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WWII Aerial Lens 5inch f4 ref. No 14A/843
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PostPosted: Thu Jul 30, 2020 9:03 am    Post subject: Reply with quote

jamaeolus wrote:
I was not on the forum for the initial go through on this thread but I find the images exceptional. Especially the early freelens experiments.


I can't wait to get mine mounted. It was a nice surprise when I held it to the camera and looked through the viewfinder. Only close up views, but quite sharp.


Last edited by Sciolist on Thu Jul 30, 2020 9:41 am; edited 1 time in total


PostPosted: Thu Jul 30, 2020 9:39 am    Post subject: Reply with quote

kymarto wrote:
Sciolist wrote:
Has anyone else successfully mounted one of these lenses?


I did without problems, I don't have the lens here, but as I remember it was simply a matter of adding a filter ring adapter on the back to convert to 52mm and then using a Nikon ring to reverse mount a 52mm lens. That goes into a helicoid that attaches to whichever camera you have. I used it on a Nikon D800, and now on my Sony A7RII.

For the record, this lens is the Ross Wide Xpress, and the letters AM stand for Air Ministry. Here are some shots I took with this lens. It has very lovely bokeh if you know how to elicit it, and the only real drawback is that because it is uncoated, it can be very low in contrast if there is any backlight.



Thanks kymarto. Could you please note that I've e:mailed you on your website regarding the lens, but you've answered my question here. It looks like you've gone the same way as Bru3ce, and adapted to the thread on the rear lens block. I don't know why it didn't occur before but I've actually ordered a 58mm-55mm reducer where the 58mm lens hood I am going to use will meet the rear of the lens mounting ring. The portion of the lens body that protrudes rearwards from that ring is 52.85mm diameter. I intend to increase that diameter with masking tape, into which the 58mm lens hood can cut a thread. This will allow me to attach to the body rather than the rear lens block, without making it permanent.

With regard to the lens itself, thanks for the info. Mine is not marked Air Ministry, but I'm not sure if that means it never went to them. All the uses I've found this lens put to, so far, have been related to the air ministry. It seems that markings were rather haphazard during this time, and information on this period of lens making in the UK seems rather poorly documented. According to the Vade Mecum, WWII production of Ross design lenses was shared with other companies, in case one was bombed out, such as the National Optical Company, itself simply a split of Taylor, Taylor, Hobson in order to minimise the effect of any destruction. These lenses were marked NOC or NOCO, but most often, no makers mark at all. *I've read that Ross designs actually made at Ross, have (like mine) a VV prefix before the serial number. The Vade Mecum makes a guess that TTH (NOC or NOCO) was prefixed with UU.

*EDIT: I'm now more of the opinion that the VV prefix indicates a lens made at a Dallmeyer factory.


Last edited by Sciolist on Mon Sep 07, 2020 8:37 pm; edited 1 time in total


PostPosted: Thu Jul 30, 2020 12:12 pm    Post subject: Reply with quote

Mine is also VV. I wouldn't imagine there is much difference as the optical formula is the same. Interestingly, I have a second copy that I bought very cheap, and the rear lens block has a different thread on the two. I guess they had a number of different manufacturers, and possibly different people mounting them.

I'm a Bit concerned a out your mounting idea, since the lens is quite heavy. You will need a fair amount of contact area between your tape and the inside of the hood, if I understand you correctly. If you can find a reverse mounting ring for some thread to some body mount I think it would be more stable. But your way might work as well.

I didn't see any mail. I may have to check my contact form on the website :=(


PostPosted: Thu Jul 30, 2020 2:30 pm    Post subject: Reply with quote

kymarto wrote:
Mine is also VV. I wouldn't imagine there is much difference as the optical formula is the same. Interestingly, I have a second copy that I bought very cheap, and the rear lens block has a different thread on the two. I guess they had a number of different manufacturers, and possibly different people mounting them.

I'm a Bit concerned a out your mounting idea, since the lens is quite heavy. You will need a fair amount of contact area between your tape and the inside of the hood, if I understand you correctly. If you can find a reverse mounting ring for some thread to some body mount I think it would be more stable. But your way might work as well.

I didn't see any mail. I may have to check my contact form on the website :=(


Indeed, the Vade Mecum doesn't mention any optical variance. It does state however that "quality may have varied under war-time conditions". It doesn't state if that is across factories, or across time. Or a combination.

Your mention of a different thread on your second lens brings some clarity for me, as the thread on my rear lens block is an awkward 47.25mm. I actually made an error in saying I am mounting the filter end of a lens hood directly to the Ross lens. I am actually hoping to fit a 58-55 step down ring to the lens, to which the 58mm filter threaded end of the straight sided lens hood will screw into. In effect, I am using it as a short extension tube to get past the lens block, before beginning to reduce to my 42mm helicoid. I am hoping this may give some additional torsional rigidity to the end of the lens hood, but I hear what you say on stability - I'm not totally convinced of my approach myself. I've ordered the parts, so I'll give it a go. The portion of the lens body that I intend to mount to, that which is that portion visible immediately behind the mounting ring, is 5.5mm deep. So really, the amount of 'bearing' will be dictated by the step down ring. I won't know what depth that has until it arrives, but it looks in the pictures less than 5.5mm, for sure.

Don't worry about the e:mail. I only sent it yesterday.

Ian.


PostPosted: Fri Jul 31, 2020 1:16 am    Post subject: Reply with quote

Hi Ian,
I wish I were near my lens so that I could see what I actually did. It was not the rear external thread that varied between my two copies but the internal thread that mounts the rear element group in the barrel. I'm pretty sure that I did manage to at least screw a 48mm filter adapter on far enough to hold it securely. I remember the lens did once drop off, so I'm pretty sure that it was literally crossthreaded rather tenuously. I might have put a bead of epoxy on the connection to stop it from unscrewing. The lens is pretty heavy and I'm a bit dubious. 5mm secured by tape sounds a bit iffy to me.


PostPosted: Fri Jul 31, 2020 4:53 am    Post subject: Reply with quote

kymarto wrote:
Sciolist wrote:
Has anyone else successfully mounted one of these lenses?


I did without problems, I don't have the lens here, but as I remember it was simply a matter of adding a filter ring adapter on the back to convert to 52mm and then using a Nikon ring to reverse mount a 52mm lens. That goes into a helicoid that attaches to whichever camera you have. I used it on a Nikon D800, and now on my Sony A7RII.

For the record, this lens is the Ross Wide Xpress, and the letters AM stand for Air Ministry. Here are some shots I took with this lens. It has very lovely bokeh if you know how to elicit it, and the only real drawback is that because it is uncoated, it can be very low in contrast if there is any backlight.





Funky looking bokeh!










































#4


PostPosted: Fri Jul 31, 2020 9:42 am    Post subject: Reply with quote

kymarto wrote:
Hi Ian,
I wish I were near my lens so that I could see what I actually did. It was not the rear external thread that varied between my two copies but the internal thread that mounts the rear element group in the barrel. I'm pretty sure that I did manage to at least screw a 48mm filter adapter on far enough to hold it securely. I remember the lens did once drop off, so I'm pretty sure that it was literally crossthreaded rather tenuously. I might have put a bead of epoxy on the connection to stop it from unscrewing. The lens is pretty heavy and I'm a bit dubious. 5mm secured by tape sounds a bit iffy to me.


Hi,

Yes, I may end up using something like an epoxy.

I've used decorators tape successfully in the past, but never with so much torsion to be applied by the lens. I suppose at least I may discover its limits. I've found that the layers of paper and glue, when compressed by the action of screwing it on to a female thread, creates a relatively stable male thread in the tape. I've not discovered however, how long this lasts. I'm guessing not forever.

An M42 male thread on an Aka mount brass Schneider. It had lost its mounting ring.




PostPosted: Tue Aug 11, 2020 9:16 am    Post subject: Reply with quote

Well, I have all the bits together.



1. Masking tape.
2. 58-55 step down.
3. 52mm lens hood.
4. 42-52 step up.
5. T2-M42 converter.


PostPosted: Wed Aug 12, 2020 11:49 am    Post subject: Reply with quote

I can't show the new paper thread on the lens as I've managed to lock the step down ring on solid. Doh! Usually the paper 'relaxes' after half an hour and you can screw the ring back and forward. I actually felt it was going to be too tight as I screwed the ring on, but I kept on going, so it's all self inflicted. One too many layers of tape. I'm guessing that wetting the paper will release it, but I'll leave it for now as there's no reason to remove the ring at the moment.

Can you see a tan coloured line between the lens body and the step down ring? That's the paper thread.



Onward...


PostPosted: Wed Aug 12, 2020 4:54 pm    Post subject: Reply with quote

I mounted one of mine in a 200mm lens barrel I stripped the glass & aperture blades out of.

Never used it much, while it's sharp, with 8 air-glass surfaces, contrast and flare are abyssmal.

Another one I mounted in a shutter to use on 5x7. It's okay in that application but I have a Dallmeyer 4 inch that is much better.


PostPosted: Thu Aug 13, 2020 11:21 am    Post subject: Reply with quote

iangreenhalgh1 wrote:
... contrast and flare are abyssmal. ...



Yes, while mocking up various designs of hood to see what works, I came to the conclusion that the lens must have been relatively well recessed into the wings of Spits and Mossies, and anything else. I'm only guessing here and could be completely wrong.

I've just ordered a very tight (58mm internal dia), 40mm deep telephoto style hood. This will not encroach on the image circle being thrown out the back at all. And I suspect I'll be screwing something additional on to that if the shot necessitates. I'll be using an apsc sensor.


PostPosted: Thu Aug 13, 2020 11:30 am    Post subject: Reply with quote

Converted to M42, and waiting for a suitable lens hood to arrive.





The mother of all lens bubbles Smile. About 2 - 2.5mm long measured at the surface.


The white speck at 11 O'clock, above it, is also a big bubble, but I've had to adjust what I regard as big.


PostPosted: Thu Aug 13, 2020 12:08 pm    Post subject: Reply with quote

One of mine has a bubble as well, apparently common in lenses back then I read.

I think they were used with coloured filters in their original role, orange/red probably, that would make a big difference to contrast when used with B+W film.

Nice mounting job, well done. Look forward to seeing your shots with it.

I will dig mine out and try it again, been years since I used it, it's a 4/4 dialyte and in my experience, dialytes are always very sharp lenses that work well at all ranges from infinity to close up.


PostPosted: Thu Aug 13, 2020 1:46 pm    Post subject: Reply with quote

iangreenhalgh1 wrote:
One of mine has a bubble as well, apparently common in lenses back then I read.

I think they were used with coloured filters in their original role, orange/red probably, that would make a big difference to contrast when used with B+W film.

Nice mounting job, well done. Look forward to seeing your shots with it.

I will dig mine out and try it again, been years since I used it, it's a 4/4 dialyte and in my experience, dialytes are always very sharp lenses that work well at all ranges from infinity to close up.


Thank you.

Coloured filters is a good shout. I'd not thought about that. It might account for the thread on the rear lens block? There's also obviously a 55mm(ish) thread on the front, I know.

Is yours a 4/4 dialyte, Ian? That's interesting. I wonder if I've misread the Vade Mecum, which seemed to point to a 6/4 plasmat design. I'll have to go back and check again as I'm only speaking from memory.

Regards,

Ian.


PostPosted: Thu Aug 13, 2020 5:33 pm    Post subject: Reply with quote

It might be a 6/4 plasmat and I'm remembering wrong or mixing it up with the Dallmeyer 5 inch I also have. It's been years and years since I studied the available info, so I may indeed be talking out of my hind end by calling it a dialyte.


PostPosted: Thu Aug 13, 2020 6:00 pm    Post subject: Reply with quote

I just unscrewed the cells from one to check, it is indeed a plasmat. Sorry for my earlier brain fart.


PostPosted: Thu Aug 13, 2020 7:27 pm    Post subject: Reply with quote

iangreenhalgh1 wrote:
I just unscrewed the cells from one to check, it is indeed a plasmat. Sorry for my earlier brain fart.


Thanks for checking.


PostPosted: Mon Sep 07, 2020 10:39 am    Post subject: Reply with quote

Mmmm... well, I don't think a hood is the total solution for these lenses.

Indirect natural light from a large window in an arc of 60 to 90 degrees (two to three o' clock). Somewhere around f/7.0. RAW converted to .jpg.

Sans hood. No pp.


Hood. No pp.


Hood. pp.


There's a lens in there somewhere. Using 50mm of 55mm diameter hood, plus 35mm of 58mm diameter hood.


Lens as fitted to the standard Williamson F24 camera. No more 'hoodage' than I am applying.


The problem could be accounted for due to the lenses being fitted under the wings -


However, they were also be fitted behind the pilot in the upper fuselage. The lens 'hood' was cut away at 45 degrees to allow for a downward angled placement in the fuselage. Therefore, less overall 'hoodage' than I am employing.

From a simple Airfix model for orientation.


Schematic.




Back to the drawing board for me. These lenses were expected to resolve the shape of a car on one square mile of land, from a 5" x 5" negative.

Could angling it down make all the difference? I'll give it a go. Also switching to black and white, and trying Ian's comment on the use of filters.

All images not mine are common usage.