macro lens

[tarzieboy]

have been researching macro lenses for my d40, can anyone enlighten me, as to what the difference would be, between the tamron 90mm macro, & the 70mm macro,
the shop informed me, that the 70mm was specially brought out for digital, i cannot go along with that both are d.i, am i correct, or not, & can one explain the difference between the two lenses, is it as i think i.e the zoom range of the lens, thankyou

[ash]

Re: macro lens

Personally I would go with the sigma range, they are as good if not better than the brand names, the focal length is important if you are wishing to photograph insects and such that are spooked by your presence, a longer focal length means you do not have to get as close, but will give the same 1:1 reproduction.

[tarzieboy]

Re: macro lens

thankyou for that info, ash, i guess i would not have to get as near the subject , with a 90mm, as i would a 70,,,,,will look at the sigma,s,,,john

[Patrick]

Re: macro lens

thankyou for that info, ash, i guess i would not have to get as near the subject , with a 90mm, as i would a 70,,,,,will look at the sigma,s,,,john

I own the Sigma 105mm macro an excellent lens. The disadvantage of the longer focal lengths is that depth of field gets less, an important thing to consider with macro work, so you do need to stop down well. Sigma offer a 150mm and I believe a 180mm.

Patrick

[tarzieboy]

Re: macro lens

thanks for the info patrick, i look at a photo of a flower, the stamen is sharp & the petals out of focus, i would want a little more depth of field than that , would that be possible with the 105mm

[Patrick]

Re: macro lens

thanks for the info patrick, i look at a photo of a flower, the stamen is sharp & the petals out of focus, i would want a little more depth of field than that , would that be possible with the 105mm

[tarzieboy]

Re: macro lens

thankyou patrick, great stuff, i apreciate your skiill & your help am really looking forward to getting the lens & experimenting,,, will let you know how i get on,,,john

[jds9000]

Re: macro lens

Spooky ......
... been 'playing' with my old 28-70mm canon (f3.5-4.5) on my 400D in the conservatory with a sprig from a Laburnum bush .... and stuff !!

f22 4 seconds .... with a 20mm Kenko extension tube .... tried several times and just couldn't get the depth of field right. For a group of shells on the flat .... perfect ... clear as a bell, but anything with a bit of depth, lots of trouble. Tried it with the tubes, without, 18-55mm, my 50mm, even my 70-200 L. Varied results, but still not quite there ... frustrating this camera lark init ??

Jay

[tarzieboy]

Re: macro lens

interesting jay, i hope to be having a go myself soon, patrick was saying ,
"that as the focal lengths get longer the depth of field gets less, i would wish to get say, all of the front to back of say a tulip, in focus, so would the 105 mm sigma do the job i envisage,,,john

[Stephen]

Re: macro lens

Spooky ......
... been 'playing' with my old 28-70mm canon (f3.5-4.5) on my 400D in the conservatory with a sprig from a Laburnum bush .... and stuff !!

f22 4 seconds .... with a 20mm Kenko extension tube .... tried several times and just couldn't get the depth of field right. For a group of shells on the flat .... perfect ... clear as a bell, but anything with a bit of depth, lots of trouble. Tried it with the tubes, without, 18-55mm, my 50mm, even my 70-200 L. Varied results, but still not quite there ... frustrating this camera lark init ??

Jay

f22 of course is not the best aperture for sharpness. However for DOF it will give you the greatest.

I remember when using film in the studio and we needed more depth of field. We would be in total darkness using flash. The exposure would be calculated using 2 flashes and this would effectively give you an extra stop and therefore the extra DOF needed. Never tried it with digital

[tarzieboy]

Re: macro lens

so aperture is linked with sharpness,,, jay were you using any other light source than daylight, or any reflectors,,,,,,,john

[jds9000]

Re: macro lens

Nothing, just had it resting on a sheet of white paper

jay

[Stephen]

Re: macro lens

so aperture is linked with sharpness

I didn't actually say that John, however the fact is that lenses have a so called 'sweet spot' where they are sharpest. Its often about f8-11 (less on digicams of course) If you go higher than that it's possible that some sharpness is lost. I'm unsure of the physics of it, Ians yer man for that

[tarzieboy]

Re: macro lens

many thanks stephen,,,,,john

[tonycoyle]

Re: macro lens

The little red spider (mite?) in the lower right would be an interesting subject too!

I'm jealous you have an L - My macro is limited to a very cheap quantary 70-300. (I'd rather have the range to get my kids on the field or swimming - with some distortion - than just have a ten pixel blob in the middle of the frame). Anyway - not the sharpest lens in the world, but I'll maybe post some recent shots for critique.