Fotodiox extension tube question

[annamaria]

With that much extension, life is going to be a pain. Try using JUST the 14mm tube, or JUST the 28mm tube for most subjects. With a longer focal length, like say 150 to 300mm, there will not be a lot of need for a huge amount of extension. Try to use as little extension as possible, and use lens focal lengths beginning around 45mm or 50mm, and longer. AVOID using short focal lengths with such long extension tubes as 7mm or 14 or 28mm; using even a 7mm tube with a short lens will cause the point of focus to move literally INSIDE of the lens barrel--and no, I am not kidding.

I had not noticed the rest of your comment. So that answers my previous question.

 

[Derrel]

With that much extension, life is going to be a pain. Try using JUST the 14mm tube, or JUST the 28mm tube for most subjects. With a longer focal length, like say 150 to 300mm, there will not be a lot of need for a huge amount of extension. Try to use as little extension as possible, and use settings of from 50mm and longer.

Thanks Derrell I will definitely give it a try. I have the 18-55 and 55-300 lens. I guess I should use the 55-300 right ?

You can use the 18-55 at its longer end; I knew you had an 18-55,and wanted to let you know that at shorter lengths, even a short "normal length" tube will cause the point of focus to move inside of the lens barrel; Nikon used to make some **exceptionally thin** "K-rings" that were designed to get around that issue, but those are discontinued.

Keep in mind...close focusing and lens extension will make the wide-open lens aperture settings admit LESS light, so keep that in mind...you want a smallish f/stop for at least a few millimeters of depth of field. The 18-55 is f/3.5~5.6; I thought the 55-300 was f/3.5~5.6, so the two lenses will have DIFFERENT effective f/stop values at 55mm setting.

 

[annamaria]

You can use the 18-55 at its longer end; I knew you had an 18-55,and wanted to let you know that at shorter lengths, even a short "normal length" tube will cause the point of focus to move inside of the lens barrel; Nikon used to make some **exceptionally thin** "K-rings" that were designed to get around that issue, but those are discontinued. Keep in mind...close focusing and lens extension will make the wide-open lens aperture settings admit LESS light, so keep that in mind...you want a smallish f/stop for at least a few millimeters of depth of field. The 18-55 is f/3.5~5.6; I thought the 55-300 was f/3.5~5.6, so the two lenses will have DIFFERENT effective f/stop values at 55mm setting.

Thanks again appreciated very much. I will keep all those factors in mind. Love these forums everyone is so helpful.