TT Artisan 7.5mm f/2.0 – Fisheye Fun

I’ve always wanted a full frame fisheye lens, from when I was shooting like crazy with my DLSRs – I had an adapter than (not very effectively) turned the image into a circular (albeit cropped) fish eye, but this has never quite been my thing. I love the very exagerated lines of super-wide angle shots, and the brilliant close up effects you can get.

The TT Artisan 7.5mm f.2.0 lens is constructed of 11 elements in 8 groups, with a 7 bladed aperture, with a fixed focal length (obviously) of 7.5mm, and aperture in 1/2 stops from f/2 to f/11. It’s a curvilinear or fish eye lens with a 180° diagonal field of view (around 140° horizontal and 95° vertical).

Having been playing with Gemini and NotebookLM (more on this in a future post) I’ve built up a massive amount of data for this lens and will get a bit sciencey later) with one lovely tables, but for now, here’s some pictures.

Irritatingly, DPD and WEX could not manage to deliver on the day they were supposed to, I had carefully aranged this to come on my working at home day, the day before a days leave, and hoped to take it out for a really good test. But it didn’t come until the next day and then not until nearly 6 in the evening. I’m irritated with WEX who were very standoffish when I aksed about delivery to the DPD pickup – apparently it’s “too high value” though I have ordered expensive musical kit to there and their pickup security is tight. Had it not come the next day it would have needed to be cancelled as I would have not been able to receive it! Anyway, it pissed it down most of the day, but did clear up in the evening and I took it for a quick walk around The Ridge. There’s two main uses for super-wide lenses, especially fish-eyes – close up loveliness and crazy curves (that sounds a bit rude…)

You can see both here with the flower and nature shots and looking down the beck and up into the trees, and the abandoned hoover shop at the end of Bentley Lane.

After a number of crap weather days and too much work, I took the lens on to campus one day. Of course the other thing you can do with super wide lenses is tight spaces and corridors – check out the lift! And although the myth about Blakes 7 being filmed on Red Route has been dispelled, the corridors certainly made for an interesting subject.

Of course, looking up really acccentuates the curves (oh er, again) and some of the wonderful brutalist architecture has created great effects. And for context the distance between the blue flowers and the Roger Stevens Building is about 30 feet, showing the wonderful effects of close and far subjects combined.

What is also great about this lens is that if you have no close verticals, the fish eye effect is quite minimal – so for you can also use this quite effectively for wide angle landscapes if you compose carefully.

All in all for a shade under £150 this is pretty damn good. The wider apertures are obviously a little soft, but for the low light capabilities and the bokeh you can obtain that’s not an issue. It’s sharpest about f/8 I think – I’ll test this some more another day.

So, now for some yummy data. Tons of it. With manual lenses, it’s good to bear in mind simple focussing tricks, to get the greatest depth of field.

So here’s the hyperfocal distance table

F-Stop	Hyperfocal Distance (meters)	Hyperfocal Distance (feet)	Near Focus Limit (meters)	Near Focus Limit (feet)
f/2.0	1.41 m	4.64 ft	0.71 m	2.32 ft
f/2.2	1.29 m	4.22 ft	0.64 m	2.11 ft
f/2.5	1.13 m	3.72 ft	0.57 m	1.86 ft
f/2.8	1.01 m	3.32 ft	0.51 m	1.66 ft
f/3.2	0.89 m	2.91 ft	0.44 m	1.45 ft
f/3.5	0.81 m	2.66 ft	0.41 m	1.33 ft
f/4.0	0.71 m	2.33 ft	0.36 m	1.17 ft
f/4.5	0.63 m	2.08 ft	0.32 m	1.04 ft
f/5.0	0.57 m	1.87 ft	0.28 m	0.94 ft
f/5.6	0.51 m	1.67 ft	0.25 m	0.84 ft
f/6.3	0.45 m	1.49 ft	0.23 m	0.74 ft
f/7.1	0.40 m	1.32 ft	0.20 m	0.66 ft
f/8.0	0.36 m	1.18 ft	0.18 m	0.59 ft
f/9.0	0.32 m	1.05 ft	0.16 m	0.52 ft
f/10.0	0.29 m	0.95 ft	0.14 m	0.47 ft
f/11.0	0.26 m	0.86 ft	0.13 m	0.43 ft

Of course, you may not want to focus hyperfocally. Playing with Gemini I have pullled out near and far focus for distances based on the lens markings.

Focus Distance: 0.125 m

F-Stop	Near Limit	Far Limit
f/2.0	0.115 m	0.136 m
f/2.4	0.114 m	0.139 m
f/2.8	0.112 m	0.141 m
f/3.3	0.110 m	0.145 m
f/4.0	0.107 m	0.150 m
f/4.8	0.104 m	0.156 m
f/5.6	0.102 m	0.162 m
f/6.7	0.098 m	0.172 m
f/8.0	0.094 m	0.186 m
f/9.5	0.090 m	0.204 m
f/11.0	0.086 m	0.226 m

Focus Distance: 0.15 m

F-Stop	Near Limit	Far Limit
f/2.0	0.136 m	0.167 m
f/2.4	0.134 m	0.171 m
f/2.8	0.131 m	0.175 m
f/3.3	0.129 m	0.180 m
f/4.0	0.125 m	0.188 m
f/4.8	0.121 m	0.197 m
f/5.6	0.117 m	0.208 m
f/6.7	0.112 m	0.225 m
f/8.0	0.107 m	0.249 m
f/9.5	0.102 m	0.283 m
f/11.0	0.097 m	0.327 m

Focus Distance: 0.2 m

F-Stop	Near Limit	Far Limit
f/2.0	0.176 m	0.232 m
f/2.4	0.172 m	0.239 m
f/2.8	0.168 m	0.247 m
f/3.3	0.163 m	0.258 m
f/4.0	0.157 m	0.274 m
f/4.8	0.151 m	0.296 m
f/5.6	0.145 m	0.321 m
f/6.7	0.138 m	0.364 m
f/8.0	0.130 m	0.431 m
f/9.5	0.122 m	0.547 m
f/11.0	0.116 m	0.745 m

Focus Distance: 0.3 m

F-Stop	Near Limit	Far Limit
f/2.0	0.249 m	0.378 m
f/2.4	0.240 m	0.399 m
f/2.8	0.233 m	0.422 m
f/3.3	0.224 m	0.455 m
f/4.0	0.213 m	0.510 m
f/4.8	0.201 m	0.592 m
f/5.6	0.191 m	0.704 m
f/6.7	0.178 m	0.951 m
f/8.0	0.165 m	1.618 m
f/9.5	0.153 m	8.239 m
f/11.0	0.142 m	Infinity

Focus Distance: 0.5 m

F-Stop	Near Limit	Far Limit
f/2.0	0.371 m	0.767 m
f/2.4	0.353 m	0.859 m
f/2.8	0.336 m	0.974 m
f/3.3	0.318 m	1.170 m
f/4.0	0.295 m	1.629 m
f/4.8	0.273 m	2.940 m
f/5.6	0.254 m	14.790 m
f/6.7	0.232 m	Infinity
f/8.0	0.211 m	Infinity
f/9.5	0.191 m	Infinity
f/11.0	0.174 m	Infinity

Focus Distance: 1.0 m

F-Stop	Near Limit	Far Limit
f/2.0	0.588 m	3.356 m
f/2.4	0.543 m	6.311 m
f/2.8	0.505 m	51.991 m
f/3.3	0.464 m	Infinity
f/4.0	0.417 m	Infinity
f/4.8	0.374 m	Infinity
f/5.6	0.339 m	Infinity
f/6.7	0.301 m	Infinity
f/8.0	0.266 m	Infinity
f/9.5	0.234 m	Infinity
f/11.0	0.210 m	Infinity

And, if like me you estimate distance better in feet and inches, here they are – again based on the lens markings for feet:

Focus Distance: 0.41 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	0.38 ft	0.45 ft	0′ 4.6″	0′ 5.4″
f/2.4	0.37 ft	0.46 ft	0′ 4.4″	0′ 5.5″
f/2.8	0.37 ft	0.46 ft	0′ 4.4″	0′ 5.5″
f/3.3	0.36 ft	0.47 ft	0′ 4.3″	0′ 5.6″
f/4.0	0.35 ft	0.49 ft	0′ 4.2″	0′ 5.9″
f/4.8	0.34 ft	0.51 ft	0′ 4.1″	0′ 6.1″
f/5.6	0.33 ft	0.53 ft	0′ 4.0″	0′ 6.4″
f/6.7	0.32 ft	0.57 ft	0′ 3.8″	0′ 6.8″
f/8.0	0.31 ft	0.61 ft	0′ 3.7″	0′ 7.3″
f/9.5	0.30 ft	0.67 ft	0′ 3.6″	0′ 8.0″
f/11.0	0.28 ft	0.74 ft	0′ 3.4″	0′ 8.9″

Focus Distance: 0.5 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	0.45 ft	0.56 ft	0′ 5.4″	0′ 6.7″
f/2.4	0.45 ft	0.57 ft	0′ 5.4″	0′ 6.8″
f/2.8	0.44 ft	0.58 ft	0′ 5.3″	0′ 7.0″
f/3.3	0.43 ft	0.60 ft	0′ 5.2″	0′ 7.2″
f/4.0	0.42 ft	0.63 ft	0′ 5.0″	0′ 7.6″
f/4.8	0.40 ft	0.66 ft	0′ 4.8″	0′ 7.9″
f/5.6	0.39 ft	0.70 ft	0′ 4.7″	0′ 8.4″
f/6.7	0.37 ft	0.76 ft	0′ 4.4″	0′ 9.1″
f/8.0	0.36 ft	0.84 ft	0′ 4.3″	0′ 10.1″
f/9.5	0.34 ft	0.96 ft	0′ 4.1″	0′ 11.5″
f/11.0	0.32 ft	1.11 ft	0′ 3.8″	1′ 1.3″

Focus Distance: 0.6 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	0.53 ft	0.68 ft	0′ 6.4″	0′ 8.2″
f/2.4	0.52 ft	0.70 ft	0′ 6.2″	0′ 8.4″
f/2.8	0.51 ft	0.73 ft	0′ 6.1″	0′ 8.8″
f/3.3	0.50 ft	0.75 ft	0′ 6.0″	0′ 9.0″
f/4.0	0.48 ft	0.80 ft	0′ 5.8″	0′ 9.6″
f/4.8	0.46 ft	0.85 ft	0′ 5.5″	0′ 10.2″
f/5.6	0.45 ft	0.91 ft	0′ 5.4″	0′ 10.9″
f/6.7	0.43 ft	1.02 ft	0′ 5.2″	1′ 0.2″
f/8.0	0.40 ft	1.17 ft	0′ 4.8″	1′ 2.0″
f/9.5	0.38 ft	1.42 ft	0′ 4.6″	1′ 5.0″
f/11.0	0.36 ft	1.80 ft	0′ 4.3″	1′ 9.6″

Focus Distance: 0.8 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	0.69 ft	0.96 ft	0′ 8.3″	0′ 11.5″
f/2.4	0.67 ft	1.00 ft	0′ 8.0″	1′ 0.0″
f/2.8	0.65 ft	1.04 ft	0′ 7.8″	1′ 0.5″
f/3.3	0.63 ft	1.10 ft	0′ 7.6″	1′ 1.2″
f/4.0	0.60 ft	1.20 ft	0′ 7.2″	1′ 2.4″
f/4.8	0.57 ft	1.33 ft	0′ 6.8″	1′ 4.0″
f/5.6	0.55 ft	1.49 ft	0′ 6.6″	1′ 5.9″
f/6.7	0.52 ft	1.79 ft	0′ 6.2″	1′ 9.5″
f/8.0	0.48 ft	2.34 ft	0′ 5.8″	2′ 4.1″
f/9.5	0.45 ft	3.61 ft	0′ 5.4″	3′ 7.3″
f/11.0	0.42 ft	7.84 ft	0′ 5.0″	7′ 10.1″

Focus Distance: 1.0 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	0.83 ft	1.27 ft	0′ 10.0″	1′ 3.2″
f/2.4	0.80 ft	1.34 ft	0′ 9.6″	1′ 4.1″
f/2.8	0.77 ft	1.42 ft	0′ 9.2″	1′ 5.0″
f/3.3	0.74 ft	1.53 ft	0′ 8.9″	1′ 6.4″
f/4.0	0.71 ft	1.72 ft	0′ 8.5″	1′ 8.6″
f/4.8	0.67 ft	2.00 ft	0′ 8.0″	2′ 0.0″
f/5.6	0.63 ft	2.40 ft	0′ 7.6″	2′ 4.8″
f/6.7	0.59 ft	3.29 ft	0′ 7.1″	3′ 3.5″
f/8.0	0.55 ft	5.81 ft	0′ 6.6″	5′ 9.7″
f/9.5	0.51 ft	48.55 ft	0′ 6.1″	48′ 6.6″
f/11.0	0.47 ft	Infinity	0′ 5.6″	Infinity

Focus Distance: 2.0 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	1.40 ft	3.48 ft	1′ 4.8″	3′ 5.8″
f/2.4	1.32 ft	4.09 ft	1′ 3.8″	4′ 1.1″
f/2.8	1.25 ft	4.94 ft	1′ 3.0″	4′ 11.3″
f/3.3	1.18 ft	6.67 ft	1′ 2.2″	6′ 8.0″
f/4.0	1.08 ft	13.10 ft	1′ 1.0″	13′ 1.2″
f/4.8	0.99 ft	Infinity	0′ 11.9″	Infinity
f/5.6	0.92 ft	Infinity	0′ 11.0″	Infinity
f/6.7	0.83 ft	Infinity	0′ 10.0″	Infinity
f/8.0	0.75 ft	Infinity	0′ 9.0″	Infinity
f/9.5	0.67 ft	Infinity	0′ 8.0″	Infinity
f/11.0	0.61 ft	Infinity	0′ 7.3″	Infinity

Focus Distance: 3.0 ft

F-Stop	Near Limit	Far Limit	Near Limit (ft & in)	Far Limit (ft & in)
f/2.0	1.83 ft	8.37 ft	1′ 10.0″	8′ 4.4″
f/2.4	1.70 ft	12.99 ft	1′ 8.4″	12′ 11.9″
f/2.8	1.58 ft	28.90 ft	1′ 7.0″	28′ 10.8″
f/3.3	1.46 ft	Infinity	1′ 5.5″	Infinity
f/4.0	1.32 ft	Infinity	1′ 3.8″	Infinity
f/4.8	1.19 ft	Infinity	1′ 2.3″	Infinity
f/5.6	1.08 ft	Infinity	1′ 1.0″	Infinity
f/6.7	0.96 ft	Infinity	0′ 11.5″	Infinity
f/8.0	0.85 ft	Infinity	0′ 10.2″	Infinity
f/9.5	0.75 ft	Infinity	0′ 9.0″	Infinity
f/11.0	0.67 ft	Infinity	0′ 8.0″	Infinity

Of course, most of us will forget all this and just fudge it. But data is fun, especially if you have embraced your autism in later life, like me.

Of perhaps more use is magnification – so here’s some tables:

Magnification Data (Close Range to 1 Meter)

Focus Distance	Distance (mm)	Magnification ( M )	Reproduction Ratio
0.125 m	125 mm	0.0638x	1:15.7
0.15 m	150 mm	0.0526x	1:19.0
0.2 m	200 mm	0.0390x	1:25.7
0.3 m	300 mm	0.0256x	1:39.0
0.5 m	500 mm	0.0152x	1:65.7
1.0 m	1000 mm	0.0076x	1:132.3

And Just for fun, the data aproaching infinity…

Focus Distance	Distance (mm)	Magnification ( M )	Reproduction Ratio
10 meters	10,000 mm	0.00075x	1:1,332.3
100 meters	100,000 mm	0.000075x	1:13,332.3
1,000 meters (1 km)	1,000,000 mm	0.0000075x	1:133,332.3

If you’ve read this far…

Well done!