Cannon G7X vs Sony RX100

Hi All,

I've been diving for quite a few years and have owned a few U/W cameras starting with a Nikonos V and now have a Nauticam/D800 system though in my own opinion, my pictures never really got to the level I desired. Part of the problem is that I only get to dive a couple of times a year if I'm lucky and each time is like having to familiarize  the operations all over again. I'm getting older and got tired of hauling gear a few years ago so I stopped shooting. My girlfriend learned to dive a couple of years ago and now wants to get an underwater camera. She doesn’t want anything large or complicated so I have seen the Canon G7X and the Sony RX100 mentioned on several sites. Does anyone have any opinions between these two. I realize there are several iterations of both and I’ve heard that the Sony models differ in their ability to change from wide to macro while diving. Any opinions or advice will be appreciated.

Thanks

3 hours ago, ccoulter said:

Hi All,

I've been diving for quite a few years and have owned a few U/W cameras starting with a Nikonos V and now have a Nauticam/D800 system though in my own opinion, my pictures never really got to the level I desired. Part of the problem is that I only get to dive a couple of times a year if I'm lucky and each time is like having to familiarize  the operations all over again. I'm getting older and got tired of hauling gear a few years ago so I stopped shooting. My girlfriend learned to dive a couple of years ago and now wants to get an underwater camera. She doesn’t want anything large or complicated so I have seen the Canon G7X and the Sony RX100 mentioned on several sites. Does anyone have any opinions between these two. I realize there are several iterations of both and I’ve heard that the Sony models differ in their ability to change from wide to macro while diving. Any opinions or advice will be appreciated.

Thanks

The issue with these cameras is that the 24/28- 70 or so lens behind a flat port is not that wide, so for UW use a wet lens to give you a wider field is something that will definitely help you photos.  The newest generation RX-100 use a 24-200 lens which gets very long so need a separate short port to use with the wet wide lens.  This then means you can't use all of the zoom range for fish portraits etc. 

Backscatter have a review of the best advanced compacts here:

https://www.backscatter.com/reviews/post/Backscatter-Best-Underwater-Compact-Cameras

They like the Panasonic LX-10, though not everyone agrees with the choice.  They do list pros and cons for each model and you can see what housings are available for each.  The thing that will make the biggest difference is shooting with a strobe, so I would definetely consider budgeting for at least one strobe.  Have a read and see if that brings up anymore questions.

Chris,

Thanks so much for your reply. I will read the Backscatter article on the Panasonic. I have two Ion Z-240s in my gear that are virtually un-used and will probably keep one or both for her camera. I'm getting ready to list the rest of my Nauticam/D800 system for sale.

Thanks,

Charlie

I am going to hate myself for wading into this but here's some insights.......

I used DSLRs mostly APS-C to my last Canon SL1, an APS-C size sensor of only 12 megapixels fall over approximately 15 years (2001-2015.) 

In 2015 I tired of carrying even the DLM Ikelite Canon SL1 housing, dual small DS51 strobes, cords, etc. After a Philippines trip with a 1" sensor Canon G7X II alongside my Canon SL1   I came home and sold all my SLR items. Everything.......Canon SL1 camera bodies (2), 3-4 lenses, surface flash, underwater housing and strobes, cords, etc.

I kept the compact Canon G7X II and in 2021 used a Sony RX100 VII for an African safari and snorkeling with humpback whales in Moorea' French Polynesia.  Used it and my Canon G7X II both in Fantasea housings. 

You can easily make decent prints from 1" sensor in these compacts. I try helping UW photographers I meet but am certainly not an Adobe Photoshop / Lightroom whiz.

In fact I shoot JPEG primarily using Apple's free Photos software plus maybe my iPhone Snapseed.

Many I try to help don't believe the easy tips I give them work and go home without decent holiday pics 

In the interest of trying to help here goes my simplified summary:

* Manually set your ISO for tropical diving to lowest (125 on my Canon G7X II) as this has better dynamic range.

* On the mentioned 1" sensor cameras shoot in M, manual adjustment mode.

Pick a "good for 90%" shutter speed / f-stop"  setting to start with. 
I suggest lowest ISO, shutter speed of 1/125 and f5.6 on any 1" sensor as the best choice for wide to medium focal lengths using any strobe(s). 

NOTE: Stopping to a higher number (smaller f-stop) simply creates "diffraction" or subtle blurring of the image while not gaining much more depth of field.

I watched a Sony Ambassador's Youtube presentation on the Sony RX100 VII before using mine for an African safari in 2021. He repeatedly mentioned on the surface f4 was like f11 on a FF sensor and after shooting a thousands of pictures above and below I agree. Going to extreme f-stops especially on compact sensors will not gain you much depth of field but will introduce diffraction.  

* I've shot thousands of underwater photos with two small Inon S2000 units on the S-TTL mode. I love the small size for travel and diving.

Shooting S-TTL means you set your camera's pop up flash to TTL (AUTO in most cameras menu flash setting) transmits through your fiber optical cords up to the strobe. Yes, your camera's recycle time will be longer but very few subjects sit still long enough without moving a foot closer, farther away etc. for 90% of UW shooters to re-adjust manual flash adjustment. I know this goes against most of what it touted on Wetpixel.

Without debating people who say TTL doesn't work don't understand it.....Your flash needs to be close enough to bounce off the subject, hit your camera's sensor and if not needing the flash to dump full power will automatically "quench" or cut off the flash to a lesser output. 

* The biggest problem people don't understand shooting flash is if you can't reach out and almost touch the subject you'll never light it no matter what flash you have

Bumping iSO may help a bit (maybe 1' farther away?) but water distance from camera to subject will filter out any strobe's power and color.

Looking at thousands of compact camera's picture's EXIF data 99% of my best shots were taken at ISO125, Shutter speed 1/125 and f5.6. 

I confess these days I'm lazy and more a wide angle / medium distance fish shot photographer. I already have tons of nudibranchs and other macro shots. It simply doesn't interest me as much is all. 

Search for my name on Scubaboard for other sample pics and other comments but these parameters rule in my book.

The 1" larger sensor compact cameras can capture great images to use however one desires.

I prefer the Canon G7X II for ease of menus and color balancing in ambient light and have since sold my Sony RX100 VII.

Just one old guy's opinion 

David Haas

31 minutes ago, dhaas said:

Without debating it people who say TTL doesn't work don't understand it.....Your flash needs to be close enough to bounce off the subject, hit your camera's sensor and if not needing the flash to dump full power will automatically "quench" or cut off the flash to a lesser output. 

* The biggest problem people don't understand shooting flash is if you can't reach out and almost touch the subject you'll never light it no matter what flash you have

A problem with shooting TTL flash and triggering off a pop-up flash is that those pop-up flashes tend to have a fairly short maximum pulse duration - I'm not sure about RX100 series, but on Sony A6xxx series, I recall seeing measurements that have shown it to be slightly under 1ms. A full dump on an Inon Z-330 is approximately 3.3ms long, so triggering one in TTL mode off a pop-up flash is going to limit it to less than half of its maximum power output.

Another issue is managing metering modes - the default multi metering mode tries to average out the entire frame, which can lead it to overexpose the background as it vainly tries to light up the water column. Center and spot modes are more reliable, but they limit your compositional choices.

1 hour ago, Barmaglot said:

so triggering one in TTL mode off a pop-up flash is going to limit it to less than half of its maximum power output.

Yeah, I heard about this when I was using the pop-up on a D800 to activate my Z240 strobes. It persuaded me to get a (UWT) trigger as it was apparent you could not get a full dump from the strobes triggering from the D800's pop-up.

And then, of course, ?most manufacturers removed the pop-ups anyway.

Both good comments and as mentioned I don't want to wade into a TTL versus Manual flash shooting debate......Use whatever works for you, dive often and enjoy yourself!

Both Barmaglot and TimG who I respect shed insights for various ILC cameras if they have a built in flash. Hot sho flash triggers obviously solve a lot of those problems. 

I was mainly referring to small compact camera's built in flash for triggering. 

One difference I noted between my Canon G7X II (and III and original Canon G7X I owned) was my Sony RX100 VII could NOT be set to fire a lower power non-pre flash setting :( 

Basically the Sony was all TTL but you could dial in some minus flash (dial it waaaayyyyyy down) and experiment depending on what flashguns you have. Then you could tell if it would just trip a strobe in Manual.

The Canon G7X II / III models can set either AUTO (TTL) or Manual  Flashin 1/3 steps. Want to trip an underwater flash in manual mode simply push a couple buttons and dial it down to 1/3 output and no pre-flash. I played wiht this and my Inon S2000 flashes with my little magnet in the back. Fires everytime but I'd have to estimate flash power to subject distance, ISO, f-stop I chose, etc.   Too much work for me .......

I group Flash Control as one of 5 saved My Menu items in Canon's menu choices. Super fast and easy to get to if desired.

Food for thought and just one long time photographer's insights after many, many years.

DH

Getting close is always the best recipe for UW shots, whether you are using TTL or manual.   From what I have seen on here TTL seems to work better on some models than others.  After all the strobe is just built to imitate the flash duration that the camera has calculated for the shot.  it stands to reason that some cameras could do better at UW TTL than others, but the dominating factor seems to be filling the frame with subject- the cameras seem to struggle to know what to do if there is a lot of water in frame.  So it makes sense that getting close will help you out.

While there may be limitations caused by the flash duration on compacts, the 1" sensor cameras are less likely to run into it, they have a 2.7x crop factor and this also applies to depth of field f5.6 x 2.7 = f15 - f 5.6 gives you the same depth of field as f15 on a full frame camera which would f10 on a APS-C - all with the same framing of the subject.  The consequence of this is that you can shoot the compact at f4.5-5.6 range which means your flash power is turned down quite a bit.  Manual will of course help with battery life which is limitation with compacts - but not all compacts allow manual flash output.  Sony and Panasonic do not. 

There's no doubt you can take some great shots with these little compacts- after a flash the biggest thing you can do is add a wet wide lens of some sort - it allows you to get closer and because things look small in frame encourages you to get closer. 

4 hours ago, ChrisRoss said:

the dominating factor seems to be filling the frame with subject- the cameras seem to struggle to know what to do if there is a lot of water in frame

This depends on the metering mode that you've set. For example, my A6300's manual says this:

So, when 'Multi' is selected, whether manually or automatically, such as in when shooting in auto mode, water in the frame has a high potential of confusing the camera, but 'Spot' is generally accurate so long as you place your subject in the middle of the frame. For static scenes, you can also use AEL function to meter with pre-flash, then recompose and shoot, but I've found this to be too much hassle to use operationally.

7 hours ago, dhaas said:

Both Barmaglot and TimG who I respect shed insights for various ILC cameras if they have a built in flash. Hot sho flash triggers obviously solve a lot of those problems. 

I was mainly referring to small compact camera's built in flash for triggering. 

It doesn't matter if a camera is ILC or fixed-lens - the salient point is that without an LED flash trigger, using TTL mode will limit the output of underwater strobes. Yes, small-sensor cameras are more tolerant of lower flash power, but the issue is still there. You can kinda-sorta get the best of both worlds if you use a compact camera with a hot shoe and a flash trigger instead of pop-up flash, but these are quite rare - Canon G1X series is not really a compact, Panasonic LX100 uses an M43 sensor, leaving Sony ZV-1 as the sole entry. Interestingly, there are two housings out there for ZV-1 - Ikelite and SeaFrogs - which makes it an interesting alternative to RX100V.

7 hours ago, dhaas said:

Basically the Sony was all TTL but you could dial in some minus flash (dial it waaaayyyyyy down) and experiment depending on what flashguns you have. Then you could tell if it would just trip a strobe in Manual. 

I'm not sure what this is meant to accomplish - are you trying to make the pre-flash weak enough so that the strobe wouldn't detect it? I don't know whether or not modifying flash compensation setting would affect the pre-flash duration; it stands to reason that it wouldn't - the sensible thing, from the camera's perspective, would be to meter with a fixed-duration pulse, and then apply flash compensation setting to the final calculation. Regardless, if you want to shoot in manual mode when triggering off a Sony camera, just enable pre-flash cancellation on your strobes... although, I suppose, with the really annoying magnet in/out thing on Inon strobes, this is not something you'd want to do mid-dive either.

Another issue that I ran into when shooting TTL is the pre-flash delay - it takes about maybe half a second between trigger press and the main pulse, which is usually not an issue, but can be annoying when you're trying to catch a subject exhibiting some dynamic behavior, such as a fish yawning - if you don't anticipate the action and press the trigger ahead of time, then by the time the flash fires, that precise moment you're after may be gone.

For years using hard wired TTL Ikelite housings their instructions stated use CENTER Weighted metering to improve accuracy of TTL strobe(s). I usually did unless I forgot to switch my camera metering from the MATRIX setting.

Either way I didn't see a huge difference in TTL accuracy.

As to dialing down the compact Sony RX100 VII TTL output I only tried it a couple times with the magnet in my Inon S2000 strobe(s).  This would trip the strobes set to MANUAL mode and seemed to speed up the Sony RX100 VII flash recycle time but not as fast my Canon G7X II in MANUAL flash set to  only 1/3 output.

After trying S-TTL (Inon strobe protocol) and MANUAL flash I settled on S-TTL delivering 125-150 shots per little Canon NB-13L battery. I have several and can open my Fantasea housing after drying, pop a new battery in and re-seal it in under 60 seconds.

Not saying it's the best set up option but has worked for me over 6 years since converting to compact underwater shooting.

DH