Tried to find some answers in previous posts, but for those that have gone before, will the Nauticam 140mm dome give a substantial uplift in IQ over a Zen DP-100? I'm using a Canon 8-15 with Sony 7AC in a Nauticam housing and have used the Zen for some decent fisheye images, but as usual, edges go soft. Both are glass domes and I'm wondering how much improvement to expect if I move to the 140mm dome. I do like the smaller sizes for travel purposes, so I didn't have much interest in going to a bigger dome.

There have been some threads discussing this, I recall there is a quality uplift, but don't recall how dramatic.

I did not test for FF, but made comparisons between Nauticam 140mm and Zen DP100 for MFT (the tread is in the old forum). If existing, the differences were minor. Maybe for FF there is some improvement with 140mm domeport. More important for sharpness in the corners is probably the correct extension and stopping down,..

A clear advantage of the 140mm dome is, that one can put the lens together with the hood into the domport, while with DP100 one has to remove the hood. I believe this can improve IQ substantially, as this minimizes the stray light from the flashes falling into the optics (together with the hood on the domeport)...

Wolfgang

Edited 15 hours ago15 hr by Architeuthis

Hi @RVBldr

The DP-100 became the mainstay of crop sensor photographers with the Tokina 10-17. In my experience, the DP-100 also produces quality images with the 8-15 when paired with the appropriate FF body.

Having a shade that is removable and replaceable shade during the dive is a bonus as is the extremely small size. For the Sony a7C (24MP FF) or even the a7C II (33MP FF), most will typically find the image quality to be solid, especially considering the shade and size aspects.

With that said, ultra high MP cameras, such as the a1, a7CR, a7rV, etc. typically benefit from the higher quality produced with a slightly larger 140 dome. There is a Nauticam version that has a removable shade, which I own. The decision to dive with or without the shade must be done pre-dive due to the 9 tiny screws that must be removed to remove the shade. While the flexibility is not as great, the quality difference makes this the right choice.

Another important consideration is if you will want to add a teleconverter to the 8-15 for a little extra reach. If so, this basically eliminates the DP-100 due to the quite noticeable "smearing" or distortion around the image edges with FF cameras. This does not occur with the 140 dome. I frequently dive with a 1.4x TC and notice no image quality difference whether with or without the TC.

Hope this helps,

chip

Edited 14 hours ago14 hr by ChipBPhoto

@ChipBPhoto Thanks Chip, good info. I find that ability to remove the shade while on the dive an upside, but the actual lock of the dome onto the shade needs some engineering. They have the o-ring that prevents the shade from backing off, but in cold water, that o-ring is a non-starter. I see it as more of a hedge against bumping the dome inadvertently. I have some nice pics with the DP-100, but also looking to the future with a higher-res camera.

2 hours ago, RVBldr said:

@ChipBPhoto Thanks Chip, good info. I find that ability to remove the shade while on the dive an upside, but the actual lock of the dome onto the shade needs some engineering. They have the o-ring that prevents the shade from backing off, but in cold water, that o-ring is a non-starter. I see it as more of a hedge against bumping the dome inadvertently. I have some nice pics with the DP-100, but also looking to the future with a higher-res cameI camera.

I started using the Zen 100mm port over a decade age with the Canon 8-15mm and later moved to the Nauticam 140mm port which if placed correctly gives better image quality in the outer parts of the frame. I to found the DP-100 port shade to be a pain to remove and reinstall underwater, in fact I just left if off completely and covered the glass with neoprene getting in and exiting. I had to do the same with the NA port. When I moved to Marelux I used the NA to MX 20mm port adapter and continued using my NA ports. When Marelux introduced their 140mm port with the bayonet sun-shade my NA-140 was the first port to go. I can now remove and reinstall easily, I put the cover over one arm and the shade over the other or clip it off on my BC. The biggest increase in IQ comes when using full frame cameras with the 140 v 100mm.

An upside to the 140mm port you may not have considered is the ability to use other fisheye and rectilinear lenses with it as long as the extensions are correct.