Want the same focal length

[gr8five]

Im moving from dx to ff and looking at past photos to get an idea what facal length I use the most. When I look at the ifo on a picture from my old d90 with a Tamrom 18/270, for example I read 100mm so I add 1.5 crop factor to that arriving at 150mm. I believe that tells me to get about the same shot I need a 150mm ff lens. Im having a hard time buying into this, am I nuts?

 

[astroNikon]

That's about right. The 150mm on FF.
on the Wide side your 18mm, all you need is about 26 (or 24mm or 28mm) to be equivalent on FF.

The nuts part might be right too but you'll have to have a professional judge that

 

[Braineack]

18-55 dx = 24-70 fx

 

[gr8five]

18-55 dx = 24-70 fx

Your using a crop factor of 1.3 or am I missing something?

 

[Braineack]

can you buy a 27-82.5mm lens?

i should have have specified that I was just referring to the common zoom range standard lens.

 

[astroNikon]

but he has a Tamron 18-270 on DX,
which is 27 - 405mm equivalent on FF, which I don't think there's ONE equivalent lens. But a 24-85 and a 70-300 might cover alot of the range for a smallish budget.

But if he only wants to cover the 150mm range then the 70-300 might be the most versatile.

 

[astroNikon]

can you buy a 27-82.5mm lens?

i should have have specified that I was just referring to the common zoom range standard lens.

Use a 24-85, and use some tape so it stops at 27 and 82.5

 

[Braineack]

can you buy a 27-82.5mm lens?

i should have have specified that I was just referring to the common zoom range standard lens.

Use a 24-85, and use some tape so it stops at 27 and 82.5

but he has a Tamron 18-270 on DX,
which is 27 - 405mm equivalent on FF, which I don't think there's ONE equivalent lens. But a 24-85 and a 70-300 might cover alot of the range for a smallish budget.

But if he only wants to cover the 150mm range then the 70-300 might be the most versatile.

there's a 28-300 that gets you close in one lens.

 

[astroNikon]

can you buy a 27-82.5mm lens?

i should have have specified that I was just referring to the common zoom range standard lens.

Use a 24-85, and use some tape so it stops at 27 and 82.5

but he has a Tamron 18-270 on DX,
which is 27 - 405mm equivalent on FF, which I don't think there's ONE equivalent lens. But a 24-85 and a 70-300 might cover alot of the range for a smallish budget.

But if he only wants to cover the 150mm range then the 70-300 might be the most versatile.

there's a 28-300 that gets you close in one lens.

oh yeah, so there is a lens like that the OP could get if he wanted most of the range on FX ==> Nikon 28-300mm VR Review

 

[gr8five]

I looked at the 28/300mm but thought I might get better pictures using smaller lenses. This is why I'm appreciating all the opinions and suggestions. I guessing the DX crop factor isn't part of the lens? If thats true why build a DX lens at all?

 

[gr8five]

can you buy a 27-82.5mm lens?

i should have have specified that I was just referring to the common zoom range standard lens.

Use a 24-85, and use some tape so it stops at 27 and 82.5

but he has a Tamron 18-270 on DX,
which is 27 - 405mm equivalent on FF, which I don't think there's ONE equivalent lens. But a 24-85 and a 70-300 might cover alot of the range for a smallish budget.

But if he only wants to cover the 150mm range then the 70-300 might be the most versatile.

there's a 28-300 that gets you close in one lens.

There's also an 18/300mm lens that I looked at.

 

[Braineack]

I looked at the 28/300mm but thought I might get better pictures using smaller lenses. This is why I'm appreciating all the opinions and suggestions. I guessing the DX crop factor isn't part of the lens? If thats true why build a DX lens at all?

Dx lenses are cheaper to make.

using tapatalk.

 

[480sparky]

DX lenses simply project a large enough image to cover the smaller sensor.

It's not the same focal length you want......... it's the same field of view you want. A 100mm lens is 100m, whether it's on a cell phone or a 20x24 view camera, or anything in between.

 

[Braineack]

even cropped, the OOF would be a bit different because of the CoC. IIRC, the crop should have in this instance a more blurred looking bg if you cropped the FF image down to match the same FoV.

 

[nerwin]

your assessment of bokeh and OOF is not entirely accurate.

basically the same does not equal the same. The FF camera will have about a stops difference look to the OOF area between the two.

Guess I was wrong then, my bad.