View Full Version : f/1.4 Question
JeremyLangford
10-27-2007, 11:35
Ok. I have a Miinolta SRT-101 with a Rokkor 50mm f/1.4.
I have always loved this lens, but hadn't taken many pictures with it. Last week I went to Damascus, Virginia with my family and tried taking some pictures of all the ausome fall colors, and when I got my pictures back, I realized that my DOF was way to shallow in some of the close ups. I know the DOF should of course be shallow when using an f/1.4, I just didnt see that it was too shallow until I got the pictures back.
Here are some examples.
http://i21.tinypic.com/n3uic8.jpg
http://i20.tinypic.com/357oze1.jpg
Anyways, my question is, would it be fine for me to just use my DOF preview and take the aperture up or does this hurt the sharpness a lot? It seems like I always hear that you shouldn't take your aperture up, but instead just buy a higher aperture lens.
So basically, if I need an f/2.8 for my DOF to be right, should I take my 50mm f/1.4 to f/2.8, or should I buy a 50mm f/2.8 and use it wide open?
Time Freeze
10-27-2007, 11:52
You will get maximum sharpness from your lens at F5.6 to f11. Using the lens wide open is not the best if you want sharpness. Your 1.4 lens will function well at a smaller aperature but you will also have a very fast f1.4 if you need it for low light. Close down your lens and you will increase your depth of field.
In this case, with all the fall colors, I would have tried to shoot more stopped down (to include more detail), and used the lens more wide open for isolating detail against a colorful background, like the bottom shot.
:)
It seems like I always hear that you shouldn't take your aperture up, but instead just buy a higher aperture lens.
You will be fine with your 1.4 lens upto f8 at least. Lens performance usually starts to degrade
above f11 or f16 due to defraction, below and including f8 it likely improves.
Best,
Roland.
JeremyLangford
10-27-2007, 12:36
alright sweet. I am very happy to have an f/1.4 then.
Here are some of the pictures that I ended up liking from the trip.
http://i20.tinypic.com/bj8u2h.jpg
http://i20.tinypic.com/oaq145.jpg
http://i24.tinypic.com/2iq5bc.jpg
http://i20.tinypic.com/2nrgh0i.jpg
http://i22.tinypic.com/ayou2g.jpg
http://i21.tinypic.com/160c3mg.jpg
navilluspm
10-27-2007, 12:49
I like the last one the best! Well done.
Very pretty, Jeremy. You definitely know how to handle that lens !
Anyways, my question is, would it be fine for me to just use my DOF preview and take the aperture up or does this hurt the sharpness a lot? It seems like I always hear that you shouldn't take your aperture up, but instead just buy a higher aperture lens.
I don't know of any lens that is at its sharpest wide open, but a good f/2 lens might indeed be sharper at f/4 than a good f/1.4 lens.
Oh, and many modern focusing screens can only gather light up to a certain aperture. You can test for yourself if there is any difference when using the DoF preview at f/2, for instance.
2c, /Jobo
Jeremy, you have a good lens there. With practice you should soon get the results you want.
Nice shots. The bokeh is very similar to that on my 50/1.7 Rokkor -- it looks really nice in some shots and a little weird in others. Wonder if that's a Rokkor design thing...
f1.4 is one of those things where you shouldn't do it just because you can. Also, the further away you are from your subject, the larger the DOF will be at f1.4. 10ft away and it's about 4ft or so. 3 ft away and it's only inches. You just have to get used to actually working with a lens to get the feel of it. One of the reasons I only use primes is that I understand the behavior of each lens and what I can do with it.
As a rule a lens that has a maximum aperture of f1.4 won't be as sharp at say f2.8 as a lens that starts at f2.0. But with quality lenses you hardly notice the difference. So there is no need to buy a slower lens.
Nikon Bob
10-28-2007, 10:04
It was recommended to me to hold the DOF preview down and slowly stop the lens down to see the effect of the different F stops on the DOF. That was for a Nikon SLR so I don't know about Minolta SLRs but I am guessing it would be OK too. As you stop the lens down the view gets darker making it harder to see the differences. The second set of photos look fine to me.
Bob
wolves3012
10-28-2007, 15:14
I agree with Nikon Bob - use the DOF preview button, it's there for a reason. By stopping down to the taking aperture you'll see what DOF you are going to get. Just because you have f/1.4 at your disposal doesn't mean taking all shots at that aperture. There should be a compelling reason to do so, either artistic or just plain lack of light.
Some of the shots you posted are just too shallow DOF, others exploit the same thing very nicely (only my personal opinion, feel free to disagree). The car headlight, for instance, is maybe a bit extreme and I think the shot of the steps is also too shallow. For me it would have been better to get more steps in focus while keeping the background blurred. On the other hand the second set of shots I would say there isn't actually a bad one there.
It's true to say that, generally, a fast lens like a f/1.4 is never as sharp as an f/2, there are more compromises in the design. In reality, however, the difference is quite small and usually only shows in demanding shots and high magnifications. The main penalties of a fast lens are greater weight, bulk and cost.
There is a review of the Minolta 1.4s here (http://www.rokkorfiles.com/Battle%20of%2050s2.htm) which may help you understand what you can expect from your specific lens at different apertures.
JeremyLangford
10-28-2007, 17:04
It was recommended to me to hold the DOF preview down and slowly stop the lens down to see the effect of the different F stops on the DOF. That was for a Nikon SLR so I don't know about Minolta SLRs but I am guessing it would be OK too. As you stop the lens down the view gets darker making it harder to see the differences. The second set of photos look fine to me.
Bob
This is one reason I love my SRT-101.
The DOF preview actually stays on after you press the button and goes off with another press. This can come in handy with a f/1.4 sometimes.
JeremyLangford
10-28-2007, 17:08
I agree with Nikon Bob - use the DOF preview button, it's there for a reason.
Some of the shots you posted are just too shallow DOF, others exploit the same thing very nicely (only my personal opinion, feel free to disagree). The car headlight, for instance, is maybe a bit extreme and I think the shot of the steps is also too shallow. For me it would have been better to get more steps in focus while keeping the background blurred. On the other hand the second set of shots I would say there isn't actually a bad one there.
Thank you. I agree with you and I was surprised to see how shallow my pictures actually turned out when I saw them on the computer.
JeremyLangford
10-28-2007, 17:09
Nice shots. The bokeh is very similar to that on my 50/1.7 Rokkor -- it looks really nice in some shots and a little weird in others. Wonder if that's a Rokkor design thing...
Ha. I started out with that lens. I love both of them.
JeremyLangford
10-28-2007, 17:24
I see you are a new user.
When we talk about the aperture we say "stop it down" rahter than "take it up" when we go to higher numbers. The numbers are a ratio (It is calculated by dividing the focal length by the diameter), so a higher number mean a smaller opening, thus "down." So bigger numbers=less light.
The shutter speeds the same... bigger numbers=less light.
However stopping a lens down increases the depth of field.
Going to a higher shutter speed stops action better. The numbers are also a ratio 1/500th of a second etc.
There are of course many more nuances to all of this, but despite the incredible complications introduced by new electronic cameras, there are only three setting in photography that count, besides choosing your film, F-stop, shutter-speed, and focus.
Dont mean to be mean, but I am not new to photography. I used to be one of the guys you all probably cant stand. I used to use my dad's Digital Canon 30d SLR with automatic everything.
I used to spend all my time on the Canon Digital Photography Forum
( http://photography-on-the.net/forum/ )
When I was there, I was talking to a guy with the username "Tuna" (hes a member here too) and he introduced me to rangefinders and this forum, and I found out what I was missing out on.
I immediately signed up for a B&W film class at my high school and bought my SRT-101 off ebay.
Anyways, my point is, Ive had this argument before of the Canon Forum.
Thats where I learned that aperture is a ratio, that f/ stands for focal length, and the formula to finding the surface area of the aperture size which tells me how the aperture actually halfs or doubles each stop.
The fact is, talking about aperture using the f stop numbers instead of the size of the hole is easiest and how most professionals talk. And I think it is also fine to say "take it up" instead of "stop it down" as long as everyone knows what I'm talking about.
Jeremy,
Welcome to the wonderful world of the fantastically versatile 50/1.4 lens.
A few samples that I think show the versatility.
EDIT: Fix links
The two links are of subjects just a few feet apart and photos taken a few minutes apart. Same film/body/lens. The first at about f=5.6 and the second at or very near f=1.4. Both close to minimum focus distance. I know the 1.4 photo was very close to minimum distance.
Sample @ 5.6 or 8.0 (http://gallery.leica-users.org/v/venchka/backroads/0046281-R1-050-23A-2.jpg.html)
Sample @ 1.4 (http://gallery.leica-users.org/v/venchka/backroads/0046281-R1-052-24A-1.jpg.html)
rogue_designer
10-29-2007, 14:57
venchka - you linked the same photo twice.
Nice shots Jeremy. As you noticed, and was pointed out, the DOF is dramatically thinner at close focus ranges.
As for being "new to photography" - I've been shooting professionally for more than 15 years, and some of the shooters here consider me "new to photography" :D
So I wouldn't worry about it.
I do agree with Nikonhswebmaster - while I can appreciate using terms "as long as everyone knew what you meant" sometimes that lack of precision can be problematic. Learn the correct terms and use them when appropriate.
Well done, love them rokkors.
JeremyLangford
10-29-2007, 17:18
what film did you use?
All I know is it was Fujifilm 400 speed from Wal-mart. Its the only thing Ive ever tried and Im happy with it.
JeremyLangford
10-29-2007, 17:25
venchka - you linked the same photo twice.
I do agree with Nikonhswebmaster - while I can appreciate using terms "as long as everyone knew what you meant" sometimes that lack of precision can be problematic. Learn the correct terms and use them when appropriate.
I promise I already know the correct terms, its just that when I was on my old digital forum, I was told that everyone should talk about it the opposite way then you are saying to, so that It would be easier to understand people because you just have to think about the f numbers and not the aperture size.
But if everyone here does it the right way, than Im gonna join in.
Some beautiful shots there Jeremy - the last 3 or 4 are excellent.
venchka - you linked the same photo twice.
I caught my mistake in checking the post. It's fixed now.
shadowfox
10-30-2007, 09:36
Jeremy, here's the important thing, from your last set of pictures, I can see that you have a good composition-eyes. That's the most important and hard-to-get ingredient :)
As for 1.4 aperture, it's good for certain effects, just don't go machine-gun with it.
For most pictures, f2.8 and 4 will give you plenty of bokeh to play with without sacrificing too much details.
Gosh, I wish it's that colorful around here...
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