Support our Sponsors, they keep FADU free: AG Photographic The Imaging Warehouse Process Supplies RH Designs Second-hand Darkroom Supplies |
> Bronica SQA lenses |
*** Click here for the FADU 2015/2014 Yearbooks *** |
|
Thread Tools | Search this Thread | Display Modes |
#11
|
|||
|
|||
Hi, CanonJane, it's dismal Jimmy here (see the rest of my reply but if you needed a car to get across to the cottage for a decent shot, it sounds quite a long way away. How far away from the nearest point for a reasonable shot is it?
Given the limited magnification from MF lenses, might it not be better to use say a 500mm cat lens or 300mm with a converter if required on a 35mm camera. If it means serious cropping and enlarging as well to get the cottage big enough then the likes of D100 or T grain low speed film such as TMax 100 in a fine grain developer might help Depending on the distance you might even want to try Adox CMS 20 film which for resolution gets close , some would say, to a 4x5 LF negative. It would be a tripod shot, of course as the speed of CMS is 20 at best in Adox tailored developer and probably nearer 6-10 in most other developers I hope this introduces other possible avenues for the project Mike |
#12
|
||||
|
||||
Thank you guys, certainly lots to think about!
The crofters cottage wasn’t that far away, lack of parking on a single lane road, with difficult terrain and the field of stroppy sheep with lambs meant I couldn’t just walk closer, so it mean a 4 mile detour down the valley and up around the other side. Sent from my iPad using Tapatalk |
#13
|
|||
|
|||
Quote:
Actually nearer to 90mm, or more accurately 93.75mm. That is assuming the prime lens is 80mm. If the prime was a 75mm which is half of 150mm the magnification would equal to a 100mm lens on a 35mm. Last edited by John King; 4th July 2021 at 05:07 PM. |
#14
|
|||
|
|||
The diameter of 6x6 is 8.485.
The diameter of 2.4x3.6 is 4.32. (4.32 divided by 8.485) times 150 is a little over 76. |
#15
|
|||
|
|||
Here are a few pages from an old SQA / SQAi Bronica brochure.
I will try and put the whole catalogue of accessories etc. on the appropriate section of the forum tomorrow. http://www.film-and-darkroom-user.or...1&d=1625432516 http://www.film-and-darkroom-user.or...1&d=1625432516 http://www.film-and-darkroom-user.or...1&d=1625432516 http://www.film-and-darkroom-user.or...1&d=1625432516 There is at photo at the top of one of the pages showing the comparative image size from the different focal length lenses. Bit more tomorrow. Cheers.
__________________
It will all be over by Christmas. |
#16
|
|||
|
|||
Quote:
To get the same with a Bronica prime 80mm to get the same degree of magnification a lens would have to be 160mm, but as the comparison is with a 150mm lens the reduction in size of the image is just below that in proportion of the two 35mm lenses and not as small as you suggest. This was part of the syllabus taught when I was on a course for my City and Guilds exam in 1963. The film size does not come it the equation especially considering the formats are a different shape. Turn a 120mm neg into a similar proportion to a 35mm neg you don't get a larger or smaller image, it just means more is cut off. Last edited by John King; 4th July 2021 at 10:15 PM. |
#17
|
||||
|
||||
Thank you all!
Sent from my iPhone using Tapatalk |
#18
|
||||
|
||||
Here are my calculations for the 35mm film format equivalent of 150mm focal length lens on 6x6 in millimetres.
Film diagonal 35mm (24x36) = 43.2mm Film diagonal 6x6 (56×56) = 79.2mm 43.2 ÷ 79.2 = 0.545mm 0.545 x 150 = 81.75mm However, gven that the standard 50mm focal length lens of 35mm is 15% longer than the film format diagonal, the equivalent in 6x6 would be a 94mm lens. 81.75 + 15% = 94mm In conclusion, scientifically, I don't see how lens focal length equivalents can be calculated without taking the film format into consideration. And optically, the difference between the 35mm standard 50 lens vs 150mm lens is a multiple factor of x3. While the equivalent 6x6 standard 80mm lens vs 150mm is only a multiple factor of x1.9. Therefore, the impact of a 150mm lens on 6x6 could be visually underwhelming in comparison to a 150mm on 35mm film format. A lens of 250 would perhaps be more satisfying in this respect.
__________________
MartyNL “Reaching a creative state of mind thru positive action is considered preferable to waiting for inspiration.” - Minor White, 1950 |
#19
|
|||
|
|||
It seems from the above posts that there are several ways to calculate the equivalence of 35mm and 120 lenses. Here's another.
Measure the diagonals of each negative. Multiply these by the double-indirect-thorcus of the primary integer. Then divide these figures by the number of times it rained during your last holiday in Wales. If you now have minus numbers, multiply them by the number of times your car was broken into if your Welsh holiday was in Blaenau Festiniog. This should do the trick. Alternatively, if, like me, you don't like maths, you could do the following. Take a 6 x 6 Bronica SQ with standard 80mm lens, and a 35mm Olympus OM1 with standard 50mm lens. From the same position, use them both in turn to frame the same subject. Do they both encompass the same width of view? When I tried this the 80m lens had a slightly narrower width of view. I concluded that a 75mm lens would have the saame width of view, and would therefore be the equivalent of a 50mm on a 35mm camera. So - a nice easy ratio of 2:3 Alan |
#20
|
|||
|
|||
I wish I could combine irony and the serious point as well as you do, Alan!
Anyway, differences aside, Jane's best bet is clearly to find a way of trying the options out practically rather than theoretically. [But I would certainly take seriously the last three lines of Marty's post] |
Support our Sponsors, they keep FADU free: AG Photographic The Imaging Warehouse Process Supplies RH Designs Second-hand Darkroom Supplies |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Bronica SQ | CanonJane | Cameras - medium format | 64 | 22nd May 2020 08:32 PM |
Bronica SQ-A with two lenses | wojtek | Sale or Wanted | 1 | 3rd July 2018 09:39 PM |
FS: Bronica SQ-Ai kit | paulc | Sale or Wanted | 12 | 2nd May 2016 09:52 PM |
Wanted: Bronica SQ-Ai lenses | Jakecb | Sale or Wanted | 0 | 9th May 2015 04:58 PM |
Wanted: bronica gs1 wlf | stevep | Cameras - medium format | 1 | 26th April 2013 08:20 AM |