[ln1977]

Deep Breath!!

Just wondering, as I am looking at buying a true 1:1 macro lens and I use a D70 is there any difference with regards to the 1:1 reproduction? I understand that the 1:1 means the image you take will be the equivelent to the size of the object in comparison to the sensor size (ie a 16mm Bug would Appear 16mm Long on a full frame sensor) but does this mean that because I dont have a full frame sensor I will not get true 1:1 from a macro lens, will I still get the 16mm bug so to speak.

I hope i've made myself clear

[Dabhand16]

That's over my head, but I'd guess yes. I agree with your logic, but I suspect someone who knows will soon turn up.

[ln1977]

I like to keep you all thinking on your toes so to speak.

[ln1977]

Any recommendations with regards to a lens Nikon fit approx £200 Limit but like always the cheaper the better

[Dave]

Good 1st question & to be honest I'm not sure of the answer Maybe one of you more epxoerienced members can share their thoughts on that one.

As for choice of lens, then the likes of Sigma will come in cheaper than Nikon, so take a look at the Sigma 50mm Macro which can be had for about £160, followed by the Sigma 105mm Macro at about £240.

Alternatively if you already have a Nikon 50mm f/1.8 lens you could consider extension tubes. I know the likes of Steve have achieved good results with this combo.

[AlexMonro]

Originally Posted by ln1977

Deep Breath!!

Just wondering, as I am looking at buying a true 1:1 macro lens and I use a D70 is there any difference with regards to the 1:1 reproduction? I understand that the 1:1 means the image you take will be the equivelent to the size of the object in comparison to the sensor size (ie a 16mm Bug would Appear 16mm Long on a full frame sensor) but does this mean that because I dont have a full frame sensor I will not get true 1:1 from a macro lens, will I still get the 16mm bug so to speak.

I hope i've made myself clear

True 1:1 macro means that you should be able to focus close enough to get an image of an object on the focus plane (film/sensor) the same size as the actual physical object. The size of the sensor is irrelevant to the macro ratio, but may be significant to the coverage, and the size of the object that will fill the frame.

I don't know the actual size of the D70 sensor, or the specific lens you're talking about, but if the sensor is 24mm wide, you could take a picture of a 24mm long bug that would completely fill the frame (OK, the nearer bits might be slightly out of focus, you don't get much DoF that close). If you use the lens on a 35mm film camera, you could take a picture of a 36mm long bug that would fill the frame, assuming the lens isn't a reduced coverage circle digital only type.

So effectively, you get more magnification, in the loose sense, with a smaller sensor - smaller subjects will fill the frame.

Hope this clarifies things.

[sejanus]

Alex sums it up correctly in every detail.

To amplify the point about sensor size: I've been using a very old Vivitar Series 1 90mm macro, which gives 1:2 magnification, on my Canon DSLR. Because of the smaller sensor size, I get an effective 1.6X increase in magnification over what I'd see when I use the same lens on a full frame 35mm, just as with any lens, but I'm still getting the same 1:2 magnification.

I hope this helps Alex's explanation rather than confusing the issue.

[Dave]

Hi sejanus, welcome to Pixalo & thanks for taking to time to answer the query

Thanks also Alex

[ln1977]

Hello all and thankyou for your help and replies, so to settle this am i correct to suggest that with 1:1 to make it simple if somthing goes in to the lens at 15mm long it will in effect come out of the other end 15mm long and if your sensor is 15mm long that object will fill the length of the sensor.
Would I be correct in thinking that if its a 36mm sensor the the object would fill 15mm of that 36mm frame?

I hope i'm seeing the light at the end of the lens now, once again thanks to all
Lee

[sejanus]

Got it in one!

[ln1977]

AlexMonro and sejanus I have given you post some reputation point for your help thankyou Lee

[Rob Barron]

Originally Posted by ln1977

Deep Breath!!

Just wondering, as I am looking at buying a true 1:1 macro lens and I use a D70 is there any difference with regards to the 1:1 reproduction? I understand that the 1:1 means the image you take will be the equivelent to the size of the object in comparison to the sensor size (ie a 16mm Bug would Appear 16mm Long on a full frame sensor) but does this mean that because I dont have a full frame sensor I will not get true 1:1 from a macro lens, will I still get the 16mm bug so to speak.

I hope i've made myself clear

The reproduction ratio is not related to the focal length itself and the size of the sensor makes not the slightest difference. If you put the Canon 100mm macro lens which has a 1:1 ratio on a 30D it will give you the focal length of 160mm at 1:1 ratio whereas if you put it on the v30 or whatever (film camera) it will have a focal length of 100mm at 1:1 ratio.

The sensor size is irrelevant in this context other than that where a 35mm film camera can reproduce lifesize a 36mm caterpillar (in theory at least) because its film plane is 36mm x 24mm whereas a digital SLR can only reproduce lifesize a caterpillar that has had its bum cut off

In short, YES, you will always be able to get 1:1 ratio.
Cheers,
Rob

[ln1977]

Thanks had pretty much got he anwser already but I like the bit where the caterpilla got his bum cut off makes for a better image in my mind Thankyou regards Lee