Bracketing exposures

[Jim Chinn]

I had a recent discussion with a friend about bracketing exposures. We both agree that some people can get it spot on every time with a good meter and familiarization with materials. But I find that bracketing seems to be inversely proportional to the cost of the format, at least for me. i will bracket with 35mm, especially if I am making test shots for a future return to the site with an LF camera. 4x5 I will usually make at least one more shot with one extra stop exposure, and for 8x10 I will also grit my teeth and shoot an extra shot.

With 11x14 I almost never do unless it is something that I feel might make a good alternative process neg and will expose for that or I may make a duplicate exposure if I think I may want to use dyes or on the film masks.

Of course, if it is something of once in a lifetime quality, I will make one extra shot of the one exposure I believe is correct.

The funny thing is, I am almost always spot on with my first calculation and so I waste fim. Any suggestions on how I can improve my trust in my own abilities? And also, what are others attitudes towards bracketing exposures.

 

[lee]

I feel for you Jim. I do the same thing. I have tried to limit this expensive compulsion but as of yet no joy. I rationalize it as helping my prevent industrial accidents in the darkroom.


lee\c

 

[Aggie]

..

 

[Jorge]

Learn to use the BTZS properly and you will never look back. When I used the zone system I had the same problem, I was never sure if my exposures were good and was forced to make at least two shots. Since I started with the BTZS every single negs has been on the spot unless I made a mistake. I gotta tell you I could kick myself for not learning it sooner, all that film I wasted.

 

[lee]

Jorge,
If I don't make a mistake my exposures are dead on using the zone system. I don't think I need to start over now.


lee\c

 

[Jorge]

Jorge,
If I don't make a mistake my exposures are dead on using the zone system. I don't think I need to start over now.


lee\c

Well, my response was for Jim. If you are happy the way you are doing it all the more power to you.

 

[David A. Goldfarb]

I sometimes bracket color slide film, since there can be a range of about 2/3 stop where the exposures might all be "correct" but the emphasis or emotional quality will be different.

I don't bracket B&W, but if there is a scene where I'm a bit unsure as to how much contrast will really look good at the printing stage, I'll expose a second sheet and keep it in reserve, though in the end the first development time is usually right, and the reserve sheet serves as a safety sheet in case the first one gets scratched or some distracting element walks into one of the versions.

 

[MikeK]

With 35mm I bracket, but with large format I take my time I meter the scene from the highest value to the lowest value and set my exposure depending on the contrast range of the scene and the shadow detail I want. I then mark the holder/packet for N-, normal and very rarely N+ devlopment. Success is good enough for me not to change my ways.

I did change my developing strategy when I migrated to a Jobo CPE2+

- Mike

 

[Tom Duffy]

a lot of other things can botch a negative besides exposure. since I'm an imprecise weekend photographer, I usually take 2 identical and slightly overexposed (sheets in B&W. based on a shadow spotmeter reading, and use the second sheet to bracket development in case I get it wrong the first time.
color transparencies are entirely different. there I'll rate an EI 100 speed film at 80 and take an straight incident reading or spotmeter the brightest value in the scene and place that at "zone" 7.5. As David said, with transparencies, the nuanced difference with a small bracket arount correct exposure is usually important.

 

[Jim Chinn]

Yes, I think in the next year I am going to explore BTZS. As I work with the larger formats I want to be more precise about tailoring negatives for alternative processes and contact printing.

 

[Lex Jenkins]

I shoot only 35mm and medium format. The former in particular tends to encourage bracketing, whether in b&w or color. I also tend to segregate my shooting styles and subject matter according to the format. With 35mm I tend to shoot rapidly, casually and make lots of insurance shots. The subjects are often people.

I bracket with impunity when shooting for Diafine since adjusted development is impossible. This is essential to my nighttime photography. As long as there's time to bracket I'll do so.

Most of the time with MF work, tho', (generally using developers other than Diafine) my approach is more deliberate and I seldom make more than one exposure of a subject. If I do I'll often recompose as well. I'll spotmeter, think in terms of N+/-, in effect doing everything I don't normally do when using 35mm.

 

[lee]

Jorge,
If I don't make a mistake my exposures are dead on using the zone system. I don't think I need to start over now.


lee\c

Well, my response was for Jim. If you are happy the way you are doing it all the more power to you.

I just wanted to tweek your nose senor all in fun.

lee\c

 

[JohnArs]

Hi

What means BTZS I'm german speaking and I have no idea what thad means!

 

[Jorge]

Beyond The Zone System. ....an aternative method for exposure measurement and testing than the zone system.

You can check phil's web site at:


www.btzs.org

 

[Ole]

In LF I don't bracket exposure - I bracket developing. I (usually) shoot both sides of the holder at exactly the same setting. When I get home, I unload all holders and develop evey second negative in the stack (I have a vague idea of which order they're in). If the first negative is good, I develop the second one the same way - just in case one of them is scratched or fingerprinted or something. If not, I look closely at the first one to decide what to do with no. 2.

Sometimes I'll use the second negative for experimenting with new mixes. If I know the first one is good in developer A, I will try it in developer B. It is interesting to see the differences in tonality and "structure" between different developers...

 

[Drew B.]

bracketing & digital question

After a while, and after bracketing (both + & -) you start seeing the same spaces (oh, I'm an architectural photographer) and the same types of light. The negs soon are all good and you'll stop bracketing. (maybe I should start going over and under two stops!) After a while, you get tired of taking 30 images of 10 spaces, and say the heck with it.

Now, what I really need to know, since I'm not that knowledgable with digital images, is what to do with the digital image to make it appropriate for uploading to the web. How do i squeeze a 250 meg file into 150K for this site and what happens to the quality?

Drew

 

[mark]

After a while, and after bracketing (both + & -) you start seeing the same spaces (oh, I'm an architectural photographer) and the same types of light. The negs soon are all good and you'll stop bracketing. (maybe I should start going over and under two stops!) After a while, you get tired of taking 30 images of 10 spaces, and say the heck with it.

Now, what I really need to know, since I'm not that knowledgable with digital images, is what to do with the digital image to make it appropriate for uploading to the web. How do i squeeze a 250 meg file into 150K for this site and what happens to the quality?

Drew

Definately the wrong site for this question. You will have a better chance of an answer if you go to www.photo.net or someother digital oriented site.

 

[johnnywalker]

Definately the wrong site for this question. You will have a better chance of an answer if you go to www.photo.net or someother digital oriented site.

Are you sure he's not asking how to get a big analogue picture down to a postable size? If so it's a reasonable question I think.

 

[Ed Sukach]

Sounds like a reasonable question for the submission of images to APUG. I personally use (don't laugh, gang) Corel's Photo House, the Graphics program included in WordPerfect's System 8. One can set the magnification to "pixels on each side, maintaining aspect ratio", and visually see the total size of the file. I'm sure there must be many other Graphic programs that have the ability of this "dinosaur".

 

[Nicole]

I wasn't aware of 'bracketing' until recently - where have I been! Photographing children a lot of the time - I find it challenging enough trying to get them with the one shot rather than trying for 3.
All 3 images would be different compositions anyway depending on the speed and energy levels of the child, their mood, .... Lots of fun. I prejudge and preplan as much as I can and in the end do my best and hope for the best.

 

[David Brown]

I have been known to bracket when I was just unsure of the exposure.

MY problem (YMMV) is remembering to meter carefully - especially with chrome. I tend to let the TTL meters in the SLRs do their job. This is fine, until there's a big expanse of sky that overwhelms the foreground, which gets underexposed (but the clouds are pretty :rolleyes: ).

If I would just meter lower, lock exposure, ...

Bottom line, whatever works. But experience will teach you!

Cheers.

David

 

[rbarker]

Although bracketing doesn't work well with active subjects, as Nicole mentioned, I tend to look at the practice as being insurance. Not just insurance that I have the exposure nailed, but insurance against other factors that might damage the film. Other than with local subjects that can be conveniently re-shot, film is probably the least expensive element in making the image.

So, with LF B&W, I'll often make a backup shot at the same exposure, and then bracket plus and minus by a stop. For color, the bracketing is 1/3 stop. The trick is to keep the film organized so the backup sheets are not processed at the same time as the primary film.

Similarly, when shooting color on important projects, I'll separate the film into smaller batches, and have it processed on different days. That way, if the lab has a problem, the whole project isn't lost.

 

[Flotsam]

I think that bracketing is especially important when shooting tranparency films. Holding those highlights from going blank is so important and sometimes a scene just looks better a half a stop darker than even the most carefully metered exposure.

 

[John McCallum]

My 35mm camera could be set to automatically bracket 3 consecutive exposures by a user config'd amount. This combined with the fast motor drive meant I could make a significant contribution to the continuing viability of profitable film manufacture. I've never bothered to learn how to use the feature.

OTOH with the LF my preference is to follow Ole's approach. If the negative could be significant, I like to expose 2-3 sheets the same and develop them differently.

 

[Bruce Osgood]

It seems to me bracketing exposures is only useful if you process your own sheet film

I have shot 35mm color roll film bracketed and taken it to local lab for 'normal' processing and the stock prints returned all look the same. There is no evidence of my bracketing in 36 images. This means to me that perhaps the 'lab' compensates for over/under exposure in their processing of normal.?

So I feel bracketing is only effective in the development stage of sheet film where processing compensation can be applied one neg at a time.