Two Questions: Lens and Camera

[RBennett]

Ok, so after looking on-line a lot and seeing a bunch of jargon that I don't really want to interpret right now, (mainly because I'm at work and my brain is mush) I'm hoping some really smart people (and there's a LOT of them on here, so please answer) can help. I'm trying to find what the difference is between a full-frame camera and what most of us carry? I'm just flat out curious as to what is the difference both technically, and optically. What is the benefit of a full frame camera over a typical DSLR?

ETA: Ok, so while looking on-line I THINK that I got an explanation of the full-frame camera. I read that the DSLR sensor creates a smaller image than a 35mm camera, even at the same focus level. So the full-frame camera is the digital camera at the 35mm camera image size, correct? What does this do optically? Does it create a "better" picture?


Secondly, and this will be more directed at Pentax users, does anyone recall if they have seen an ultra-wide angle lens that can be used with our K-mount? I have the fish-eye lens that Groucho is so famous for using, but to me it seems almost (no offense Groucho because I REALLY like the shots) like a novelty lens. If you look at the Tokina 11-16 lens it has that really wide angle but it doesn't seem like it distorts the edges or rounds it out at all. I've heard a talk on a Pentax photo thread that with Sony having their Tokina 11-16, will Pentax get one? Any others out there? TIA!!

 

[annnewjerz]

Secondly, and this will be more directed at Pentax users, does anyone recall if they have seen an ultra-wide angle lens that can be used with our K-mount? I have the fish-eye lens that Groucho is so famous for using, but to me it seems almost (no offense Groucho because I REALLY like the shots) like a novelty lens. If you look at the Tokina 11-16 lens it has that really wide angle but it doesn't seem like it distorts the edges or rounds it out at all. I've heard a talk on a Pentax photo thread that with Sony having their Tokina 11-16, will Pentax get one? Any others out there? TIA!!

Not that I wouldn't love to answer your question, but I'll leave that up to someone who can explain it more clearly. I did, however, want to let you know that if you shoot with the fisheye, there are ways to "de-fish" it if you are looking to use it for photos of people and don't want extreme curvature or distortion. ImageTrends makes a plug-in that you can use with Photoshop, Elements and Aperture I believe, that will straighten out vertical lines that are curved, but keep the horizontal lines bendy---if that makes sense.

Google'ing it would probably just be better so you can see for yourself. It's called Image Trends Fisheye Hemi plug-in.

 

[zackiedawg]

You'll likely get some passionate arguments from full-frame users, and defenses from APS-C users...but basically what it comes down to is: full frame sensor is larger, so it can support more pixels with less density, which likely yields ultimately a resolution and detail advantage to an otherwise identical MP count on the smaller APS-C sensor. Pretty much the same type of difference that separates a P&S with a 14MP 1/2.5 sensor compared to a 14MP APS-C sensor in a DSLR. Sure, they both have 14MP, but the larger sensor provides greater resolution, less noise, more detail due to larger pixel sites. Same for full frame over APS-C.

Also, full frame sensors have no 'crop factor' when dealing with lenses - so a lens of 50mm is a true 50mm on a full frame camera, compared to 75mm on a 1.5x crop APS-C camera.

The flip side of that is that you must remember to be careful not to buy lenses designed specifically for APS-C sensors, as they will vignette seriously on a full frame camera. And without the crop factor, zooms don't have quite the reach APS-C users are used to, so cropping in post is required to bring the subject in as close as what you get with the smaller sensor.

As for wide angle lenses - I'm not sure what's available for Pentax, but lots of what are referred to as 'ultra-wide' lenses will yield the results you are looking for - wide angle without fisheye distortion. Most are 'rectilinear' designs, which will do a very good job of keeping horizontal and vertical lines straight even at the widest settings, as long as you are shooting straight on to the subject. Some which are commonly available in most mounts are: Sigma 10-20mm F4-5, Sigma 10-20mm F3.5, Tamron 10-24mm F3.5-4.5, Tamron 11-18mm, and Tokina 11-16mm F2.8. I would think some, if not all, of these should be available in Pentax mount.

 

[Gdad]

I seem to recall the last Full Frame vs. Crop Sensor thread went horribly wrong.

Ann- OT but can you post some before/after examples of a few de-fished fish-eye shots some time? I'm curious how much of the image edge is lost in the conversion process.

 

[VVFF]

Ok, so after looking on-line a lot and seeing a bunch of jargon that I don't really want to interpret right now, (mainly because I'm at work and my brain is mush) I'm hoping some really smart people (and there's a LOT of them on here, so please answer) can help. I'm trying to find what the difference is between a full-frame camera and what most of us carry? I'm just flat out curious as to what is the difference both technically, and optically. What is the benefit of a full frame camera over a typical DSLR?

ETA: Ok, so while looking on-line I THINK that I got an explanation of the full-frame camera. I read that the DSLR sensor creates a smaller image than a 35mm camera, even at the same focus level. So the full-frame camera is the digital camera at the 35mm camera image size, correct? What does this do optically? Does it create a "better" picture?


Secondly, and this will be more directed at Pentax users, does anyone recall if they have seen an ultra-wide angle lens that can be used with our K-mount? I have the fish-eye lens that Groucho is so famous for using, but to me it seems almost (no offense Groucho because I REALLY like the shots) like a novelty lens. If you look at the Tokina 11-16 lens it has that really wide angle but it doesn't seem like it distorts the edges or rounds it out at all. I've heard a talk on a Pentax photo thread that with Sony having their Tokina 11-16, will Pentax get one? Any others out there? TIA!!

Full frame is just another size of sensor. Most DSLR's out now use "crop sensors" which are smaller than full frame sensors just the same way that a 4:3 typical P&S sensor are smaller than "crop sensors" even though, those too, are technically "crop sensors".

What this does is affect the equivalent focal length of the lens, high ISO ability and depth of focus. As the sensor gets larger the depth of focus gets smaller due to the actual focal length being used(not the 35mm equivalent). For example, most P&S cameras are a 6x "crop sensor" approximately and start at 6mm focal length lenses. This is equivalent to a 36mm lens in full frame terms but depth of focus is determined by the actual focal length. In this case, that's 6mm.

From a 1.5 or 1.6x crop sensor DSLR I've seen that the DOF is approximately 1-1.5 stops different. That means that a image taken at F2.8 on a full frame sensor will have equal depth of focus to a F2.0 one on a crop sensor(1.5 or 1.6) approximately.

Secondly, the typically expand the usable ISO range. Generally speaking(ignoring other advancements in sensor design) larger "pixels" on the sensor can be amplified to greater ISOs with less noise. I find that the 5D Mark II has about a 1.5 or maybe 2 stop improvement on the 50D in terms of noise performance. This means that ISO 800 on the 50D is equivalent noise wise to maybe around ISO 2000 on the 5D Mark II. These will vary from camera to camera.

Lastly, full frame affects field of view. When using crop sensors you multiple the 35mm focal length of the lens by the crop size. So a 17mm lens becomes a 27mm or so lens. So using a 17mm lens on full frame gives you a extreme wide angle view. Using that same lens on a crop sensor gives you a mild wide angle view. This can sometimes be referred to as helping with reach as the converse is also true. Using telephoto lenses on a crop sensor multiplies the focal length by the crop factor and you have the equivalent to a "longer" lens. One can argue that the same effect can be achieved by cropping the full frame image down to the crop cameras size but this will be a significant loss in resolution.

 

[Bstanley]

As a new owner of a crop sensor DSLR I am looking forward to some day buying a full frame sensor DSLR. I'll take a stab at describing the two.

The primary difference is simply one of area. A crop frame sensor has approx 50-60% of the area of a full frame sensor. If both sensors had the same number of light sensitive spots (photosites) that means that the photosites on the full frame sensor have twice the area of those on a crop frame camera.

Why is that interesting? A larger area means that a photosite can be more sensitive to incoming light (like a bigger window allows more light in). Also you can think of a photosite like a bucket that holds light. If the bucket is larger the range of values between empty and full can also be larger - so the full frame sensor can provide a higher dynamic range (wider variety of light values).

Or you can make the photosites the same size on the full frame sensor as on the crop frame sensor and get a sensor that has twice the resolution - number of photosites - but with the same sensitivity and dynamic range.

The disadvantage of a larger sensor is cost. The sensor itself is more expensive and the lens you use is more expensive because it has to be of a larger diameter to deliver the image to the larger sensor.

 

[Master Mason]

Time to break out Oblio's picture again

The circle is what the lens "sees" the Yellow box is what a full frame would capture and the pink box is what a crop sensor would capture.

 

[RBennett]

You'll likely get some passionate arguments from full-frame users, and defenses from APS-C users...but basically what it comes down to is: full frame sensor is larger, so it can support more pixels with less density, which likely yields ultimately a resolution and detail advantage to an otherwise identical MP count on the smaller APS-C sensor. Pretty much the same type of difference that separates a P&S with a 14MP 1/2.5 sensor compared to a 14MP APS-C sensor in a DSLR. Sure, they both have 14MP, but the larger sensor provides greater resolution, less noise, more detail due to larger pixel sites. Same for full frame over APS-C.

So does that explain the detail/sharpness/clarity that I see in a certain someone's photos? **cough-Jeff-cough** Not to give him a big head, but his recent photos is the best example that I can think of. For instance, I took this shot below and I know that if I had left the shutter open longer or widened the aperture it probably would have come out "brighter" but it seems that might photos lack that "wow". It doesn't have that sharpness/clarity that I am looking for.

Here's another one to illustrate my point.

 

[jupster75]

This picture ^^^^^^^^^^^^^ helps a bunch. EDIT! Someone posted before me.

 

[annnewjerz]

Ann- OT but can you post some before/after examples of a few de-fished fish-eye shots some time? I'm curious how much of the image edge is lost in the conversion process.

Sure can! Just got the fish this week in the mail and won't have a chance to take many sample pics until this weekend---but boring as they are, I'll still try to post some examples for you, probably in a separate thread so as to not completely hijack Robby's.

I've seen some really good examples over on the Cafe, which is where I first heard about it. I'll see if I can dig up a few and link them to you in a PM also.

 

[RBennett]

Sure can! Just got the fish this week in the mail and won't have a chance to take many sample pics until this weekend---but boring as they are, I'll still try to post some examples for you, probably in a separate thread so as to not completely hijack Robby's.

I've seen some really good examples over on the Cafe, which is where I first heard about it. I'll see if I can dig up a few and link them to you in a PM also.

Hey! Don't mind me! I'm just the guy whose thread you're hijacking!! Just kidding! You're welcome to post them in a new thread or here, whichever you like, but I am anxious to see them too because if it helps to straighten the edges it might save me $700 on a new lens!!



- Robby

 

[Evad]

I seem to remember someone saying the the full frame camera creates much more "yummier" pictures.....

 

[Gdad]

So does that explain the detail/sharpness/clarity that I see in a certain someone's photos? **cough-Jeff-cough** Not to give him a big head, but his recent photos is the best example that I can think of. For instance, I took this shot below and I know that if I had left the shutter open longer or widened the aperture it probably would have come out "brighter" but it seems that might photos lack that "wow". It doesn't have that sharpness/clarity that I am looking for.

I really don't see a problem with the sharpness on the examples you posted- I looked at the larger size files on your Smugmug site and they look good. Your 2008 Hallowishes look really really good in fact. Fireworks are always kind of hit and miss- for me at least- depending on a lot of factors. I definitely don't think the sharpness and clarity has anything to do with using a full frame camera.

I am curious about the dynamic range demonstrated in these though- did you shoot in raw or jpg? And if you shot in raw did you do any processing to try to recover the blown out highlights and/or lighten up the dark areas of the frame? It's hard to really judge how much light is hitting the crowd and surrounding area from the fireworks but I seem to remember a recent similar shot that included the partners statue that Tom Bricker posted a while ago that seemed the dark areas were much more illuminated.

I seem to remember someone saying the the full frame camera creates much more "yummier" pictures.....

Someone eh? Probably that 'KramBerries' guy- he's always starting trouble.

 

[boBQuincy]

I seem to remember someone saying the the full frame camera creates much more "yummier" pictures.....

If we look at DXOMark scores for dynamic range and color depth we see that the full frame (and medium format) cameras mostly score at the top. These two parameters could translate to "yumminess". HDR on a smaller format can make up for some of the range and depth but it is still no replacement for getting it all in one frame to begin with.

Except for the size, weight, and price of FF there is little reason to get a crop sensor camera. If they weren't so large and heavy I would carry a FF and I am still thinking of getting one just for the "yummiosity".

 

[Jeff Fillmore]

Someone eh? Probably that 'KramBerries' guy- he's always starting trouble.

Yeah- I'm sure it was him.

 

[mom2rtk]

I seem to remember someone saying the the full frame camera creates much more "yummier" pictures.....

So would that "yummier" term be one of those technical terms only an experienced photographer would know????

 

[ukcatfan]

Yeah- I'm sure it was him.

OK, do I need to create an alter ego account as well I don't want to be left out!

 

[RBennett]

I am curious about the dynamic range demonstrated in these though- did you shoot in raw or jpg? And if you shot in raw did you do any processing to try to recover the blown out highlights and/or lighten up the dark areas of the frame? It's hard to really judge how much light is hitting the crowd and surrounding area from the fireworks but I seem to remember a recent similar shot that included the partners statue that Tom Bricker posted a while ago that seemed the dark areas were much more illuminated.

Well, it's funny you mention that!! Not to copy his shot, but that was EXACTLY the shot I was trying to duplicate this past trip because Tom's is on an early page of the Ultra-Wide thread. Here is MY attempt:

The biggest difference that my wife just pointed out to me about 5 minutes before I saw your post (which is why I thought it was funny you mentioned that) is it looks like they still had lights on in Tom's shot but they turned EVERYTHING off right before our fireworks. But to answer your question, I shoot 100% in RAW; every time. Perhaps I need a lesson/class in post-processing, which I would love to do. If anyone wants to see what they can do with one of my RAW files I will be happy to email it to them.

 

[Gdad]

Cool- I'd like a shot at this one...

jeff@capturelifeinaction.com

 

[Pooh_Girl]

Cool- I'd like a shot at this one...