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Architeuthis

Canon EF lenses on MFT cameras?

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On 6/29/2021 at 11:48 PM, joncroweucl said:

Thanks for the insights, @Interceptor121

I had the Panasonic Image App running and watched through my phone as I filled the sink to see if I could notice the FOV narrowing. I was so pleased to see that there was no noticeable difference that it didn't occur to me to take a before and after shot. I'll do it next time.

After some investigation I've determined that the interior ring of the dome port is just making contact with the face of the zoom gear extension ring. This is causing increased resistance when turning the knob on the port adapter and making changing the focal length difficult. I'm also concerned that persisting and accepting this situation will eventually lead to stripping the teeth from the port adapter knob gear.

I plan to file away the exposed face of the zoom gear extension, or ask my maker friend if he can amend the design of the extension for my port. I'll post an update once I've made progress.

Hi Jon,

The extension ring is not causing problems as I am using it. I guess (as you alraedy say) that the extension is just too short in your case. I shortened one extension collar, the one for the Tokina 10-17 with 1.4x TC, where my design is a bit too long (I did not want to redesign and order a new one). I used an abrasive tool similar to the one below to make it fit:

https://www.bauhaus.at/schwingschleifer/bosch-professional-schwingschleifer-gss-23-a/p/24795795?gclid=EAIaIQobChMIxNmGjevD8QIVjP93Ch1I1QMyEAQYAiABEgLrvfD_BwE&ef_id=EAIaIQobChMIxNmGjevD8QIVjP93Ch1I1QMyEAQYAiABEgLrvfD_BwE:G:s&s_kwcid=AL!11897!3!224895636698!!!g!297667046343!!947016865!47437589459&cid=PSEGoo947016865_47437589459&pla_campid=947016865&pla_adgrid=47437589459&pla_prpaid=297667046343&pla_prid=24795795&pla_adt=pla&pla_prch=online&pla_stco=

In addition, I drilled three threads (each in 120° distance from the others) into the extension collars. These are for grub screws that are thightened with allen keys, so that the collar is fixed firmly to the zoomgear and can not get loose during the dive...

 

Wolfgang

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Any updates on this with some blue water results and recommendations??

Also just to double check, how was the autofocus when comparing to a prime fisheye??

Thanks!

Scott

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On 8/11/2021 at 9:45 PM, ScottyR said:

Any updates on this with some blue water results and recommendations??

Also just to double check, how was the autofocus when comparing to a prime fisheye??

Thanks!

Scott

Hi Scotty,

I am back now since two weeks, but did not have time yet to postprocess the greatest part of my photos: a lot of work after the holidays and finally I got a summer-flu and am lying right now in the bed...

What I can say is just what my impression is now:

To have similar corner sharpness with the Nauticam NA140 and the Zen DP100 dome, the 100 dome requires 1-2 f-stops more (this statement I will be able to check after processing my photos).

With the NA140 dome (and the Zen DP170), I do not recognize a difference in AF compared to the Zuiko 8mm fisheye (I always use "C-AF" with my EM1II). I have the impression that with the DP100 the number of slightly out of focus photos is substantial (I never noticed such photos before with the NA140 dome)..

For me the NA140 will remain the main fisheye dome. I also never used the Zuiko 8mm since I have the Canon 8-15mm (and the Tokina 11-18mm). The DP100 will be for extreme CFWA (The NA140 is, however, quite small; the difference is not big)...

 

Wolfgang

Edited by Architeuthis
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On 6/7/2021 at 1:45 PM, Architeuthis said:

Hi Jon,

Initially I have considered the Zen DP-100 (for EM1II, but this should not make a difference), but I did not acquire it. Partially the reason was the right extension: The DP-100 comes with built in extensions for the Canon 8-15mm, Tokina 10-17mm or nothing (blunt N120 version). The Nauticam 34.7mm N85-N120 is made for the Metabones 0.71x focal reducer, while one wants to use the 1x Smart adapter with Canon 8-15mm. The Smart adapter is 5.63 mm longer than the 0.71x speedbooster, so none of the versions fit as they are. I made  a table with all N85-N120 extensions that I found available from Nauticam (used with or without additional available N120 extension rings) and calculated how much the deviation (in mm) is from the recommended one:

image.thumb.png.785ba040be12dea842f77eb6c17ccdb8.png

The closest match would be the 47mm N85/N120 extension together with the Tokina version (DP-100-N120T) with only 0.3mm deviation. I refrained, however, from ordering this combination, since I was thinking in case it would not work I have an extension and a domport that is not good for any of the lenses that I have. The 34.7mm N85/N120 adapter, that is designed for the Metabones adapter, gives 2.6mm deviation at the best. I do not know, how much worse IQ would be, but I think the smaller the dome radius is, the more effect on IQ per mm wrong positioning...

I am eager to hear what Zen support tells you. I also asked them and was told that fisheye lenses are very tolerant for wrong positioning and they recommend the 34.7mm N85/N120 adpater plus 25mm extension (as listed above) - but they cannot guarantee anything...

 

Wolfgang

P.S.: I see now, that Massimo has also answered. I agree that it is better to take the Tokina 10-17mm with the small DP-100: using the DP-100-N120T with 0.71x speedbooster and Tokina 10-17mm lens is the optimum and does not need any further adjustments...

 

I was looking at the useful table you made.  But I cannot understand where you have the 25mm extension and why under the Tokina version you number are negative then positive then negative then positive depending on the adapters used...  Sorry I am confused!:dunno:

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Hi nudibranco,

 

Sorry for the confusion. The numbers are the deviation from optimum (=extension recommended by the port table) in mm, when the lens is used with the 1x Metabones adapter. Negative means the overall extension is to short, positive means it is too long. Zero is exactly the optimum...

The calculations for the different versions of the DP100 port are done with different additional N120 extensions that are available by Nauticam, in order to get the closest match to the optimum. I did not include them in the table (I thought this would be less confusing, but here we are...).

 

The used additional N120 extensions were (ordered from the 34.7mm adapter up to the 55mm adapter):

DP100-N120: 25/20/10/10/10

DP100-CR: no additional extension throughout (=None)

DP100-T: 10/10/None/None/10(None would have been the better choice for this last case, but the 55mm adapter is not really of interest for this DP100 version)

 

This reminds me that I promised to post some photos, taken with DP100 and NA140 domeports, for comparison. I will do so in the next days, when I have time. I can say already now that under real live conditions, that vary a lot from motif to motif, the differences are too small to be recognized by me...

 

Wolfgang

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Now I can show some photos that I have taken with EM1II, Canon 8-15mm and the Zen DP100 and Nauticam 140 domeport. I fear, however, that the real life situation in the sea does not allow a detailed and rigorous comparison of IQ, I guess I am not a good test photographer. Too different are the conditions, is the distance of the main subject, object distance throughtout the image, especially in the cornmers, even the f-stops differ to some extend. Photos of a test image at identical conditions would serve the task much better...

First, I repeat my subjective impressions: IQ is very similar between DP100 and NA140, but the percentage of sharp photos is higher with the NA140. I also do not notice a substantial advantage of the DP100 for CFWA, the NA140 is already small and handsome. My favorite domeport remains the NA140 and is it just because the neoprene cover fits much better on the rig...

Here two uncropped fotos (but resolution and quality greatly reduced to be postable)

DP100: 8mm; f6.3; 1/125; ISO200; 2* Z330.

DP100_full.thumb.jpg.86fb58b12705880446d26e52b0b110a8.jpg

 

NA140: 8mm; f7.1; 1/60; ISO200; 2*Z330:

NA140_all-1422.thumb.jpg.557e03c279349b798046ab5479e5f55f.jpg

 

In the next posts come parts of the images at 100% resolution (but not quality)...

Edited by Architeuthis

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DP100: center.

DP100_center-0788.jpg.3e69c415e7e04b38a47e57a09d8a7fea.jpg

 

DP100: left, lower, corner:

DP100_right_lower-0788.jpg.6e56eadf9e02b3fae451ae470e93882c.jpg

 

Since the distance in the left, lower corner, is closer than the rest, here comes a partial image of the lower rim of the photo, taken from the middel, where the distance is more comparable:

DP100_center_lower-0788.jpg.df3c9b05232bc08bc2d0e49dd1861972.jpg

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NA140, center:

NA140_center-1422.thumb.jpg.02c85549f9686a95b1d4ea35d025f6a1.jpg

NA140, left, lower, corner:

NA140_left-1422.thumb.jpg.3a99fd5fd68c1fd7358f919f4ab2e170.jpg

I hope this is, at least to some extent, useful...

 

Wolfgang

 

Edited by Architeuthis

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Thanks, @Architeuthis for the comparisons between the Zen 100mm and Nauticam 140mm domes. Very insightful.

For me, size, budget and weight were major considerations. I picked up a brand-new-second-hand DP-100CR (0.71 kg) for ~£500 on a popular online marketplace, they're not too hard to find around this price. I was also attracted to the built in extension for the Canon 8-15 FE, mitigating the need for a distinct extension ring. The DP-100 also fits perfectly in my lens and port divider bag back-to-back with my wide wet lens. I suspect any larger dome would struggle to fit in and may even lose protection or be at risk of damage.

However, compare this setup to ~£340 - 0.21kg for 30mm N120 extension ring (difficult to find second hand deals) and ~£889 - 1.45kg for the 140mm Optical Glass Dome (£1031 if you want the removable shade), you're looking at ~£729 to £871 cost and 0.95 kg weight saving. Regardless of your budget or airline carrier, these figures are significant.

I am not using the printed extension ring extender (incompatible with zen dome) so have resorted to shifting the toothed zoom ring backwards onto the first set of gripping pads so the teeth can engage with the N85-N120 adaptor port gear. This has not resulted in the zoom gear falling off (yet) so is my make do solution for now.

In my experience the ~5mm misalignment of the entrance pupil of the lens closer to the dome than is calculated to be optimal has not had a noticeable an impact of FOV or IQ. I don't have the 140mm dome and 30mm extension, so I can't perform the comparisons you have made.

See below some images with the 8-15FE on a GH5 with Zen DP-100 CR from a diving trip to the Farne Islands. There's some motion blur thanks to the 1/30 shutter speed, I should have gone faster and upped the strobe power. Overall, the setup completely exceeded my expectations. I did not observe issues with focussing at f.5-6 - f8, focus snapped on every time.

I'll be taking this setup on the WetPixel Red Sea Odyssey at end May early June and will report back with performance with WAM, CFWA and wide scenic. It will take observation of dramatic underperformance of this set up compared to others on the trip to convince me the benefits above have made to big a sacrifice/compromise to image quality or overall usability.

Note: I did experience freezing of the camera when zooming the lens with C-AF. Apparently this is common with some EF lenses on m43 bodies with metabones/viltrox adaptors. This was resolved by holding the lens release button and dismounting the lens using the port adaptor gear until camera warns the lens is not mounted, then rotating back until engaged. I must say it caused more than a small amount of panic and I've struggled to replicate this issue on dry land. Murphy is always with us when diving, I guess.

51576532754_feb1f6d9dc_c.jpg

51575042962_ace05c2690_c.jpg

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35 minutes ago, joncroweucl said:

I'll be taking this setup on the WetPixel Red Sea Odyssey at end May early June and will report back with performance with WAM, CFWA and wide scenic. It will take observation of dramatic underperformance of this set up compared to others on the trip to convince me the benefits above have made to big a sacrifice/compromise to image quality or overall usability.

Note: I did experience freezing of the camera when zooming the lens with C-AF. Apparently this is common with some EF lenses on m43 bodies with metabones/viltrox adaptors. This was resolved by holding the lens release button and dismounting the lens using the port adaptor gear until camera warns the lens is not mounted, then rotating back until engaged. I must say it caused more than a small amount of panic and I've struggled to replicate this issue on dry land. Murphy is always with us when diving, I guess.

 

=> A pity you booked the second turn of the Odyssey and not the first one. We almost would have met, since we will be on the first turn (May 22nd - 29th)... :rolleyes:

=> The seals at the Farnes Island are still on our wishlist. 2021 we were ready to book the trip, but then an immovable professional appointment of my wife (and the pandemic) got between. I hope it will be possible this summer...

=> I see in your profile that you are using a GH5. The problem of freezing is both scaring and interesting. Can the freezing be solved by switching the camera on/off (and/or updating the camera and adapter firmwares)? I never experienced freezing with EM1II and always use C-AF&tracking (my wife is using EM5II with Tokina 10-17mm fisheye and Metabones 0.71x adapter and never experienced freezing so far (she uses S-AF)...)

 

When the difference in IQ cannot be clearly seen in real live photos, it cannot be substantial (at most an f-stop, if even existing)...

 

Wolfgang

Edited by Architeuthis
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1 hour ago, Architeuthis said:

=> A pity you booked the second turn of the Odyssey and not the first one. We almost would have met, since we will be on the first turn (May 22nd - 29th)... :rolleyes:

=> The seals at the Farnes Island are still on our wishlist. 2021 we were ready to book the trip, but then an immovable professional appointment of my wife (and the pandemic) got between. I hope it will be possible this summer...

=> I see in your profile that you are using a GH5. The problem of freezing is both scaring and interesting. Can the freezing be solved by switching the camera on/off (and/or updating the camera and adapter firmwares)? I never experienced freezing with EM1II and always use C-AF&tracking (my wife is using EM5II with Tokina 10-17mm fisheye and Metabones 0.71x adapter and never experienced freezing so far (she uses S-AF)...)

 

When the difference in IQ cannot be clearly seen in real live photos, it cannot be substantial (at most an f-stop, if even existing)...

 

Wolfgang

>> A near miss! I booked the trip to Egypt when the only week available was the week in June! 

>> Let me know if you're organising a Farne Islands trip this year and I'll see if I'm available. September is the best time of year, the pups are building independence from their mothers and are incredibly curious and playful! We couldn't go 30 seconds without being inspected. Maybe we got very lucky, though I was completely unprepared for how fast they are! 

>> Re: freezing. It is a very strange issue that only happened in the thick of the action! The freeze COULD NOT be resolved by switching the camera off. The image on the LCD was frozen; zebras were flashing but the whole system was unresponsive. Thankfully disengaging the lens worked; I was fortunate the lens did not fall from the mount and end up loose in the port and dome!

I have managed to replicate this issue once outside of the housing. Having the camera in C-AF, AF-ON mapped to thumb button and held down, while quickly racking zoom on the lens. I cannot get this issue to repeat with AFS or AFF. I cannot diagnose the issue any further than establish that it exists. Given that other users have experience similar issues with other EF lenses on the viltrox and metabones adapters, I don't think 'upgrading' to the metabaones will eliminate the issue. I have a solution that I can deploy in the water, so as much as the issue is deeply annoying, it can be quickly resolved, albeit very much complicated by wearing 5mm gloves!

Edited by joncroweucl

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