Lens model number conventions

[ramborums]

Hi,

The various models of lenses have letters like DG, ES, EX, etc. Do these have any indicative meanings? Or are they just randomly chosen letters? Could someone give a link where more details on this can be viewed?

thanks

[carregwen]

Hi,
Do these have any indicative meanings? Or are they just randomly chosen letters? Could someone give a link where more details on this can be viewed?

A very good question.

They have very specific meanings, and you should note them carefully when purchasing a lens. Here are the Sigma ones... http://www.sigma-imaging-uk.com/supp...iviations2.htm

If buying Sigma, always try to get DG as they will fit full-frame as well, if you get a full-frame camera in future. Like-wise for canons - get 'EF'.

This lists most makes ....http://www.parkcameras.com/article/2...eviations.html

This one also lists Tokina.,.. http://www.marthijnvandenheuvel.com/...abbreviations/

[ramborums]

thanks very much carregwen. that was very valuable.

[rick55]

... Like-wise for canons - get 'EF'.

Not to hijack the thread, but this is a question I pondered before, and decided to try to mostly go with subframe (EF-S) lenses. I don't foresee going to FF sensor, and I figure I'd rather have a lens optimized for my sensor. I realize that for most of Canon's (and I'm sore most manufacturers' lines), FF = best quality. But engineering is all about trade-offs, and I'd rather get a lens where there's no chance that the designers gave up some quality at the center to get some parameter better at the corners, when I'm not using the corners.

Anyone want to disabuse me, let me know I'm buying Canon's marketing material?

Cheers,
Rick

[carregwen]

Anyone want to disabuse me, let me know I'm buying Canon's marketing material?

I think you are supposed to do that!!!

...this is a question I pondered before, and decided to try to mostly go with subframe (EF-S) lenses. I don't foresee going to FF sensor, and I figure I'd rather have a lens optimized for my sensor. I realize that for most of Canon's (and I'm sore most manufacturers' lines), FF = best quality. But engineering is all about trade-offs, and I'd rather get a lens where there's no chance that the designers gave up some quality at the center to get some parameter better at the corners, when I'm not using the corners.

It's a good point. I started with 30D, then 50D, and then I got a used 5D. The 5D produces great image quality, but it's full-frame so I had to start jiggling my lenses around. It's not ideal, and I suppose one should really stick to one format. But the problem still remains that you generally get better IQ with a full-frame because its larger sensor has a better pixel density rate, although the lens can make a huge difference. ATEOTD, I just want a quality lens/camera combination that does its stuff. I can do the rest.

Does any one think the full-frame v APS-C is rather irrelevant now?

[rick55]

Does any one think the full-frame v APS-C is rather irrelevant now?

I certainly see advantages (and a few disadvantages) to full frame. I mean, fundamental physics says that there's more room for a lens sweet spot before diffraction starts to bite. And while the aperture for getting the DOF you want may just be relative, when it shifts off the end of the available apertures, it can cause a problem.

My point is that if I'm going to stick with 1.6 for the foreseeable future, I can get best value in lenses by buying the top of the line EF-S, since the lens designers are building the lens for my sensor, and not making compromises that might be valuable for the person with a FF sensor, but are pure negative for me.

Cheers,
Rick

[Colin Southern]

I would put top of the line EF-S lenses on an equal footing with their EF counterparts. I think that often people zero in on small details and then proceed to make mountains out of molehills; Lab rats aside, I think a good test would be to ask "if someone put a properly processed shot taken with a FF camera and FF lens alongside a properly processed shot taken with a crop-factor camera & an EF-S lens, would people be able to tell which was which? The short answer is "no".

As you mentioned, each technology has advantages and disadvantages with one often offsetting the other eg for a given depth of field, the FF will need to be stopped down 1 more aperture or have the shutterspeed halved - and doing this WILL take the FF camera one step closer to diffraction limits (and probably negating much of it's "advantage" in the process) or the slower shutterspeed may invite more motion or subject bluring (eg tree movement in wind if shooting landscape). Additionally, diffraction & noise are also (in my opinion) grossly over-rated. Assuming a correctly exposed and composed image (where not too much is being cropped) you'd have to make a HUGE print before you can see the effects of diffraction. In real-world and regular sized prints it just isn't significant (or if it is then I'd better give the many satisfied owners of my 44" wide prints shot @ F32 their money back).

At the end of the day, correct shooting an processing techniques will make a one hundred fold bigger difference than FF -v- crop.