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A.3. (a) what you think about a camera that could defocus only the background in a portrait shot.
A.4. (b) Which automatically sets the Aperture for a proper depth of field by detecting the faces at various points
in a group shot.
A.5. such maneuvers are treated,only as additional or subsidiary features,falls within the scope of flash selection with
it's more capability on image enhancement, manipulation etc.
A.6. The following short writeup is especially aimed at expert's attention,better skip this page or just take it with
a gulp,if you are a novice.
A.7. Lets see how such a situation could be tackled with flash selection
A.8. flash selection –it deem to be come a photographic practice which basically involves with exposure of
two frames taken with different apertures. For the first one the ambient light is made use of, where the measured exposure
level may leads to determine an exposure at a nominal 1/60th.sec @ f:11 suggestive of a bright sunny day. The adjacent frame
is made to receive an exposure of 1/1000th.sec @ f:2.8 if the is not practical(when such a wide aperture is not provided on
the lens or availability of ambient lighting is not high enough)....hence one could opt for, 1/500th.sec @ f:4 utilizing
light from a flash (thrown at from camera position) in addition to ambient light.
A.9. But these norms are not so rigid ones, as you may note later, in different part of this site... explained as how
the routine of flash-selection could also be executed by maintaining the same aperture (in contrast to procedure explained
above).Again it suggests how flexible the technique is. But a criterion strictly,obeyed here is to see to that all these frames
have received, basically the same amount of exposure or approximately.
A.10. now you could easily guess ,here is a situation where these two frames could be compared against each other, for
distribution of density variation and a change of image-definition infocus between the foreground VS the background by a
measure of values called, the C.O.C (circle of confusion). These values forms the ingredients for the formation of two strong
&staunch logics that are more analytical, along with are some more logics not mentioned in this site. These could be further
extended to what is called as fuzzy logics that could behave like a method called interpolation,to arrive at a in-betweenness
of focusing with the available image data of foreground and the background. In fact these routine of capturing two or more
frames can be made into a regularized (embedded) process or by means of wading through a maze of menus to invoke,as you would
find in a latest digital camera...be it in photography , cinematography,videography.
A.11. To answer some basic question that may strikes you.
A.12. Question : what if the ambient light is low for a 1/1000th.sec or 1/500th.sec photography?
Answer: We know we can change over to a higher ISO and simultaneously to use a slower shutter speed that the flash-selection
can easily cope with.
A.13. Question :What if the asking aperture is high due to a flash ?
Answer: Reduce it with the power ratio of flash or mount a ND filter or a diffuser over the flash-head etc., but not taking
the flash unit backwards in-order to increase the distance between the subject and flash , so that essentially the divergent
property of light is not disturbed.
A.14. These are, two such simple question and easily clarified. I cite these basic ones to show how such a kind of preparation
is needed, that is so vital for handling a photographic shoot in a proper manner,or in a still more still more better way,...
a shoot that would insist on doing professionally. Such a preparation a single word can it be called... a 'premeditation'
if the very wording is correct.
A.15. The word suggests a disciplined & methodical way of making correction at best and collecting all the information
that could be acquired of an image at the shoot itself ..it suggests you don't go bare-hand to proceed for image editing /enhancement
(with the required information is lacking) as in the case for eg., improving sharpness , contrast , saturation etc.,
The so called doctrine of premeditated shoot with Flash-Selection:
A.16. It would be amply clear, that the flash selection is such a tool abiding to the philosophy of a preplanned shoot,
although the procedure could be executed in an automated mode .It is not a lenient technique , where taking an advantage for
not properly lighting or a recklessness of not at all caring about the lighting... is encouraged, in the first place . But
Flash selection has it's forgiveness of insufficient lighting in one way, that it could amplify the small amount of light
you could afford (to throw at) in a given situation.
A.17. For those who compares, this with HDR(high dynamic range), I wish to clarify the following,Please note it is
not specific to Photoshop exclusively, but inclusive a trend probably pursued by other image-editing soft-wares ...is meant
here.
A.18. There need not arise a comparison because HDR is functionally a compression tool , whereas the Flash-selection
is basically a selection tool. But with the means how it is done ...that is.
A.19. Probably it's how you may perceive or you're given an impression when viewed through one facet of the feature
of HDR , but going deeper through other facets of HDR [which already borrows my ideas of multiple exposure] , and when it
combines with yet another newly introduced compositing and blending option ,I reserve some of my comments for later update.
The HDR is an attempt to addresses the very perennial problem of Dynamic-range of image sensor/captures could cope with [like
the FUJI image sensor with pixels of sensitivity two different kind], by a procedure of aggregation, compression and by transposition
of Image Data. So it essentially exhibit the characteristics of a compression tool isn't it?.
A.20. With flash-selection, the Dynamic range is only one such,among the various tasks & it's capacity, that it could
able to execute. you would find this one as an all-rounder, from it's basic nature of a non intrusive selection tool and in
controlling the level of sharpness, contrast, saturation, the pattern of lighting, to amplify the input of lighting so and
soforth.
A.21. I would say that HDR is the very first, in it's attempt compared to every other tools, in an image editing-software
package, such as in photoshop falling in-line with the concept of premeditation. Because it demands some kind of pre-planning
,a routine of procedure you should comply with at the time of shoot itself that was never before. Yes for the first time in
an Image-editing environ either in Adobe Photoshop just any others who have developed /adopts the concept of HDR. The routine
or the pre-planning is about, a procedure of taking a numerous frames of the same subject with different level of exposure
that would encompass/encourage, the gathering of as much image detail from shadow to the highlight that you could gather at
the stage of shoot itself.
A.22. It is also probably the first time we have had departed from a regular practice as we usually would do, to salvage
an image assuming that the imperfection in terms of contrast, the tonal range, lighting etc., could be corrected by the image
editing procedures as it has encouraged by soft-ware themselves (even though those vital image information is laking or absent
all together).
A.23. Please observe that if an image is over-exposed to gain more of shadow detail as the HDR demands. It may give rise
to lens-flare that would drastically reduce the saturation in the image of a given object. The actual solution could be,
(to input some more light into the shadow area, rather than opening up the aperture.
A.24. I would completely agree with, there are situation where the addition of light will not have any impact / influence
over the prevailing lighting thus a Flash-selection may become useless eg., Landscapes, with which the HDR could cope with.
A.25. With HDR – all those numerous frames are taken without a change in lighting.
A.26. More information on multi-exposure and HDR related please read at topic under multi exposure_Photohifx.... later
in my web-site
A.27. OR a site like http://www.naturescape.net which is dedicated to subject on HDR.
A.28. Visiting this site (with its depiction of fantastic images,helps apart from serving the purpose to define HDR),
you could learn the nuances of HDR photography and How multiple-exposure couldn't be handled casually but with a feather touch
handling in it's execution,it also gives you a fair chance to make you visualise then how potential the FLASH_SELECTION could
be, many more with the claims you are about to read in the ensuing pages ....not as a tool taking care of Dynamic range but
a whole bunch of capabilities.
A.29. but this is very too early a stage before you could finish reading to have an understanding on what is flash-selection
could do.
A.30. Last but not the least,the conceptual of flash-selection was stressing on points of multi-exposure and high-sync
flash that is propounded by me at a much earlier time. Please note more details of warning against the acts of plagiarisms
Copy Cats at photohifx part 1 under para F:31
A.31. These are only skeletal information before you could plunge deep into the technique of flash-selection which begins
with page titled Casual-photo
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