tjkoko
Senior Member
I remember having an Edmund's catalog back in the 1960s. Please tell me about the discoloring, was the lens frame made of those materials?
-
Welcome to the new forums! Please read this first. For known issues we are working to resolve, click here.
Large format, an elusive concept
- Thread starter JimKasson
- Start date
In the olden days, some lens elements contained radioactive materials, chosen for their optical properties. Thorium oxide has high refractivity and low dispersion. The browning is caused by the element being exposed to its own radiation.
Modern lenses don't use those isotopes.
just Tony
Senior Member
Interestingly, the yellowing can be reversed via a great deal of UV irradiation. After burning out a 100 uv-led flashlight I continued with good old sunlight. However I still didn’t get very far and the 100 “dimples” from the first round of effort were still faintly present.
Forums for vintage Pentax lenses are rife with these stories.
tjkoko
Senior Member
Nolo comprende!
just Tony
Senior Member
Those powerful LED flashlights have 100 individual LEDs in a disc about 5 cm across. I laid it directly onto the lens so the array of LEDs made an array of bleaching spots on the lens.
mplkn
Forum Enthusiast
"ULF!" is what you say as you lift it onto the tripod....Among those who still use sheet film, larger than 8x10 is conventionally referred to as Ultra Large Format (ULF).
I always considered my 8x10 Arca Swiss as a studio-only camera. I can't imagine doing the field work that Michael Smith used to do with his 8x20 camera."ULF!" is what you say as you lift it onto the tripod....Among those who still use sheet film, larger than 8x10 is conventionally referred to as Ultra Large Format (ULF).
mplkn
Forum Enthusiast
I'm blessed to own a Ritter 8x10, handmade from hardwoods and carbon fiber rods by a master craftsman in Vermont:
https://www.lg4mat.net/LFcamera.html
The Ritter weighs next to nothing in large format terms, but by the time you add a bag with some lenses, a Gossen Spotmaster, a focus cloth, a bag with a half dozen film holders, and, oh yes, the tripod, it really adds up. I've taken to using a modified jogging stroller to bring it along. The results are stunning, but it takes planning, commitment and conscious intent. My 4x5 is a Toyo VX125, itself a svelte beauty in the large format world, but the same issues apply.
It's not the cameras, you see, it's what I call (ahem) the Ancillary Adams! (ducks behind desk)
This is why the GFX series represents such a miraculous development to me, even now, after several years of use. Sure, it's still a handful, but if you leave the lens bag in the car and take just what you need, then you can just grab the thing and walk. Astonishing.
I've said it before, but really, working with the GFX files feels less like working with the scans of medium format film from my Nikon scanner, and more like working with the scans of 4x5 film from my Imacon Precision II.
And you can just grab it and go.
Amazing.
https://www.lg4mat.net/LFcamera.html
The Ritter weighs next to nothing in large format terms, but by the time you add a bag with some lenses, a Gossen Spotmaster, a focus cloth, a bag with a half dozen film holders, and, oh yes, the tripod, it really adds up. I've taken to using a modified jogging stroller to bring it along. The results are stunning, but it takes planning, commitment and conscious intent. My 4x5 is a Toyo VX125, itself a svelte beauty in the large format world, but the same issues apply.
It's not the cameras, you see, it's what I call (ahem) the Ancillary Adams! (ducks behind desk)
This is why the GFX series represents such a miraculous development to me, even now, after several years of use. Sure, it's still a handful, but if you leave the lens bag in the car and take just what you need, then you can just grab the thing and walk. Astonishing.
I've said it before, but really, working with the GFX files feels less like working with the scans of medium format film from my Nikon scanner, and more like working with the scans of 4x5 film from my Imacon Precision II.
And you can just grab it and go.
Amazing.
Last edited:
mplkn
Forum Enthusiast
Yes, absolutely. I keep the large format stuff because I just can't bear to part with it, and because on certain days, it's how you want to spend some time.
There really is something special that can happen under the focus cloth. It's quiet, serene, and conducive to concentration; it clears the mind. You don't grab a shot, you build it.
I recommend the experience to any who might be curious about it.
But that's for the process. The outcome, the results we can achieve with medium format can rival large format in strictly technical terms.
Fortunately, or unfortunately, it takes more than that to make something worth printing at large scale. An excellent large print of a mediocre shot is just an embarrassment.
There really is something special that can happen under the focus cloth. It's quiet, serene, and conducive to concentration; it clears the mind. You don't grab a shot, you build it.
I recommend the experience to any who might be curious about it.
But that's for the process. The outcome, the results we can achieve with medium format can rival large format in strictly technical terms.
Fortunately, or unfortunately, it takes more than that to make something worth printing at large scale. An excellent large print of a mediocre shot is just an embarrassment.
Last edited:
themediocreenthusiast
Senior Member
Do you "feel" 8x10 large format film would have better resolution than 44x33 MF Digital? I'm amateur still learning about MF both digital/ film and just happened to read some old blogs from Fuji archives. As explained and quote below - it seems like 24mp aps sensor already exceeded the resolution of 645 film.
So where are we with 8x10 or larger yesterday's terminologies or are we already getting better images with GFX 50x or 100x?
------------
GFX Technologies #3
https://fujifilm-x.com/en-sg/stories/gfx-technologies-3/
" Let’s be clear. It is unfair to compare GF Lenses directly with existing medium format lenses. The image quality of conventional medium format system was largely dependent on the size of imager. The granularity (= resolution) of the film remains the same even if the size changes, so bigger the film, the better the picture quality will be. However, imager has changed from film to CMOS sensor, and the resolution per unit area has improved.
The 24MP APS sensor used for X Mount now has exceeded the resolution of 645 film."
"It is also important to note that the lens is optimally designed for the imager. The G Mount sensor has resolving power of that 4×5 large format with the mere size of 43.8×32.9mm. Rather than cropping the center of large format lenses, better images are delivered by optimal lens design for the image circle."
Last edited:
These kinds of comparisons give different results depending on how you define the word resolution. If it’s extinction resolution, 8x10 film wins over the Sony 100 MP 33x44mm sensor.
Erik Kaffehr
Veteran Member
Hi,
I don't think resolution is very relevant, especially not in the digital era. The more important qualities may be 'acutance' and smoothness of the image.
With film, there was always a huge variation between films. But, another important factor was the lens.
According to my experience, Velvia with my Pentax 67 delivered about 20 MP of usable resolution. That was comparable to my 24 MP full frame gear, but the 24 MP digital image is smoother.
Back in 2006 quite a few photographers switched from 4"x5" film to Phase One P45 backs, finding the P45 a good replacement for the 4"x5" film.
Now, replace Velvia with T-MAX 100 and there may be much better resolution, when combined with an excellent lens.
Another way to see it may be that digital formats have better signal noise ratio, so they may be better in extracting low contrast detail, while film may be able to define finer high contrast detail that a low resolution sensor may not be able to resolve, leading to aliasing artifacts.
In a sense, I would say that image resolution is sort of a 'red herring'. Image quality is a multidimensional volume that is poorly described with a single scalar value.
Best regards
Erik
darinb
Senior Member
Indeed. Often overlooked is the very real improvement in the perception of image quality (when comparing LF to digital) when you don't have to carry or deal with heavy, awkward film holders.
I know I sure see it.
--Darin
Mikhail Kartashov
Well-known member
- Messages
- 146
- Reaction score
- 30
ProfHankD
Veteran Member
Edmund is primarily targeting industrial cameras. For those FF is HUGE. Most are C-mount webcams. Put bluntly, FF would be a huge sensor for a beefed-up webcam, wouldn't it?
Give this time. I still believe actual large-format sensors are not that far off.
Keyboard shortcuts
- f
- Forum