There have been a number of posts recently discussing the merits of an 8-15mm lens with a teleconverter. The 8-15mm fisheye lenses are great performers, but can feel limiting because they are either 8mm (circular) or 15mm (wide fisheye). If you are dealing with CFWA or a Wide subject just a bit out of reach like Sharks, then a bit more reach might be welcome. A 1.4x Teleconverter delivers just that sort of solution.

With the 1.4tc the 8-15 fills the frame without clipping right between 11 and 12mm. This opens up a useful range from 11-15mm or the magnified equivalent of 16 - 21mm.

I just completed a trip to the Pacific side of Vancouver Island in an area called Barkley Sound. There is a quaint dive lodge out there called Rendevzous Dive Adventures that runs a very nice operation. I mostly shot the Nikon 8-15mm AF-S lens with 1.4tc (kenko) under a Nauticam 140mm dome. I used my 3d printed 40mm port extension that continues to perform perfectly after about total 25 dives. I did a couple of dives with the WWL-C / 25-50mm combo and tried to take some comparison shots.

Below are two similar images taken with both combos. The photos are uncropped and very lightly edited.

Nikon 8-15mm with 1.4TC, @12mm, f10@1/25s iso400, Pair of Retra Maxi strobes with 4500k filters

WWL-C with z24-50mm, @24mm, f14@1/50s iso400, Pair of Retra Maxi strobes with 4500k filters

And a comparison image of the 8-15mm + 1.4tc @ 15mm.

Nikon 8-15mm with 1.4TC, @15mm, f8@1/30s iso500, Pair of Retra Maxi strobes with 4500k filters

This image needed a BSXT pass as there was a lot of fuzz stirred up by multiple divers nearby.

Edited yesterday at 08:27 PM1 day by Dave_Hicks

Conclusion:

• To my eye the quality off all of these images is quite good.

• Even at fairly low shutter speed of 1/20th second an mid-range apertures of f9 the images are quite sharp and the corners look acceptable.

• The 8-15 + 1.4 outperforms the WWL-C setup in the corners by a small margin.

I don't see any significant negatives to adding the 1.4tc to the 8-15. However, on occasion you will likely miss-zoom at the 11-12mm range and slightly clip the frame. A minor crop will take care of this.

The Canon 8-15 can lock out so it won't zoom below 10mm which can help stop you going too far. From reports I've heard the 8-15 is the sharper lens compared to the 8-15 so likely will perform as good or better with a 1.4x.

16 minutes ago, Chris Ross said:

The Canon 8-15 can lock out so it won't zoom below 10mm which can help stop you going too far. From reports I've heard the 8-15 is the sharper lens compared to the 8-15 so likely will perform as good or better with a 1.4x.

Huh? Which 8-15 is sharper than the other 8-15?

With the Nauticam 140mm dome setup, 10mm is too far back already. The vignette is at 11 or lower. I was thinking about modifying the zoom ring to disallow it from going back any further than where it clips. It should just take some specific alignment to make it work.

The canon is the sharper of the two, but both are sharp lenses. The 10mm lockout is based on using on APS-C. I imagine designing a custom lockout would be quite a feat.

I primarily use a Nauticam water contact lens, normally the WACP-C or WWL-1B for a smaller rig.

With that said, I find the 8-15 +1.4x behind the 140 dome a perfect solution for specific wider needs. Yes, I do miss the longer zoom capabilities of the water contact options with the Sony 28-60, but image quality is never a concern with either.

Great images @Dave_Hicks and nice comparison!

Hi,

I’ve been using the Nikon 8-15mm lens in combination with a Kenko 1.4 teleconverter for several years now. I’m actually quite satisfied with the image quality. I mostly work within the 11–15mm range, shooting through a Seacam fisheye port. I’ve quickly picked a few sample images attached here.

If you’re interested, I’d be happy to provide you with detailed metadata for the images.

Best regards, Markus

58 minutes ago, Muellema said:

Hi,

I’ve been using the Nikon 8-15mm lens in combination with a Kenko 1.4 teleconverter for several years now. I’m actually quite satisfied with the image quality. I mostly work within the 11–15mm range, shooting through a Seacam fisheye port. I’ve quickly picked a few sample images attached here.

If you’re interested, I’d be happy to provide you with detailed metadata for the images.

Best regards, Markus

That's a great set! Thanks for sharing.

Great stuff @Muellema !