DSLR vs. P&S with IS

[ukcatfan]

I am now getting close to buying a DSLR and have a question on exposure vs. a P&S with IS. All you DSLR experts, please let me know if my thinking is correct.

The IS on a P&S is supposed to give you about a two stop advantage. Most DSLRs have a usable ISO 1600 that can be even better than a P&S ISO 400. All other things equal, wouldn't that be the same exposure advantage as the IS? I should be able to get comparable or even better low light performance with the DSLR.

I also know that all other things are not equal, with DSLRs having better performance. I know that the aperture on a P&S is not really comparable to true 35mm apertures. I believe that it is sort of like saying that the F/2-3 on a P&S is around a F/7-8 on a DSLR. I would have better light capturing capabilities with the DSLR from this difference.

All of this comes down to me convincing my DW that I am actually going to get better performance with a DSLR. She is a casual user of my S1 IS and likes how she can almost always get a good shot even in lower light. I will still have it around for her and the kids to use, but she will also sometimes use the new DSLR.

I am considering the Pentax *ist DL because, after the rebate, it is around $430. It seems like a pretty good deal for the $. I would go with the kit at first and then invest in a broader ranged walkaround lens within a year. That would probably be it for extra lenses. I would not be investing too much into the Pentax system that way and could switch to Canon , Nikon, etc. in the future without feeling too much of a loss. I am going to wait to see what is released by all of the manufacturers in the coming weeks before making a decision though.

Thank you,

Kevin

 

[Kelly Grannell]

no, having 2 stop advantage IS vs 2 stop advantage ISO are two completely different things. Please refer to the Learn Photography - The Kelly Way for more info.

Cheers.

 

[ukcatfan]

I do not think I stated enough to make myself clear. I understand the differences between the two. I am trying to figure out what results I would have with a DSLR compared to what I know I can do with my P&S. I can go as long as a 1/4 sec. shutter speed handheld with IS on my S1 if it is a stationary subject. With a DSLR, I am usuming that without the IS I can only go around 1/15 - 1/20 sec. without shake. That means that I am taking in less light and would under expose the image. Because the DSLR has a usable ISO 1600, can I compensate for the quicker shutter by increasing the sensitivity and still get similar results? I am thinking that I can actually get better results because the glass is better and I can have a wider aperture.

 

[handicap18]

Don't know if this helps or not, but at 1600 ISO for example, I can take a shot at 1/100th at f/5.6. At 400 ISO on the same subject in the same light, it is 1/30th at 5.6. I just took a quick meter reading using a 70-300mm f/4-5.6 lens at 300mm. So widest aperture was 5.6. Keep in mind that this is just 1 example. I'm using a D50 so the image quality at ISO 1600 is excellent.

 

[Anewman]

I will try.

IS helps photographers hand hold the camera for longer period of time(shutter speed) without movement due to camera shake becoming apparent in the images.

HIGHER ISO allows the sensor to capture the image in a quiker period of time(shutter speed) which also helps avoiding camera shake from being apparent in images, but also helps prevent SUBJECT MOVEMENT from being apparent in images.

Even though ISO 1600 on DSLRs can be usable, I have not met a single photographer that would not prefer the clarity and color of ISO 100. We adjust to higher ISO out of need(lack of light), not choice.

 

[ukcatfan]

Let me establish one thing. I completely understand all of the concepts. I do not need them explained. What I am wanting information on is the differences between a DSLR without image stabilization and a point and shoot with image stabilization. I have the P&S w/IS and have tried out a number of DSLRs, but have never had them side by side to compare. My DW does not want to take a step down in "being able to get the shot" by moving to a DSLR. Using a higher ISO, such as 1600, is completely acceptable to us. It is difficult for me to make this comparison to her easily, b/c it is like comparing apples to oranges and I am only holding an apple.

My thinking is that the DSLR can perform about as well without IS as the P&S does with IS. I am not saying that they would be on the exact same exposure settings, but they would end up with the same results. I am thinking this because the DSLR lens is more capable of gathering the light and the sensor is more sensitive.

I probably need someone that regularly uses both to answer this or I need to actually go in to a store to test both at the same time.

 

[Kelly Grannell]

My thinking is that the DSLR can perform about as well without IS as the P&S does with IS. I am not saying that they would be on the exact same exposure settings, but they would end up with the same results.

IF your subject is still, then yes, they will be the same

DSLR lens is more capable of gathering the light and the sensor is more sensitive.

the answers are maybe and no.

Better light gathering: yes, should you choose a better lens.
Sensor being more sensitive, not really, just a much larger surface area therefore the effect is being more sensitive.

hope it helps.

 

[handicap18]

I'm guessing that your going to have to do the side by side comparisions yourself. I don't know of anyone who has done it. At least no one has brought it up before.

FWIW is anything at all:
Also keep in mind that both Nikon and Canon have a number of lenses with Vibration Reduction and Image Stabalization. They are more expensive than the lenses without, but they are available. There are also very inexpensive lenses (relatively speaking) that have very fast apertures and therefor have a lot less need for any VR or IS. Nikon and Canon both make a 50mm f/1.8 (both $100 or less), Sigma has a 28mm f/1.8 for about $250, and Nikon (and I think Canon too) has an 85mm f/1.8 and there are others as well. With dSLR's one of the bigger advantages of the VR & IS is being able to hold the camera at the longer ends (200mm and up) without using a tripod. Camera shake can be a PITA.

Combining the fast aperture with a high ISO on a dSLR you'll probably have a better chance at getting the shot than a P&S with IS. The IS doesn't stop subject movement, only keeps the camera more steady.

Another option is to see if you can find people with examples of the indoor rides at Disney (Pirates, IASM, Great Movie Ride, etc...) with a P&S with IS but without using a flash. I have a bunch taken with a 50mm f/1.8 at 1600 that came out great. Though I think the 28mm f/1.8 would be better on a dSLR, 50mm is a bit to tight sometimes.