Getting max depth of field from 150mm on 4x5 for close-ups.greenspun.com : LUSENET : Large format photography : One Thread
Being fairly new at this I was wondering if I can get some tips on this as I have a custom made muzzleloading rifle that has exotic wood that I want to photograph. I know some about the "Scheimpflug Rule". Since I only have the 150 lens (hope to get a 90mm soon), I don't have powerful lighting and will use bounce light which means a wider aperture. Any input from anyone appreciated. I use Tri-X. E-mail me. Thanks, RED!
-- Randall "Red" Thomasson (firstname.lastname@example.org), September 22, 2000
Using a larger aperture means you will have to use tilts or swings to maximize your DOF. Position your subject (rifle) so you can take maximum advantage of tilts. Are you using strobe? If so, maybe you can still stop down more and use multiple pops to get your exposure. This works best in a darkened room with the shutter open (on T or B), so you dont need to disturb the camera by recocking the shutter. Just trigger your strobe manually. You can also use a continuous light source and go for a longer exposure. Since you are using B&W, the light temperature isnt much of an issue, so you dont need color compensating filters.
-- Ron Shaw (email@example.com), September 22, 2000.
Red, there is no qick recipe for your problem, you need to read, study and understand the function of aperture, tilt movements and last but certanly not the least the distance which you use for shooting. In other words. Aperture is a way of controlling depth of field, up until certain values the smaller aperture the better , but, beware of diffraction.Knowledgeble Tilt movements in conbination with suitable aperture gives you extreme results, but you have to understand where the focussing plane actually is and what happens when you close your diaphragm. Always try to fill your frame can lead to deep disappointment, sometimes you have to go just a little less close to your subject (smaller picture) and only later crop for maximum results. It isn't difficult but takes time to digest all concepts. There are many books and everyone has its favourites, mine is : Photo Know-how Sinar editions (Carl Koch and Joost Marchesi). Have lots of fun! Andrea Milano w.f.p.a. member
-- andrea milano (firstname.lastname@example.org), September 22, 2000.
Randall: Why not take the rifle outside where there is plenty of light and room to constuct a proper background. Open shade should work well, as will direct sunlight if you can control the reflections. Bright sunlight under a scrim will certainly work. Also, I would try different filters, such as orange, yellow or light red to bring out the grain in what I suspect to be beautiful wood.
A white bedsheet on a frame would make a great scrim for the shot, or you can just drape it over a clothesline and raise the corners on poles. I made some open shade shots of guns at a black powder shoot a few years ago that looked great.
Hope this helps,
-- Doug Paramore (email@example.com), September 22, 2000.
You are using B&W so why not use the aperature that works best and then extend your exposure time to give a good exposure. I often shoot under similar conditions in my home with an ordinary 100 watt bulb. My exposure time ranges from a minute and a half to an hour and a half, whatever is needed. Just a thought.
-- Jeff White (firstname.lastname@example.org), September 22, 2000.
I'm assuming that you will be making detail shots of this subject. If that's the case, there are a couple of things I'd like to point out. First, since depth of field is influenced by subject to lens distance, chances are you will need to use a smaller aperture than you might think in order to keep even a relatively shallow subject in focus. Secondly, a time exposure might be called for in order to use the aperture you require, thus making it necessary to consider three more things! 1. To eliminate the possibility of blur, a rock steady tripod will be necessary as well as a long cable release. 2. You will have to compensate for bellows extension when doing this close-up work, requiring added exposure time. 3. You will need to increase the exposure indicated by your meter and then modified for bellows factor to compensate for the reciprocity departure that film exhibits when making multi-second exposures. The charts indicating what those adjustments are for a particular film are available from the manufacturer. One last thing to keep in mind is that while employing Scheimpflug's rule in doing your set up, be mindful of any portion of the subject that seems to get more out of focus as you experiment with tilts and swings. You don't get something for nothing when adjusting the focus plane! Oh, and I promise this is all I'll add: One reason photographers use monorails for tabletop work is to be able to rack the entire camera forward and backward without changing the distance between front and rear standards. This enables one to focus by moving the entire camera closer to or further from the subject. Without this feature, it's a constant jockying of focus and tripod position to get the subject size correct on the ground glass. I know of some folks who have mounted their field cameras on large focusing racks to accomplish the same thing. I hope this helps you.
-- Robert A. Zeichner (email@example.com), September 23, 2000.
And remember to develope for about 15% less time if your exposure is too much longer than normal for the film you are using. Long exposures for reciprocity departure is always accompanied by decreases in development time. James
-- james (firstname.lastname@example.org), September 23, 2000.
I do want to disagree with James that "all" long exposures need a reduction in development. When I first started doing long exposures I also believed this to be true ( not that James is inexperienced in this matter). I have found that when photographing small areas indoors that I often only have an subject brightness range of only 2 or 3 stops. So I might gain a stop or stop and half in contrast with the long exposure and still give a N+ development. Depends on the situation. If you are controlling the light and aren't starting with a high SBR, then I would say that a reduction may not be needed. Develop for the situation would be my best advise.
-- Jeff White (email@example.com), September 23, 2000.
Along the lines of what Jeff just posted, one of the reasons I prefer T-Max emulsions over others is that they seem to be less prone to building up excessive contrast when shooting long exposures. They are not totally immune from this problem, but only until you get to exposures of around 15 minutes, if memory serves me, do they require some minus development to make the highlights printable without excessive loss of detail.
-- Robert A. Zeichner (firstname.lastname@example.org), September 24, 2000.
Not to dispute anyone but the data sheet for all kodak products say to decrease development by a certain amount so the densities stay within bounds. My shots of white epiphylum cactus flowers the other day indoors with artificial lighting were in the 2-6 minute range, 2.5 stop SBR, TMY and TX sheet film, and when developed to N were dense and contrasty for my original intent. I decreased the development time to 4 mins 15 secs 68* D76 1:1 in hangers. They now print with no manipulation at all. My caution was meant to bring attention the fact that with long exposures the highlight halides are really what you need to watch and adjust for in your development scheme. With the flower set up, the fower petals were a Z7.5 and the deep centers were Z5 so I could safely pull my development without losing any shadow detail deep within the flower. Jeff is right in that not all setups require such vigilance but do beware to use caution and follow the data sheet with long exposures when they get into the minutes range. Make backup exposures if you can. James
-- james (email@example.com), September 24, 2000.