to sink me with full lungs. The only way I was able to stay stationary at the bottom was by exhaling as I went under. It's quite interesting to lie still on the pool floor with empty lungs; the breath-holding experience is rather different from free-diving with full lungs...

Edited February 19, 2014 by Storker

[oskar 6]

Greit experiment!

So your conclusion is to always use the +2, right? Part from the added distorsion, what are the drawbacks of the diopters?

What is the actual subject distance by the way?

How does the distortion look change with the diopters, more barrel-like?

Cheers

/O