Do You Really Need Fast Glass

smoke665

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It's that time of the year again when I re-evaluate my equipment and succumb to gas pains. I've been drooling over this one since release, Pentax HD PENTAX-D FA* 85mm f/1.4 ED SDM AW Lens but do I "really" need it???? I already have a pretty full stable at my disposal, some of which encompass the 85mm focal range and of late I'm beginning to even question the need for the fast glass I already have.

Most of my photography uses supplemental light and the high ISO capability of my cameras makes it hard to justify the large cash outlay. Rarely do I shoot wide open, especially on portrait work as I'm not a fan of only partially having the face in focus, Bokeh/OOF blur aren't necessarily an issue if you adjust your distances to achieve the DOF, and raising the ISO eliminates low light problems. Then you get into into the weight factor, like most fast glass this thing weighs in just under 3 lbs, add another 2+ lbs for the body, that's a lot. By comparison the 70-200 f2.8 is just under 4lbs, and from experience I find myself not using it as much, because the the weight is a PITA.

So how many others are questioning the benefits?
 
It depends

Do YOU have a use case for FAST glass?

For APS-C:
- For field sports, I gave up on the 70-200/2.8 and got the 70-200/4 at HALF the weight. The f/4 lens is much easier for this old man to lug around for a few hours. But I was at a field where my f/4 lens was too slow, and I wished I had the f/2.8 zoom.
- In the gym, I use the 35/1.8. Cuz it is FAST, but small and light, so easily handled.

For m43:
I switched to m43 to reduce the kit weight of my APS-C kit that I had to lug around.

- For field sports, I use the 40-150/2.8. It is about the same weight at the Nikon 70-200/4.
- In the gym however, I now use the 12-100/4. I took a 1 stop hit in lens speed vs a f/2.8 zoom, but the wider range zoom flexibility was fantastic. I can shoot both near and far court without changing lenses.
The combination of zooming tighter onto the subject, and with the Olympus/OMDS OM1 cranking the ISO up to 12800, was better than cropping into a shot from the older EM1-mk2 at 6400 + the shorter range 12-40/2.8.

For daytime shooting with both APS-C and m43, I can and often do use slower lenses.
In fact, when I retire from shooting high school sports, I may sell the fast and HEAVY zooms, since I may not be using them.

My m43 travel kit is a Panasonic/Lumix 12-60/3.5-5.6 + Olympus 17/1.8.
I found the 12-60 to be entirely adequate for my travel/vacation use. I think I used the 17/1.8 less than 6 times.

For ME, a FAST lens is for exposure, NOT DoF.
Most of the time I want MORE DoF. I RARELY look for less DoF. But I don't shoot portraits.
 
To add to the famous Wallis Simpson quote, "You can never be too rich or too thin" or have too-fast glass.

Despite the weight, bulk and expense, those fast 85s do allow you to do things with portraits and available/reflector light only for "looks" that goosed ISO and lighting just can't deliver IMHO. The weight isn't that much for just schlepping around a portrait shoot.
 
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depends

Do YOU have a use case for FAST glass
That was kind of the point of the post, I'm not sure I do. As I said I rarely shoot ambient any more, and in low light both the APS-C and full frame can easily handle 4 stops plus in ISO.

Despite the weight, bulk and expense, those fast 85s do allow you to do things with portraits and available/reflector light only for "looks" that goosed ISO and lighting just can't deliver IMHO.

Such as???? That's the question I keep asking myself, and haven't come up with a viable answer. In studio my go to range is f/8.
 
That was kind of the point of the post, I'm not sure I do. As I said I rarely shoot ambient any more, and in low light both the APS-C and full frame can easily handle 4 stops plus in ISO.



Such as???? That's the question I keep asking myself, and haven't come up with a viable answer. In studio my go to range is f/8.

Then, I would say no.
 
I love fast glass, but I don't really need it, often. Currently shopping for a 70-200 f/4 because the cost and weight penalty of 2.8 just isn't worth it to me. Your subject separation gets better and better as your focal length increases, so your bokeh at f/4 at 200mm is pretty nice, actually.
 
To add to the famous Wallis Simpson quote, "You can never be too rich or too thin" or have too-fast glass.

Despite the weight, bulk and expense, those fast 85s do allow you to do things with portraits and available/reflector light only for "looks" that goosed ISO and lighting just can't deliver IMHO. The weight isn't that much for just schlepping around a portrait shoot.

In the case of lenses, what is the cost of that FAST glass.

Not only the $$$$ cost, but bulk/size/weight.
FAST glass is useless if it is so big/heavy that you don't use it.

Example, I cannot free-hand a 70-200/2.8 for two sequential field games. So, I end up shooting off a monopod, which significantly reduces my ability to shoot, as I cannot track a moving subject over a wide arc on a monopod. Hence my use of the 70-200/4, which I can shoot free-hand. I will shoot free-hand for as long as I can, before I "have to" shoot with a monopod.

Smaller lenses, like 50/1.4 is easily carriable. So more likely to use.
24-70/2.8 is borderline. It is heavier than I would like to carry, but not as heavy as the 70-200/2.8.

But, having said all that, "in LOW light, FAST glass wins." That was true 40+ years ago, and is still true today.
I was at a high school field where the lighting was DIMMER than my school, and I was at a borderline unusable exposure.
ISO 25600, f/4 (wide open), 1/125 sec. A f/2.8 lens would let me lower the ISO or raise the shutter speed.
 
Buying used or new?......If you find a deal on a used one then why not. Nice looking lens...I don't think you can ever have enough lenses can you?
 
Not all the time or even much of it, but there are times when fast glass is needed to get the results I want.
Specifically in 85mm focal length I don't have anything faster than f/2.8, but my 50/1.4 on APSC is not too dissimilar in FOV & can be used on FF too. I'm not so sure about my 150mm f/1.2 (for 5x4) I've yet to try it in low light, but it's weight is significant, and the camera /tripod to go with it are somewhat weighty too. Within 100yds of the car will probably be workable :).

FWIW raising the ISO doesn't work well with film, and has noticeable issues when shooting in what I consider low light - i.e. not just indoors or dusk.
Fast lenses do not normally live in my camera bags, but prove very useful when the subject demands it. I now have multiple options but none that required large financial outlay.
 
because the cost and weight penalty of 2.8 just isn't worth it to

Yeah I had a bad case of GAS, just had to have the HD D FA 70-200mm f/2.8, but not only is it a beast to hold, it's a lot of weight to put on the mounting flange of the camera. I ended up buying an articulated support bracket that provides another mechanical attachment.. More weight😒

As to bokeh, I have an old Pentax legacy 135mm f/1.8 that beats out everything in the bag on OOF. From creamy backgrounds to big bokeh balls, it does it all.

In the case of lenses, what is the cost of that FAST glass.

It's not so much the cost in $$$$ if I want/need it, I buy it, but I'm finding as the years go by I'm more critical of need. In your case shooting sports fast glass would be a critical need. I remember well my newspaper days on the sidelines.
 
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Buying used or new

Unless it's an old legacy model I typically buy new. I've been a brand fan since the late 60's. Pentax's commitment to "backward/forward compatibility" has been the reason. When you amortize the cost over many years, cost is not an issue.

@petrochemist my kit currently includes 5 zooms, on of which I'd consider fast, and all encompass the the 85mm focal range. I have 5 primes all fast that bounce around the 85mm.

I'm thinking the money would be better spent on replacing the K3Ii with the K3MIII. Or waiting for an upgrade release on the K1MII.
 
For me the weight of the lens is a primary consideration since I am out and about carrying my gear in the woods or around the city. But if you’re mostly in studio that doesn’t really matter to you.

Build quality, cost, weight, resale value, IQ, bokeh quality, versatility, low light needs, sharpness… what are your primary concerns?
 
Yes! YOLO! In all seriousness, it depends on what you plan on using it for. How much sharper is the lens compared to the ones you have now? Weight a factor? Do you have a local place to rent one from and see if you really want to invest?
 
Renting first is a fantastic idea.
 

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