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04-08-2018, 09:20 AM - 5 Likes   #1
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Fish-Eye Options for the Q

Shawn67's post on the Fujinon 2.7mm f1.8 c mount lens in the adapted lenses for the Q section inspired me to purchase one.

They are common on eBay, usually in a CCTV fixture, I got mine for $70. As Shawn mentioned, you do have to shim it slightly (thin brass or even paper) to get proper focus. I also have the Pentax 03 so I thought I'd run a test to check on the coverage of various options.


First is the standard 03 on a Q7:



Next is the 03 lens on the Q7 with its contacts covered with a curve of thin plastic or paper, this defeats the auto cropping of the Q7 and gives a wider view, albeit with a slight amount of cropping on the corners:




Finally, the Fujinon on the Q7:



As you can see, there is a much wider field of view, with just a tiny bit of vignetting on the corners. The Q mount has a slight bit of play in it so you might get uneven borders. The image quality of the two lenses is similar, the Fujinon might be a little sharper but has a little more fringing on the extreme edges. Both lenses have fixed F-stops, the three stop difference makes the Fujinon much more usable for available light hand-held. With SR on it is possible to get good hand-held exposures at 1/4 second. The Fujinon is more limited in its focusing capabilities, you can unscrew it slightly to get a closer focus, but it is tricky. A thicker shim will get you into extreme close-up territory, but the bulk of the lens will make it hard to use without causing a shadow.

So, for about the same price (you'll need a c mount adapter for the Fujinon), there are two viable fish eye options for the Q, not counting auxilliary lenses. The Fujinon makes a complete circle on m43, good for full horizon shots. There is also an adjustable stop version but you'd probably have to buy that new, it is in stock at B&H for $459, although the depth of field of the wide open version is probably deep enough for most applications, diffraction effects would probably creep in if it was stopped down much.


Last edited by Cipher; 10-12-2018 at 09:41 AM. Reason: typo
04-08-2018, 10:17 AM   #2
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Cipher, thanks for this comparison. Fuji looks super and has a much wider view. Obviously it loses to the 03 on compactness.

A few questions:

1. With no adjustable aperture, is it possible to shoot outside on a sunny day?
2. Is it difficult to remove the lens from the security camera?
3. Have you tried the lens on a M4/3?

I have a 03 but this lens is tempting. Wider & low light on the Q are big bonuses. The 2 second long shutter speed can be very limiting at f5.6. Being able to use this on my Olympus m4/3, as a circular fisheye, is great. Lens seems like a no brainer for me.

Love the guitar wall!

Thanks for sharing,
barondla
04-08-2018, 10:39 AM - 1 Like   #3
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QuoteOriginally posted by barondla Quote
A few questions: 1. With no adjustable aperture, is it possible to shoot outside on a sunny day? 2. Is it difficult to remove the lens from the security camera? 3. Have you tried the lens on a M4/3?
1. Yes,barely, ISO 100, 1/6400 - 1/8000 of a second
2. No, remove a couple of screws, a plastic shroud around the lens unclips and the lens simply unscrews. See Shawn67s post. You will have to experiment with the shim, the flange to sensor distance is very critical.
3. No, but I have seen pictures taken with it. Bear in mind that the Q7 sensor has a finer pixel pitch than the m4/3 and crops in.

I have used it in available light; it is a lot of fun with groups of people.

The guitar wall is my other hobby/obsession, thanks.

Last edited by Cipher; 04-08-2018 at 10:47 AM.
04-08-2018, 11:33 AM - 2 Likes   #4
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Interesting find! Is the version in the security cam a regular C mount then?

P.S. I have a Coastal Optics 2.16mm f/3.3 in C mount that I accidentally found (not eBay but similar price), but have never ever seen another for sale anywhere. I think I bought the ONE lens on the internets.. lol!
I use it @5.6 and made some very wide views of the inside of my kayak .. https://kayakfari.wordpress.com/2016/02/23/the-space-within-exploring-a-sea-...he-inside-out/

04-08-2018, 11:45 AM - 2 Likes   #5
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QuoteOriginally posted by kayakfari Quote
Interesting find! Is the version in the security cam a regular C mount then?

P.S. I have a Coastal Optics 2.16mm f/3.3 in C mount that I accidentally found (not eBay but similar price), but have never ever seen another for sale anywhere. I think I bought the ONE lens on the internets.. lol!
I use it @5.6 and made some very wide views of the inside of my kayak .. The space within – exploring a sea kayak from the inside out! | kayakfari ( kayak .. far .. i )

Yes it is a regular C-mount, I put it on the q7 with a cheap adapter.

That 2.16mm lens you found is even trippier!

That makes three fish eyes for the Q system!
04-08-2018, 02:42 PM   #6
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QuoteOriginally posted by kayakfari Quote
Interesting find! Is the version in the security cam a regular C mount then?

P.S. I have a Coastal Optics 2.16mm f/3.3 in C mount that I accidentally found (not eBay but similar price), but have never ever seen another for sale anywhere. I think I bought the ONE lens on the internets.. lol!
I use it @5.6 and made some very wide views of the inside of my kayak .. The space within – exploring a sea kayak from the inside out! | kayakfari ( kayak .. far .. i )
Creative kayak photos! Haven't ever seen that view of a kayak. Terrific concept and execution.

Thanks for sharing,
barondla
04-10-2018, 11:50 AM - 1 Like   #7
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Thanks Barondla - fun in the Q continuum!
04-17-2018, 06:47 AM   #8
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Couldn't resist ordering the Fuji. It just arrived. Removed it easily from the housing, but there is a problem. Can't get the chrome adapter ring to unscrew. Using full hand strength and it won't budge.

Hate to contact seller about something so dumb. Considered wrapping the chrome ring in something and using hand tools to remove. But that might scratch up the chrome ring, which I don't care about. However, if I have to return it the seller might object.

Any ideas?
Thanks,
barondla

04-17-2018, 07:52 AM   #9
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Hmm... mine came right out. Maybe some heat to the chrome ring (soldering iron), yours might have some locktight on the threads. The tapping trick for stuck filter rings might work too, with a drop of WD-40 soaking in for a few minutes where the threads join the ring.

Last edited by Cipher; 04-17-2018 at 08:10 AM.
04-17-2018, 05:22 PM - 2 Likes   #10
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QuoteOriginally posted by barondla Quote
Couldn't resist ordering the Fuji. It just arrived. Removed it easily from the housing, but there is a problem. Can't get the chrome adapter ring to unscrew. Using full hand strength and it won't budge.

Hate to contact seller about something so dumb. Considered wrapping the chrome ring in something and using hand tools to remove. But that might scratch up the chrome ring, which I don't care about. However, if I have to return it the seller might object.
Congrats on the Fuji!

I had the same issue when i received mine. Apparently, the lens is bonded to the chrome ring with some kind of cement. I got to unscrew it by heating the mount with a hair dryer and applying some extra force with hand tools. I wrapped the lens in fabric to prevent it from being scratched but nonetheless made a small mark next to the mount.

It's a very good lens and well worth the fight! Go for it!

Cheers!

Abbazz

Last edited by Abbazz; 04-17-2018 at 06:02 PM.
04-17-2018, 07:29 PM - 1 Like   #11
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SUCCESS!

Cipher, Abbazz thanks for your help. Used all your tricks to get that chrome ring off. Dropped penetrating oil into the adapter. Placed lens into the freezer for 1.5 hours. Removed lens and while still frozen blasted the chrome adapter with a heat gun I use for shrink wrap. Quickly wrapped adapter in electrical tape and used a special round jaw vice lock to remove. Held lens in other hand.

Already have brass shim material to adjust focus. The Olympus m4/3 C mount is on the way from China. Time to have fun.

Thanks again,
barondla

---------- Post added 04-17-18 at 10:02 PM ----------

Anybody figure out a lens cap for the front of this lens? Need a way to carry it in the bag.
Thanks,
barondla
05-05-2018, 11:50 AM - 1 Like   #12
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Nice, glad others are enjoying the Fuji too. It is a great little lens for not much money. As far as a lens cover I have just used a small velvet cinch bag over the lens so far. At some point I will see about trying to 3D print a lens cover for it.

Shawn
06-05-2018, 09:16 AM   #13
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I got my copy for special price, but I'm finding that I need to file down my C->PQ adapter instead of shimming.
Also I found a perfect fit lens cap for it from Tropicana!
The orange top is the exact diameter to fit over the lens and is deep enough. Just have to dremmel out the inside ring and fins.

Another, maybe better looking option could be a rear lens cap for EOS lenses, but it may not be deep enough - looks very close!


06-05-2018, 11:45 AM - 1 Like   #14
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Ok I can confirm the rear lens cap for EOS has just enough clearance (about 1mm) in depth to work. You just need to dremmel out the inside and sand it a bit, will slide right on.
As far as C->PQ adapters, I went through several. The adjustable ones worked the best and I found one that needs no shim. The one piece solid adapters need too much shiming imho to seat properly.
Still not convinced about absolute flatness to film plane, mine looks good, but a fraction of a millimeter can throw it off. Not sure if there are any real quality adapters like these!

The lens itself is reasonably sharp, about the same as the 03, however this one suffers some serious PF outdoors in sunlight. So this is an interesting FE that covers about 180 on the original Q, but will be best used in B&W or low light where the 03 is too slow. If you can pick it up for less than $50 it's fun and certainly good enough for web use.
06-05-2018, 06:22 PM   #15
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QuoteOriginally posted by kayakfari Quote
I got my copy for special price, but I'm finding that I need to file down my C->PQ adapter instead of shimming.
Also I found a perfect fit lens cap for it from Tropicana!
The orange top is the exact diameter to fit over the lens and is deep enough. Just have to dremmel out the inside ring and fins.

Another, maybe better looking option could be a rear lens cap for EOS lenses, but it may not be deep enough - looks very close!

Please post a color photo of the Q and lens with OJ lenscap! 👍🏻😂
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