- This topic is empty.
First Lens selection
-
Okay..thanks Joseph… :D
I was wondering why most of these lenses don’t state the minimum aperture as well as the max? I imagine this is just as important.
Or am I missing something?
Btw…just found this link which is pretty good…wish I had time to read through it now though… :D
http://www.photoxels.com/tutorial_aperture.html
Diffraction may become a problem before you hit the limit of your minimum aperture,
and most of these lenses wont stop down enough to get over this problem-
whatever lens you choose,
I don’t think selecting a small aperture will be a problem-j
Okay..thanks for that Joseph. The whole lens end of things seems to be where most of the confusing technical issues arise..as I suppose it should since it is the most important part of the camera from an image point of view.
Lots of stuff to learn ..I feel like I’m at school again.. :wink: and that wasn’t today or yesterday I can tell ya…!
Robbie
8)Indeed – it’s f3.5 at 18mm, and f4.5 at 70mm. As jb said, you’ll always be able to get at least up to the f22 range without any worries at all – and probably higher.
So that would be why a lens like the 50mm f1.8 would be invaluable for getting good DOF right? It’s one thing I really love in shots…like most people I guess..and something which is pretty difficult to do with my current Fuji S5600. It’s max Aperture is 3.5 I think…and that isn’t even the same as 3.5 on a DSLR..more like 8, or so I read in Understanding Exposure. That is one of the things I’m really looking forward to experimenting with :D
Cheers
Robbie
8)Shallow depth of field is easier to achieve
with a large aperture,
and a large image-There is a lot of confusion about focal lengths,
because everything gets equated back to some 35mm format ideal-
because there was a time when pretty much everyone was familiar with the effects of optics on the 35mm format.Now that people are coming into photography afresh,
so to speak,
and the variety of image sensor sizes are getting larger, (while the sensors get smaller)
I can see how it would be difficult to have to keep translating everything in and out of the 24x36mm standard.Interesting now that you’re translating aperture/DOF parameters from compact to DSLR-
its a minefield- is that a crop DSLR?Crop DSLRs will have more DOF for a given aperture than a FF DSLR-
As with everything,
there is no substitute for experience,
so get out there and start using your new camera-It seems like you have a good grasp of the principles,
and the questions you’re asking are the right ones-j
Just a quick point – YES aperture does relate to DOF, but so does focal length. If you use a F1.8 lens at F4, it will result in a much sharper image than using it at F1.8. Using a lens at it’s max aperture normally results in a poorer pic than using it in the middle somewhere.
For that reason, I’d personally rather use (for example) a 100mm F2.8 lens F4 than a 50mm F2.8 lens at F2.8. Both will achieve similar DOF. Clearly it will depend on the circumstances if you can get away with that, but I’d suggest not using a lens at it’s widest aperture unless you have to. Buy an F2.8 lens to use it at F4, but an F4 lens to use it at F5.6 etc.
Hope this makes sense.
Tim
I feel like I’m back in Math class again…heheh!!
But yes..it does make sense Tim… :D
I have the 18-70mm kit and the 50mm 1.8
I find I use the 18-70 most of the time. Also I didn’t think I would use the wide end so much, but turns out I take most pics at that end. If you can get a good price on the kit I would consider getting that one for starters (not sure what the 18-135mm kit lens is like, but extra range must be handy. 70 can be a bit limiting)
There was a Tamron 24-75 f2.8 Nikon fit for sale in the for sale section. If you didn’t mind the lack of wide angle, it’s meant to be a great lens.
Personally I would go for something like the 18-70 or -135 and after a while see where your interest lie.
Thanks DMG ..is a bit bewildering okay..not least so because there is such a huge variance in price between different lenses that seem to have similar numbers after the name.. :wink: I’ve seen that 18-135mm one and on paper you’d think ti would be ideal starting off..yet it seems cheap compared to some of the others..
Ah well..sure I have plenty of time to ponder all these names and numbers before I have the money…maybe by then I’ll have my head around the whole thing..(or better…have won the lotto and be able to forget price altogether :wink: ). Fat chance!!!
Robbie
You’ll be glad you asked all this now…
I bought the Canon 17-40 F4L thinking that there was no reason that I should pay triple the amount for a 16-35 F2.8L.
I was wrong.
17-40 is great, but the 16-35 is soooo much better, despite them being numerical brothers and sisters! lol
Tim
Expresbro wrote:
Thanks DMG ..is a bit bewildering okay..not least so because there is such a huge variance in price between different lenses that seem to have similar numbers after the name.. :wink: I’ve seen that 18-135mm one and on paper you’d think ti would be ideal starting off..yet it seems cheap compared to some of the others..
The 18-135 is a bit of a lower quality lens… It has some extra range, but it’s definitely not as high quality as the 18-70.
Do you mean the Canon 28-135 with IS? I use it as a general purpose lens, and rate it fairly highly.
http://www.the-digital-picture.com/Reviews/Canon-EF-28-135mm-f-3.5-5.6-IS-USM-Lens-Review.aspx
Well one of the things that got me interested in pursuing a knowledge of photography was to learn how to take candid street shots and documentary shots..so I think I am going to need a certain amount of telephoto power for that. But I’ve found that the longer the focal length..the poorer the image in general, which is probably to be expected. It’s probably better to use a tripod..but for candid and street stuff..I don’t think that’s really viable..so maybe a 70mm lens would be better anyway. What is 70mm in zoom terms anyway? Is it 3x or 4x or less? I haven’t been able to clarify this with the online reading I’ve done so far.
earthairfire wrote:
YES aperture does relate to DOF, but so does focal length.Tim
Seems obvious,
but is it correct?http://www.luminous-landscape.com/tutorials/dof2.shtml
You must be logged in to reply to this topic.
