تويت
التصوير الفوتوغرافي الحديث
تجهم الصور ..
ما هي العدسات للشراء ..
العناية بالعدسات وعلاجها ..
WHAT LENSES TO BUY
You will find , after gaining some experience in the use of lenses , that you often have to effect a compromise in choosing a lens . You cannot have all the desirable features you want combined in one lens . What you gain in one direction , you lose in another , and so you must govern your choice by the kind of work you plan to do .
For the general run of commercial photography , exterior and interior shots , and copying , you do not need extreme speed . For home portraiture , especially when making pictures of babies and young children , speed in a lens is very desirable .
Just as a general suggestion , suppose you are planning to do commercial work of all kinds and that you also want to be equipped for taking portraits either in your own studio or in the homes of your clients . It is suggested that you provide yourself with two lenses to begin with .
If you are planning to use a 5 x 7 camera for general commercial photography , you will find a lens of medium focal length , 7½ or 8 inches , most useful . If you are planning to use the 5 x 7 camera for portraits and you want to make pictures showing only the head and shoulders , you will need a longer - focus lens in order to get the head large enough to fill the 5 x 7 film properly without having to place the camera very close to your subject . It is often possible to pick up an old portrait lens with a focal length of , say , 12 to 14 inches , which would have sufficient speed to make it an excellent lens for head - and - shoulder portraiture . A lens of this type for portraits and another lens of medium - focal length for general work would be about all you would need to begin with . Of course , you could use a convertible lens and this would provide the medium - focus lens for general work and a longer focus lens for portraiture , but the drawback to this would be that the single components of a convertible lens are a good deal slower than the complete lens .
If you already own a smaller camera of good quality with a fine lens , you can use it for professional work . A great many professional photographers use small films for making the negatives and print from them by projection . Another way in which you could obviate the need for buying a rather expensive long - focus lens for head and shoulder portraits , if you use the 5 x 7 camera , would be to use a sliding masking device in the back of the camera and thus make two exposures on one 5 x 7 film . By making two half - size negatives , each measuring about 3½ x on one 5 x 7 film , you can use the medium focus 7½ or 8 inch lens for portraits and you will be able to get the head large enough to fill the 3½ x 5 film area without having to place the camera too close to the subject .
THE CARE AND TREATMENT OF LENSES
A high - grade lens requires extremely careful handling . A lens will not produce good results unless it is in good condition , and to keep it in good condition , it must be properly cared for . Dirt or grease from finger prints is a frequent cause of blurred and hazy pictures . Always keep your lens clean .
The greatest possible care must be exercised in cleaning a lens , since optical glass is comparatively soft , and careless rubbing may easily scratch it . The best thing to use for cleaning lenses is the special lens tissue sold by optical and camera stores . Even this special tissue must be used lightly and carefully . Any surface dust must be either blown or brushed away , or it may scratch the glass in the subsequent rubbing . Blowing with an ear syringe is best .
When not in use , keep the lens boxed , with the glass surfaces protected with lens caps at both ends , and store in a dry , cool place . Lenses in constant use should be cleaned regularly and examined for scratches . This is the only way you can be sure your lenses are in perfect condition to produce the best results . When using lenses outdoors , especially in winter or during a rain , watch for condensation on the glass caused by sudden changes in temperature .
تجهم الصور ..
ما هي العدسات للشراء ..
العناية بالعدسات وعلاجها ..
WHAT LENSES TO BUY
You will find , after gaining some experience in the use of lenses , that you often have to effect a compromise in choosing a lens . You cannot have all the desirable features you want combined in one lens . What you gain in one direction , you lose in another , and so you must govern your choice by the kind of work you plan to do .
For the general run of commercial photography , exterior and interior shots , and copying , you do not need extreme speed . For home portraiture , especially when making pictures of babies and young children , speed in a lens is very desirable .
Just as a general suggestion , suppose you are planning to do commercial work of all kinds and that you also want to be equipped for taking portraits either in your own studio or in the homes of your clients . It is suggested that you provide yourself with two lenses to begin with .
If you are planning to use a 5 x 7 camera for general commercial photography , you will find a lens of medium focal length , 7½ or 8 inches , most useful . If you are planning to use the 5 x 7 camera for portraits and you want to make pictures showing only the head and shoulders , you will need a longer - focus lens in order to get the head large enough to fill the 5 x 7 film properly without having to place the camera very close to your subject . It is often possible to pick up an old portrait lens with a focal length of , say , 12 to 14 inches , which would have sufficient speed to make it an excellent lens for head - and - shoulder portraiture . A lens of this type for portraits and another lens of medium - focal length for general work would be about all you would need to begin with . Of course , you could use a convertible lens and this would provide the medium - focus lens for general work and a longer focus lens for portraiture , but the drawback to this would be that the single components of a convertible lens are a good deal slower than the complete lens .
If you already own a smaller camera of good quality with a fine lens , you can use it for professional work . A great many professional photographers use small films for making the negatives and print from them by projection . Another way in which you could obviate the need for buying a rather expensive long - focus lens for head and shoulder portraits , if you use the 5 x 7 camera , would be to use a sliding masking device in the back of the camera and thus make two exposures on one 5 x 7 film . By making two half - size negatives , each measuring about 3½ x on one 5 x 7 film , you can use the medium focus 7½ or 8 inch lens for portraits and you will be able to get the head large enough to fill the 3½ x 5 film area without having to place the camera too close to the subject .
THE CARE AND TREATMENT OF LENSES
A high - grade lens requires extremely careful handling . A lens will not produce good results unless it is in good condition , and to keep it in good condition , it must be properly cared for . Dirt or grease from finger prints is a frequent cause of blurred and hazy pictures . Always keep your lens clean .
The greatest possible care must be exercised in cleaning a lens , since optical glass is comparatively soft , and careless rubbing may easily scratch it . The best thing to use for cleaning lenses is the special lens tissue sold by optical and camera stores . Even this special tissue must be used lightly and carefully . Any surface dust must be either blown or brushed away , or it may scratch the glass in the subsequent rubbing . Blowing with an ear syringe is best .
When not in use , keep the lens boxed , with the glass surfaces protected with lens caps at both ends , and store in a dry , cool place . Lenses in constant use should be cleaned regularly and examined for scratches . This is the only way you can be sure your lenses are in perfect condition to produce the best results . When using lenses outdoors , especially in winter or during a rain , watch for condensation on the glass caused by sudden changes in temperature .
تعليق