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02-26-2019, 10:19 AM   #1
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Medium format needs a lot more light?

While reading about larger camera format, this article The Light Eater: The Biggest Challenge of Large Format Portraiture | Fstoppers caught my attention. I though of getting some clarification and feedback from people having experience with medium format: how practical is the use of a medium format format compared to 24x36 ? Is it truly difficult to use for common use cases? Thank for sharing your thought from experience. I'd be very interested.

02-26-2019, 10:48 AM   #2
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I found the article a bit muddled. I use a Pentax 645z, A K-1, and sometimes a 645Nii or Hasselblad. I also have a Cambo 4x5" film camera.
It's all about the lens and area of film / sensor you are trying to illuminate. The 645z is trivial to step up to from a FF 35mm Pentax - the faster lenses tend to be f/2.8 instead of f/1.4, so that means you need to respect the light meter ;-) and probably add more light. I use the same 540FGZII on both the K1 and 645Z, as well as Godox AD400 and AD600Pro.

Larger lens diameter = more light gathering power = usually heavier. Plus ts harder to get a flat field on the film plane corner-to-corner.

The old 4x5 and 8x10 flim cameras tended to have smaller, slower lenses than the optical wonders we have today. Plus you are trying to cover a heck of a lot more surface area with photons at the focal plane.
02-26-2019, 10:53 AM   #3
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Yes and no. In the KB-World 2.8 an higher is normal. In the medium format only some optics have 2.8 most of them are 4.0 ore less. Therefore you need more light fully open.
If you come down to the same aperture, there isn't any difference in the light.
02-26-2019, 10:56 AM - 1 Like   #4
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I wonder which question I should answer first - let's start with amount of light. MF lenses do have longer focal lengths in order to preserve proper field of view, for instance 'standard' for 6x7 is either 90 or 127 mm. Using 1/f rule, it means slowest shutter speed of 1/90 or 1/120 s. Moreover. these lenses are slow - f/1.8 for Mamiya 645 is the fastest one, the rest for this system offers something like f/2.4 at best. Lenses for 67 are even slower, typically around 3.5 or 4. When you take bellows into account, like in Mamiya RB/RZ, additional 0.5 or 1 stop of light can be lost. Is MF practical? Well, it depends on how you are going to use it, and which MF we talk about. In general 645 SLR can be considered heavy and beefed up version of 24x36. Mamiya RB 67 is like a heavy shoebox but it is capable camera. 6x9 rangefinder (i.e. Fuji GSW) is large, but light. I haven't had Pentax 67 so I cannot tell anything about it.

02-26-2019, 11:30 AM   #5
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QuoteOriginally posted by pentageek Quote
MF lenses do have longer focal lengths in order to preserve proper field of view, for instance 'standard' for 6x7 is either 90 or 127 mm. Using 1/f rule, it means slowest shutter speed of 1/90 or 1/120 s.
It's good that you mention about the shutter speed and reciprocity because I was asking myself the question whether I could use a slower shutter speed to compensate for the smaller aperture needed for the depth of field. I remember when I used apsc (Pentax K3) , some people had issues with the pixel density and we agreed that on apsc we should use a shutter speed = 1.5 x 1 / FL (for example: FL = 70mm on apsc, the minimum shutter speed would be around 1/100th sec. for apsc). So if I use the same idea for medium format, it would need that I can use a shutter speed slower than the 1/FL reciprocity used for full frame. For example, for full frame the shutter speed would be 1/100th s. for 100mm FL lens on full frame, and the shutter speed would still be 1/100th sec. with a 130mm FL lens on medium format 645z. But I don't know to what extent that would still work.

So, to be short, I don't know if the slower lens can be compensated by a slower shutter speed when using the 35mm equivalent focal length for the reciprocity rule.
02-26-2019, 11:31 AM - 3 Likes   #6
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FWIW, I use the same light meter for my meterless 35mm cameras as for 4x5 large format. Any concerns about "total light" and light gathering ability of available lenses are baseless unless one is doing astrophotography.

That aside, there is the matter of DOF being more precious with the larger format such that f/5.6 is a fast lens on 4x5 and even that may be hard to manage without using the camera's movements. Medium format is not a whole lot better. Consider the traditional Pentax lineup of lenses for 645 and 6x7; yes, f/2.8 is the norm for a "fast" lens of moderate focal length and it is not a matter of physical size. Faster apertures are unusable. It might be noted that ISO 400 films are very popular for natural light photography with larger format due to the freedom to use shorter exposure times and the happy coincidence that the larger format "eats" grain due to less magnification being needed for enlargements.

I noted the use of camera movements. They exist, at least partially, to allow for adjustment of the focus plane to help compensate for low DOF. The article mentions bellows extension. Yes, that reduces effective lens speed, but the case is overstated for all but tight head shots and table-top work. The rule of thumb is no compensation at less than 50% extension (~1/2 stop, 1:2 "macro") from infinity.

Now, in regards to medium format...Have we ever read about the so-called "medium format look"? Generally that means some form of splendid subject-to-background isolation. Surprise! That look comes at a price in terms of shutter speed and ISO, though it is not as steep as with large format. Examples with EXIF from the medium format area of this site as well as a survey on Flickr might provide a reasonable sampling of where the limits are. I can provide a few examples from 6x7 negatives. Sorry, if I took notes regarding aperture, I could not find them...

Chamonix 045N-2 (view camera), 6x7, 150mm, unknown aperture, hand-held meter with no bellows compensation or movements used, Ektar 100.




Chamonix 045N-2 (view camera), 6x7, 150mm, unknown aperture, hand-held meter with no bellows compensation, significant use of swing and tilt to adjust focus plane, Ektar 100.



It is unlikely that this shot could have been made without use of camera movements.


Chamonix 045N-2 (view camera), 6x7, 150mm, unknown aperture, hand-held meter with no bellows compensation or movements used, Acros 100.




Chamonix 045N-2 (view camera), Token 4x5" for comparison, 150mm, unknown aperture, hand-held meter with no bellows compensation, swing and tilt used to adjust focus plane, Arista.EDU Ultra 100.



Yes, movements were required for this shot. IIRC, I was using f/22 or thereabouts. Note that the trees in the background are OOF.


Chamonix 045N-2 (view camera), Another token 4x5" for comparison, 90mm, unknown aperture, hand-held meter with no bellows compensation, swing and tilt used to adjust focus plane, Arista.EDU Ultra 100.



Yes, even with a wide angle, DOF is an issue at moderate distances (the near foreground was about 4' distant). I was able to use a longer exposure here (~2s) and due to dim light, I was probably no wider than f/22, but still had to use both swings and tilts (front and back) to provide adequate near-far focus.


Steve

Last edited by stevebrot; 02-26-2019 at 12:04 PM. Reason: Added notation regarding camera used
02-26-2019, 11:54 AM   #7
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QuoteOriginally posted by stevebrot Quote
Yes, even with a wide angle, DOF is an issue at moderate distances (the near foreground was about 4' distant. I was able to use a longer exposure here (~2s) and due to dim light, I was probably no wider than f/22, but still had to use both swings and tilts (front and back) to provide adequate near-far focus.
So in all of these cases presented here, you had to use a tripod either to allow tilt/shift or simply cope with the slow shutter speed?
02-26-2019, 12:01 PM   #8
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QuoteOriginally posted by biz-engineer Quote
So in all of these cases presented here, you had to use a tripod either to allow tilt/shift or simply cope with the slow shutter speed?
My bad...all were done with my Chamonix 4x5 view camera, a tripod-dependent thing. The examples were chosen to show where the limits might be for common shooting. There are better examples on this site and on Flickr. Since the linked article in the original post was specific to large format, these might be pertinent.

Using tilt and shift for Scheimpflug is an on-tripod experience regardless of camera used.* Walk-around hand-held use for general shooting is possible and common with medium format cameras made for that purpose, but requires good technique. With any luck, user @Rense might check in. He does street photography with a Pentax 6x7 using the waist-level finder !





Steve

* Rough adjustment is eyeballed on the ground-glass followed by fine adjustment with a magnifying loupe.


Last edited by stevebrot; 02-26-2019 at 01:22 PM.
02-26-2019, 12:22 PM - 1 Like   #9
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Medium format isn't much harder than 24x36 (full frame), unless you simply must have f/1.4 or f/1.2 lenses. FStoppers use such lenses since they're the only cool things to use and you simply must be cool (long sigh.) The point of the article is large format has noticeably smaller working apertures than cool full frame kit so in the same situation you'll need more powerful lights when shooting under artificial light. That's all.
02-26-2019, 12:29 PM - 1 Like   #10
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QuoteOriginally posted by biz-engineer Quote
So, to be short, I don't know if the slower lens can be compensated by a slower shutter speed when using the 35mm equivalent focal length for the reciprocity rule.
There are at least two approaches

1. 'traditional' 1/f rule - ignores format
2. 1/f rule with crop factor - this is the scenario where you could use slower shutter. Basically it means that 1/50s should be fine for every 'standard' lens regardless the format.

To shed a light on the latter: 1/50s should (on average) yield sharp images in following configurations: 35mm / APS-C, 50mm / Full Frame, and 90mm / 6x7, in short with 'standard' lens for given format. In reality, it depends on photographer and equipment used - I use option 1, but this is my personal choice, and of course YMMV. Weight of the camera may affect minimal shutter speed, but again this is matter of personal preference, albeit most people claim that heavier cameras are more stable. The weight may differ significantly even within same class of MF - for example Mamiya RB 67 is around 50% heavier than Pentax 67.
02-26-2019, 02:18 PM - 1 Like   #11
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QuoteOriginally posted by stevebrot Quote
My bad...all were done with my Chamonix 4x5 view camera, a tripod-dependent thing. The examples were chosen to show where the limits might be for common shooting. There are better examples on this site and on Flickr. Since the linked article in the original post was specific to large format, these might be pertinent.

Using tilt and shift for Scheimpflug is an on-tripod experience regardless of camera used.* Walk-around hand-held use for general shooting is possible and common with medium format cameras made for that purpose, but requires good technique. With any luck, user @Rense might check in. He does street photography with a Pentax 6x7 using the waist-level finder !





Steve

* Rough adjustment is eyeballed on the ground-glass followed by fine adjustment with a magnifying loupe.
I did, yes, but that is already some time ago.... time to dust-off the whole thing and get it rolling again....
Nice setup you show here!~!!!!!
02-26-2019, 02:24 PM - 2 Likes   #12
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The short answer is yes. Use a tripod or add light, or be prepared to push the ISO. Don't forget the 645Z doesn't have IBIS either.

There's no such thing as a free lunch.
02-26-2019, 03:18 PM   #13
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QuoteOriginally posted by biz-engineer Quote
I though of getting some clarification and feedback from people having experience with medium format: how practical is the use of a medium format format compared to 24x36 ? Is it truly difficult to use for common use cases?
With 645 film, my default ISO is usually 400 unless I am with a tripod or want shallow depth-of-field using something like Ektar 100 or Delta 100. But I also prefer shooting wide to normal, and usually not movement unless I want to blur it, so again, it's not that big of an impediment for me as I can shoot with slower shutter speeds and larger apertures.

With digital medium format, I think it's less of an issue because of the quality at much higher ISO ratings.

If you're used to FF or APS-C or even 35mm film, then yes, it does feel limiting, but the tradeoff is worth it for what I shoot and how I display/exhibit my work.

Also note: There is a big difference between the large format 4x5+ in the article and medium format.

Last edited by Alex645; 02-26-2019 at 03:28 PM.
02-26-2019, 10:42 PM   #14
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Dont forget that the Fuji G(S)W series has leaf shutters. I managed to handhold a GW690 III down to 1/15 without blur, although usually 1/30 was the slowest I used IIRC.
02-26-2019, 11:10 PM   #15
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Medium format often requires more skill to use successfully, such as with hand-held metering, of which being just knowledgeable in one method will not carry you through all situations. Also, MF cameras are viewed more as the craftsman's tools with their inherent lack of automation and gimmicky floss (e.g. Hasselblad 500CM and varients, then look at other marques which can often be seen to have more automation but still allowing complete control) which for many decades went hand-in-hand with the creative vision of the person using the camera, driven by the mind's eye, rather than what the camera wants to do, and how! For a lot of work, to get the very best quality from MF, a tripod is preferred over handheld, together with refined technique (handling and lenswork).


My use of 35mm spanned the period 1977 to 2009, continuously producing work from transparency to the Ilfochrome Classic media (of which I am a Master Printer, for some time allied with ChromaColour in Adelaide/South Australia). I would not bother going back to 35mm and producing IC prints when vastly better quality baseline imaging and printing is achieved far easier with MF, and also large format. It is much easier to meter precisely with MF and LF than the at times clumsiness of 35mm, but I will say modern meters are more than capable, but not a substitute for astute judgement and observation.

---------- Post added 27th Feb 2019 at 05:13 PM ----------

QuoteOriginally posted by stevebrot Quote
Chamonix 4x5 view camera, a tripod-dependent thing.

I witnessed one of these beauties come crashing down onto coastal rocks a few years ago. The owner was ...DEVASTATED. Turned his back, along came a gust of wind and...Chammo was no more...
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