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Nicool

Member Since 08 Aug 2008
Offline Last Active Yesterday, 10:53 PM
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Posts I've Made

In Topic: Are you happy you changed from DX to FX?

31 January 2016 - 01:49 PM

 

And then you get into the whole issue of "real world" images compared to test bench images. Sure, the test bed may show the images are sharper. But that can be very hard to see in a well-shot, well-focussed image shot at 25m in a ripping current. 

thanks for the feedback Tim, 

this is why i am interested to see whether users see in the field the same kind of gap which test benches highlight


In Topic: Are you happy you changed from DX to FX?

31 January 2016 - 07:10 AM

Another thing to consider is the quality of Nikon's FX lenses vs their DX lenses.  As I look through the lens tests on the German website PhotoZone.de, and compare the Nikon 105mm f2.8 VR Micro-nikkor vs the Nikon 85mm f3.5 (non-VR) Micro-nikkor, the resolution results they show indicate that the 105mm f2.8 lens out resolves the 85mm 3.5 significantly (by about 20% or more) at the apertures (f11-f22) that would be most useful for macro shooting.  Comparing Photozone's test results for the Nikon 16-35mm f4 VR vs the 10-24mm f3.5-4.5 (again non-VR) the resolution numbers again favor the 16-35mm by about 25% at most apertures and focal lengths.

 

This is not surprising.  Nikon considers FX their pro format. The FX equivalent lenses are more expensive and physically larger.  And better optically.  So if you want the best image quality from your Dslr, FX is the way to get it.

 

Fred 

 

i guess this is kind-of equivalent to my above point: DX lenses are usually less able than FX lenses in getting lots of megapixels out of the sensor. I didn't mean it was impossible (for instance some Zeiss expensive lenses get almost 100% of the resolution out of the D7100/D7200, but it's a 5000 USD lens...).


In Topic: Are you happy you changed from DX to FX?

30 January 2016 - 06:09 AM

dear all,

 

I've read this thread with attention as i am myself hesitating between a DX or FX body for my next housing.

Previously i had been using a D300, then D7000, then OM-D EM-5, and i'd like to go back to Nikon DSLR.

 

I am bringing this thread up because it includes lots of useful considerations already, except maybe the following one, on which i'd love to have some feedback: what would be the resolution (megapixels) you can really get out of these setups (meaning not the advertised sensor resolution)?

 

In my case i am hesitating between a D7200/D7100 and a D750, which are both 24 MP sensors. I've spend quite some time browsing the tests on DxoMark.com, and when looking at the lenses we typically use underwater, it seems the latest DX cameras are far behind the FX in sharpness:

1/ take the venerable Nikon 105mm Micro AF-S: it renders only 12 MP on a D7100, vs 19 MP on a D750

     => on a side note, the Sigma 105mm F/2.8 EX DG OS HSM manages to resolve 15 MP out of the D7100, but i believe it's not popular underwater for some reasons.

2/ similar result for Nikon 60mm Micro AF-S: it renders only 11 MP on a D7100, vs 17 MP on a D750

     => on a side note, the Tamron 60mm F/2 Macro manages to resolve 14 MP out of the D7100, but i believe it's not popular underwater for some reasons.

3/ consider the Nikon 10-24mm: it renders only 10 MP on a D7100, whereas the "equivalent" Nikon 16-35mm gets 16 MP out of a D750.

4/ unfortunately the fisheyes haven't been tested, it would have been interesting to see how the Tokina 10-17mm performs.

 

My conclusion after reading these measures: the best resolution i one can really get out of a D7100/D7200 for underwater photography is in fact 10-12 MP, whereas it's about 16-19 MP on a D750 (in fact it would even be less on both, due to the imperfections of dome/ports). 

I had read multiple times in this thread that the IQ of FX cameras was better than DX, but i thought it was in the extreme cases where you close aperture (diffraction coming up quicker on DX) or increase ISOs (noise damaging details quicker on DX). 

I didn't think the difference would be so significant when shooting at low ISO, with lenses pretty opened.

 

 

What are your thoughts on this? Do real-life experiments tend to confirm such a statement?

 

regards

Nicolas


In Topic: Leica XU

24 January 2016 - 02:31 PM

I would have been quite interested if it were rated to 40m/120ft.
IMHO if you have to put it within a housing it makes it just another camera.
I am wondering if some housing manufacturers would built wet lenses that could go straight on the housing (hence minimizing optical defaults)

In Topic: Canon 7D system, nauticam housing, port, 45 viewer, lens and zoom gear

09 January 2016 - 04:20 PM

Still available:
Nauticam 7D housing with leak detect, 4 x ball mounts, lanyard carry handle £1000
Zen optical glass 100mm dome port (tokina 10-17) £450
Tokina 10-17 £380
Tokina 10-17 zoom gear £75
SubSee Magnifier (+5 diopter) £120
Holder for diopter £50
8 clamps, Nauticam & Ultralight £120
4 arms (6 og 9 inch), StiX incl ffloating elements £120
I-torch video Pro6 light £300
2 Sea&Sea YS-D1 £640
2 optical cables £100

Hi Jans,
Is the zoom gear still available for the tokina? I would be interested, regards
Nicolas