is there a chart? Lens conversion

[Happy Hour]

Just wondering if there is a chart that tells you what the lens conversion is from a 35mm to a dlsr? Like my Minolta 50mm is actually a 75mm on my Alpha. Is there anything like this out there? So i don't have to keep asking every time I find a lens I want?

 

[JerryPH]

Why is this even needed? No one purchases lens using cropped sensor numbers.

Do you know the cropped sensor size of your camera or do you know the ratio?

It is usually 1.5 for Nikons and 1.3 or 1.6 for Canons.

Also... your zoom amount doesn't change, just the field of vision (width and height).

 

[Josh66]

Just multiply by 1.6 (or whatever factor your camera needs), no chart needed - unless you're not good at multiplication, but then you could make your own chart.

 

[Happy Hour]

Why is this even needed? No one purchases lens using cropped sensor numbers.

Do you know the cropped sensor size of your camera or do you know the ratio?

It is usually 1.5 for Nikons and 1.3 or 1.6 for Canons.

Also... your zoom amount doesn't change, just the field of vision (width and height).

I am buying minolta lenses for my sony alpha a100 I know that the lens is different on a alpha than it is on a 35mm like my 50mm f/2.8 is like a 75mm f2.8, and my 80-200 is like 125-300. So I found a bunch of lenses and want to know what they convert to on my alpha. But I don't want to have to post a question a bug everyone every time I find a lens. I believe mine is a 1.5 but how does that tell me what I need to know? I honestly have no idea what you mean by cropped sensor numbers. I'm just starting out and am reading and learning more everyday. Thanks for the help

 

[Happy Hour]

Just multiply by 1.6 (or whatever factor your camera needs), no chart needed - unless you're not good at multiplication, but then you could make your own chart.

Ok just so I don't fudge this up if i'm looking at a 80-200mm and my camera is 1.5 I multiply the 80 by 1.5 then the 200 by 1.5 and thats my conversion?which is 120 x 300 am i right?

 

[Josh66]

50mm x 1.5 = 75mm. It's as simple as that.

 

[Josh66]

Ok just so I don't fudge this up if i'm looking at a 80-200mm and my camera is 1.5 I multiply the 80 by 1.5 then the 200 by 1.5 and thats my conversion?which is 120 x 300 am i right?

Yup, that's right. And if you do suck at multiplication (no offense intended) 1.5 is easy. Just add half of the number. 80 x 1.5 is the same as 80+40. It's pretty simple, but some people have trouble with it...

 

[Happy Hour]

Wow i didn't realize it's that simple! Thank you for explaining it to me!! and the f stop doesn't change right?

 

[Josh66]

Wow i didn't realize it's that simple! Thank you for explaining it to me!! and the f stop doesn't change right?

F stop will be the same, the hole in the lens is the same size as it always was. (And the focal length is the same too, really. You're just cropping off the edges of the image.)

 

[Sideburns]

no, the aperture is the same. But one thing you should know...
Forget about the conversions for now. If you want a lens, try it out...if it works, it works.

Say you have a 50mm.
If you want longer, you'd get 100mm, 135mm, 200mm, 300mm....whatever...if you want shorter, you'd get 35mm, 28mm, 14mm....

You don't technically have to convert the lens to the "equivalent" to know if you should get it or not. Just trying to simplify things...

 

[Happy Hour]

Thanks sideburns! It's mainly I keep finding new lenses around the house and we were talking about teleconverters well I found a lens that gives me more than the teleconverter would for $30 on ebay

 

[Sideburns]

Thanks sideburns! It's mainly I keep finding new lenses around the house and we were talking about teleconverters well I found a lens that gives me more than the teleconverter would for $30 on ebay

Well if it's 30 dollars on ebay, it's most likely not that good.
I know they have lots of phoenix and quantaray stuff online for cheap....but I personally wouldn't buy it. I'm not saying don't...but I wouldn't expect the highest of quality.

Want to give the specifics? what's the lens you found? What lens and what teleconverter are you comparing to?

 

[Happy Hour]

it's a used Sigma for minolta all the lenses I have are on there and they are all running around $10-$50 I don't think most people know that sony can use minolta equipment.Cause the majority of Minolta lenses on there are going for nothing. I already purchased one and it is in great condition almost new!