Topic: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

I have been searching for one of these since I saw a set of images from an f2.7 version in a photographic magazine. I had to wait many years, as they are rarely available. The lens has variable aperture, down to f16, but no focusing mechanism. Essentially, it is a bellows lens.

Just to make thing worse, the thread is M32 x 1.0mm. I have many adapters but I had nothing for this. So I contacted raf.camera dealer on Ebay who, after some discussion, made one for me. It is a thread converter, inner, female, thread M32, outer, male, thread M42. It arrived this morning.

I have had just a quickie session with it. Would it form an image and would it cover the sensor? On m4/3 both were OK. Straight onto the camera, via the new adapter and an M42-m4;/3 adapter, the FOV was 4mm wide at a working distance of ca 15mm. I tried a few shots at f16, with triple flash, hand-held. At that working distance the main problem was not to block the off-camera flash with the camera.

The subjects were those I have posted elsewere on the site, recently, shot through my Schneider HM40 setup. There are two slime moulds and the goblet-shaped mushroom with "eyelashes".

I am very pleased with the results. Whether they are up to those from the HM40, I suspect not, remains to be seen. I originally wanted the lens for lower magnifications that show here.

I want to see what the lens will do at higher magnifications. One option is to use tubes on the camera flange to set shorter extensions. The other, if it covers the frame, is to use my full frame A7R.

The images are uncropped.

Harold

http://www.fredmiranda.com/forum/ufiles/08/1382308.jpg?ts=1480082585

http://www.fredmiranda.com/forum/ufiles/09/1382309.jpg?ts=1480082585

http://www.fredmiranda.com/forum/ufiles/10/1382310.jpg?ts=1480082585

http://www.fredmiranda.com/forum/ufiles/11/1382311.jpg?ts=1480082585

http://www.fredmiranda.com/forum/ufiles/12/1382312.jpg?ts=1480082585

Last edited by e6filmuser (2016-11-30 21:17:53)

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

I have some shots on the full frame A7R. I will process and post today.

Harold

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

Here are the images from the A7R full frame. The sun was low and there was some shadow, so I rally struggled at f16 to see anything at all. So the focus of them all could be better. These, as the first set, were all by (twin this time) TTL flash with the camera in manual mode.

The images have been process exactly the same as the first set (except there was less noise to remove). They have not been cropped. The most important result, for my purposes anyway, is that the frame is filled. Without the m4/3 crop factor the DOF is halved.

I am content that it is worth persisting with the evaluation of this lens for my choice of photographic subjects. It is only about the same size as a low power microscope objective so it could easily be added to a set of lenses.

Harold

http://www.fredmiranda.com/forum/ufiles/36/1382336.jpg

http://www.fredmiranda.com/forum/ufiles/37/1382337.jpg

http://www.fredmiranda.com/forum/ufiles/38/1382338.jpg

http://www.fredmiranda.com/forum/ufiles/39/1382339.jpg

http://www.fredmiranda.com/forum/ufiles/40/1382340.jpg

Last edited by e6filmuser (2016-11-25 16:33:38)

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

Taylor Hobson Cooke Anastigmat 12.5cm f2.5: Shorter Extension

This time, I used only the A7R full frame so there is no crop factor to complicate aperture/DOF. I found a way of temporarily mounting the lens ca 10mm closer to the sensor than in the previous experiment, 35mm rather than 45mm. This would get the lens closer to its design registration distance, which I believe to be a bit shorter than for NEX lenses. This gave a FOV ca 10mm wide (previously 8mm).

Unlike the previous session, I had bright sunlight to help with framing and focusing. I wanted to use f11 but this gave no images with useful DOF. So I took some at f16. Even with this, the shots of the pink, candyfloss-like Arcyria were mostly OOF.

This image is of a rather concave surface with crowded Trichia spore sacs on it. Those nearest the lens have matured, split open and expanded, showing fine detail. I took two non-consecutive shots which make a reasonable crosseye stereo pair (slightly cropped at right side).

For those who would say "why bother to do this with an old, legacy film lens" I say "why not?". I suspect it is a 16mm film lens.

Harold

http://www.fredmiranda.com/forum/ufiles/92/1384492.jpg

http://www.fredmiranda.com/forum/ufiles/93/1384493.jpg

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

As has been pointed out to me elsewhere, I have muddled the focal length with that of another macro lens. This one is 12.5mm not 12.5cm.

Harold

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

e6filmuser wrote:

I have muddled the focal length with that of another macro lens. This one is 12.5mm not 12.5cm.

I was quite surprised and had no idea about the scale of the pictures, till I saw you used a tiny film lens!
I like the attemps to use the lens.

Last edited by Minolfan (2016-12-02 10:34:50)

Re: Taylor Taylor Hobson Cooke Anastigmat 12.5mm f2.5: First Session

Minolfan wrote:
e6filmuser wrote:

I have muddled the focal length with that of another macro lens. This one is 12.5mm not 12.5cm.

I was quite surprised and had no idea about the scale of the pictures, till I saw you used a tiny film lens!
I like the attemps to use the lens.

Thanks.

I have done extensive searches and cannot absolutely confirm it, but I think this is a cine lens. I have seen reports that this series of lenses had very high definition and a very flat field. They were used on what are reputed to be the very best (amateur) cine cameras of the day. I can find nothing about the format/image circle issue, this one covering at least "full format" 35mm. None of this would be about macro use.

I have now combined two further rings to get the lens firmly attached 10mm closer to the sensor than for this set with a FOV ca 9.5mm wide.

Harold