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View Full Version : Getting ready for my first picture, some questions on exposure and such



Merijn
7-Aug-2016, 09:51
Hey guys, I postponed by DIY camera project to get some more experience with LF photography first. I've managed to find a really nice Sinar F1 setup with a Prontor-Press shutter and MC Rodenstock Geronar 210mm F6.8 lens. (pic of the camera: http://i.imgur.com/Wg4lNtx.png) Right now I'm at the point where all my parcels have come in the mail. I've got my camera, film, chemicals etc. and I'm just waiting on the changing bag and mod54 to really get started. For my first pictures I elected to use some economical fomapan 100 film.

Anyway that also means I'm currently working out the practical problems like getting good exposure. I'm seeing a lot of mentions online on using a DSLR to do the metering. I assume this essentially means matching the film's ISO and the camera's aperture. I have some questions about this.


How much does the lens used on the DSLR affect things? I was under the impression that a long lens requires more light than a wide one and thus affects the suggested shutter speed when metering with a DSLR. I only use primes for my digital camera so I don't have one exactly matching the focal length of the Geronar 210. Nor am I entirely sure what the equivalent of the geronar would be for my DSLR (Canon 7D).
Is it really as simple as spot metering the most important areas of the composition and deriving a suitably weighted average?


Along the same lines I have some questions about developing the film. I found the developing charts on Digital Truth and they look quite helpful. But for the purposes of learning I'd like to experiment a little. In order to get a better feel for what makes a good exposure, would it be smarter to make several pictures while bracketing the shutter speed or would it be more educational to take several pictures with the same camera settings but play with longer and shorter development times?

Finally, I'll probably start with some still lives so I don't spend anyone else's time with my experiments. But my real interest lies in portrait photography. I figure the main challenge there will be shutter speed. The obvious solution seemed faster film but googling around a bit it seemed that solution wasn't as obvious at it seemed. The fomapan 400 film seemed to get considerably more unfavourable reactions compared to the fomapan 100.

My other thought is studio lighting. I have a number of Canon speedlite 580s and accompanying umbrellas and softboxes. I noticed the shutter has a synch attachment. Are there any unique challenges regarding the use of those speedlites with my 4x5 camera?

Your replies are appreciated as is any unsolicited advice you might have.

Jac@stafford.net
7-Aug-2016, 10:26
An F-Stop is an F-Stop, regardless of focal length, type of lens. You could use your DSLR with the ISO set to the same as your LF film. However, from your description it seems you are going to shoot in studio-like settings, and/or at modest distances where, imo, a handheld light + flash meter with an incident dome would work better. Forget the DSLR.

Regarding exposure and development, keep it simple: start with the given ISO, meter properly, develop film normally. Work from there. Nail shadow detail, determine if you can see highlight texture. With controlled lighting such as several flashes, it is much more likely that you can get a good negative by varying light rather than introducing too many variables at once.

Your shutter probably has a standard pc flash connector. It likely has two or three synch settings, M, X and perhaps V. Use X. Your flash units probably have a slave sensor. Look into that rather than mucking with a bunch of cords.

Don't over think it. Yet.

Peter De Smidt
7-Aug-2016, 10:47
The speed settings on a dslr are not necessarily equivalent to film speeds. Digital cameras, at least mine, act much faster than film. Moreover, you have a huge range of settings on the digital camera that will effect the results. Testing would be in order. As start, I would up the contrast on the dslr. So for instance, I shot a studio scene with my D600 set at 100 sensitivity level, and I exposed a 4x5 sheet of film rated at 100 at the same aperture with a film camera. The dslr had plenty of shadow detail. The film had very little. (The film tested at EI 100 in standard testing.)

drew.saunders
7-Aug-2016, 11:00
If you can, get your shutter speeds tested for accuracy. It won't matter much if you're using flash, but if your shutter speeds are off by a half stop or more (and some very likely will be), you can be in for a lot of frustration. The top speeds are more likely to be off than the slower speeds.

Your lens is a simple one with 3 glass elements. If you were to use a zoom on your DSLR with 20 or so elements, then you might have a noticeable difference in how much light is getting through the two lenses. You can look up the difference between f-stop and t-stop if you want. If you're using a prime, then it shouldn't make a difference, certainly not more than the shot-to-shot variance in the accuracy of your shutter.

If you want to use flash, absolutely get a flash meter. You'll be using your flashes in manual mode, so a flash meter will really help. There are some flash-only handheld meters, but a good combined regular/flash meter will serve you better going forward. Used ones are fine.

You can use wireless remotes to trigger your flashes, and many wireless remotes will take a PC cord. I don't know if there's a TTL compatible wireless remote for your Canon flash, but it might be worth getting just so you can use it with both your DSLR and LF camera. If the wireless remote for the Canon flashes doesn't have a PC port, you can use one of these: http://mpex.com/lumopro-universal-hot-shoe-adapter-ii.html to connect the PC port on the lens to the remote. You'll need a short PC to mini cable to go from the lens to the adapter, then anything you put on the hot shoe part of the adapter will be fired by the lens. I've used one for my LF camera. I'm fortunate in that my Ebony has a cold shoe on the front standard, so I don't have to figure out where to put the adapter.

Merijn
7-Aug-2016, 11:10
An F-Stop is an F-Stop, regardless of focal length, type of lens. You could use your DSLR with the ISO set to the same as your LF film. However, from your description it seems you are going to shoot in studio-like settings, and/or at modest distances where, imo, a handheld light + flash meter with an incident dome would work better.

Regarding exposure and development, keep it simple: start with the given ISO, meter properly, develop film normally. Work from there. Nail shadow detail, determine if you can see highlight texture. With controlled lighting such as several flashes, it is much more likely that you can get a good negative by varying light rather than introducing too many variables at once.

Your shutter probably has a standard pc flash connector. It likely has two or three synch settings, M, X and perhaps V. Use X. Your flash units probably have a slave sensor. Look into that rather than mucking with a bunch of cords.

Don't over think it. Yet.

I'm starting with some still life pictures in the garden just to get the hang of operating the camera and developing film before adding an extra factor.

My flash units do have a slave sensor but I'm not entirely sure how that would work. On my DSLR I use some radio remotes that simply use the TTL system. You're suggesting I use a sync cord to connect the first flash and then slave the other units to that one? I see no switch on the shutter to switch between M, X or V. All I'm seeing is a simple PC sync port. Does that mean it's using the X system?

Pere Casals
7-Aug-2016, 11:36
The speed settings on a dslr are not necessarily equivalent to film speeds. Digital cameras, at least mine, act much faster than film. Moreover, you have a huge range of settings on the digital camera that will effect the results. Testing would be in order. As start, I would up the contrast on the dslr. So for instance, I shot a studio scene with my D600 set at 100 sensitivity level, and I exposed a 4x5 sheet of film rated at 100 at the same aperture with a film camera. The dslr had plenty of shadow detail. The film had very little. (The film tested at EI 100 in standard testing.)


Hello Peter,

I compared the photometer reading of my film Nikon F5 with the Nikon D610 and D800, it gives the same reading in spot mode, with matricial mode it can work different. Nikon F5 knows the type of film by DX code and it exposes depending on the latitude constrains of the film. Latitude is coded in the DX contacts. See Reading DX codes https://en.wikipedia.org/wiki/DX_encoding.

Also aperture is a geometric parameter, and different lenses can deliver slight different readings with same aperture because number of groups or coatings, specially when comparing primes to zooms.


Regards.

Jac@stafford.net
7-Aug-2016, 12:01
[...] Also aperture is a geometric parameter, and different lenses can deliver slight different readings with same aperture because number of groups or coatings, specially when comparing primes to zooms.

May I inject some sanity? First, it is true that some applications, for example cine photography, use T-Stops, but they require such precision to match different lenses to a scene, and so-forth.

Here we are practicing still photography with shutters that are rarely precise and the difference between each speed on a LF shutter can vary more than T-stops vs F-stops. If I'm not crazy, then others likely work the same - we know what shutter speeds work for us and use them, and with a prized lens with a whacked out shutter, we find the speed(s) that work for us and ignore the rest of the speed settings. We adapt.

OP - don't worry about the aperture. Take it at face value. It's more likely with a DSLR there are variations of in-camera processing, some of it secret proprietary, that you cannot have with a LF camera. So, just forget the DSLR.

Pere Casals
7-Aug-2016, 12:28
May I inject some sanity?

Here we are practicing still photography with shutters that are rarely precise and the difference between each speed on a LF shutter can vary more than T-stops vs F-stops. If I'm not crazy, then others likely work the same - we know what shutter speeds work for us and use them, and with a prized lens with a whacked out shutter, we find the speed(s) that work for us and ignore the rest of the speed settings. We adapt.

OP - don't worry about the aperture. Take it at face value. It's more likely with a DSLR there are variations of in-camera processing that you cannot have with a LF camera. So, just forget the DSLR.


Many use a DSLR or a SLR as a photometer for a view camera. In my case I use and adapter and I place a Nikon F5 in the back of the view camera (without lens in the F5) and so I meter TTL, Through The Lens. In this way I can expose LF film in the same way I do with an SLR, some films are a bit different from roll to sheet, but Velvia works the same.

I've measured the speeds of my shutters with a photodiode and oscilloscope to know how I'm exposing. With negative film there is more room for errors, I've one shots Velvia/Provia 8x10 there is no room for looseness, a mistake is painful.

It depends on what one do, in my case I'm preparing to shot Velvia 8x10, and I feel I need very precise exposures.

Pere Casals
7-Aug-2016, 12:34
http://i.imgur.com/Wg4lNtx.png

What a nice thing !!!

I also own a Sinar, mine is a Norma.


Here you have a tutorial "Perfect Exposures with Large Format Cameras"

from the "stellar" Ken Rockwell :)

http://www.kenrockwell.com/tech/exposure-large-format.htm

http://www.kenrockwell.com/tech/meters-digicam.htm


I agree with what he says, things can be more complicated but I think that this it is a very good introduction.

Regards

Jim Jones
7-Aug-2016, 16:59
. . . My flash units do have a slave sensor but I'm not entirely sure how that would work. On my DSLR I use some radio remotes that simply use the TTL system. You're suggesting I use a sync cord to connect the first flash and then slave the other units to that one? I see no switch on the shutter to switch between M, X or V. All I'm seeing is a simple PC sync port. Does that mean it's using the X system?

Yes, with built-in slaves you only need to use a sync cord on one flash and slave the others. As for the lack of switch between M. X, or V, those options were more common long ago when flash bulbs were being replaced by electronic flashes. With modern shutters and in the absence of that switch, the sync is probably X. It's easy enough to check out. When doing so, a reduced flash output is advised.

Pere Casals
8-Aug-2016, 04:00
Is it really as simple as spot metering the most important areas of the composition and deriving a suitably weighted average?




To learn how a film works I'd suggest to use first a film SLR. With 135 you can bracket exposures to see the difference. With LF grain will be smaller and quality higher, but tonality should match.

With negative film, if a doubt, better to overexpose a bit. With slides (Provia) do the counter.


If you explore your field of view with a spot meter (with a DSLR or SLR) you'll find the good expositions for shadows and illuminated areas.

For portrait (caucasian skin) you can expose in a way that face area illuminated by key light are at +1 or +1.5.

In general important shadow areas can be at -2, but -3 it is not very good, depending on used film. Also important illuminated areas can be at +2, but at +3 it is worse.


Also it depends on the developer you use, a full speed developer like Xtol (or D-76) wants the standard exposure, other developers need in general 1/3 stop to 1 stop more.


With sheets you can make a special development for the particular conditions of each shot, this is very powerful:


You can place shadows at -2 and lights at +5, then you expose for the shadows at -2, but lights will be burnt. Then you develop for the lights to compensate that overexposure "making a N-3 development", with a shorter development time like if a 400 ISO film was shot at ISO 50. In this way you control a scene with 7 stops of dynamic range.


This is the basic method of the Zone System, beyond this there are additional techniques: special developers, stand development, and a long list of etc, and BTZS.


To measure with a DSLR with spot mode just use a prime lens like Nikon 50mm f/1.8D, if you use a zoom the reading won't match by perhaps 1/2 stop, because zooms have a lot glass groups and deliver less light to the DSLR sensor with same indicated aperture. A prime 50mm lens will match more the exposure of a LF lens.


Remember that when you focus near with a view camera you have to compensate exposure. As you extend bellows the projected light cone has a wider base, projected circle is bigger, and so photons are spread in a larger surface, so you need to correct for it, increasing exposure.


A final advice, at beginning just load a cheap Nikon F80 with same film you are using for sheets and make a bracketing -1 ,+1 then you can learn what you like the more.


Regards.

D. Bryant
10-Aug-2016, 15:16
Pere,

What large format camera(s) do you use?

Pere Casals
11-Aug-2016, 05:33
Pere,

What large format camera(s) do you use?

Camera is not the most important but, answering you, I've a Sinar Norma 4x5 that I love a lot.

And then I use CAMBO, the 4x5, the 5x7 and the 8x10.

This is the 8x10 and the 4x5 attached to learn macro https://www.flickr.com/photos/125592977@N05/27823423611/in/dateposted-public/