[HSV]

Originally Posted by kkr2k2

A 550D body is 34K, 50mm f1.8 is 5k. So you are paying 18K for 18-135 as part of kit. You can buy a 18-55 and 55-250 for that money unless of-course you NEED to have a walk around zoom lens!! BTW, did you check for 18-200 as well as kit lens??

I have read a couple of reviews of the 18-55+55-250 vs 18-135. And after a lot of introspection I figured that It'd be more value (to me) in case i bought one lens as opposed to two - although it would mean sacrificing a little on the zoom,but gaining on higher apperature at 135, alongwith slightly better construction et all.

I am a newbie with DSLRs and would need to negotiate the learning curve first.

I wasnt too keen on the 18-200 as that means a higher jump in cost alongwith the more distortion vis-a-vis the 18-135. So i decided on the middle path. what say you?

regards,

[typeOnegative]

Originally Posted by HSV

I have read a couple of reviews of the 18-55+55-250 vs 18-135. And after a lot of introspection ...
regards,

Your reasoning is sound. If you are learning, then any lens with a larger aperture play is good. A prime is best imho.

[pawan_pullarwar]

Originally Posted by HSV

I have read a couple of reviews of the 18-55+55-250 vs 18-135. And after a lot of introspection I figured that It'd be more value (to me) in case i bought one lens as opposed to two - although it would mean sacrificing a little on the zoom,but gaining on higher apperature at 135, alongwith slightly better construction et all.

I am a newbie with DSLRs and would need to negotiate the learning curve first.

I wasnt too keen on the 18-200 as that means a higher jump in cost alongwith the more distortion vis-a-vis the 18-135. So i decided on the middle path. what say you?

regards,

18-135 is good choice for newbie. If you are considering zoom lens, 55-250 has very little zoom and you will not be happy with its zoom coverage. For the zoom lens, you should buy atleast 500mm lens.

[bbkp]

Zoom gives us the reach to the subjects and there are numerous other factors to consider before taking a decision. The 18-135mm and the 18-200 are not the best lenses when it comes to chromatic Abberation. Neither are they the sharpest of the lot.

In my opinion, the 18-55mm and the 55-250 mm are much better lenses because they are more sharper and suffer lesser levels of Chromatic Abberations than the 18-135mm and 18-200mm.

If someone is picking an SLR, they should always be prepared to change lenses every now and then - infact that is one of the main purposes of an SLR Camera - Ability to have multiple lenses onto the same camera.

In all scenarios, the 18-55mm IS along with the 55-250mm IS have better image clarity and will deliver better results than the 18-135 and the 18-200mm lenses. The only issue that you may notice is that the 55-250mm lens suffer from heavy barrel distortion. As long as you are OK to step down the aperture by couple of stops and are willing to stay below f6, it should be alright and it is a non-issue.

My kit is a Canon 7D, Canon EF-S 15-85mm IS USM, Tamron 70-300mm VC USD Lens and will be soon adding Canon 430 EX II Flash gun to the kit. I absolutely love the Tamron lens. Usually, their lens are slightly below par to the Canon / Nikon. But this lens is their first USD lens and it beats some of the premium lenses of Canon and Nikon by a huge margin.

In terms of deciding the lens, a lot also depends on the sensor - How much clarity does the sensor need? If you are onto a 6 - 10 MP sensor, then even a not so sharp lens can do the job. Adding a high quality lens with more sharpness and resolution to it doesn't make sense, because, beyond a point, the sensor is not in a position to accept and record the extra sharpness offered.

However, if you are using a high resolution sensor (upwards of 12 MP) like a Canon 550D or a 7D, then, you cannot afford to have ordinary lenses, because the sensor is now in a position to accept and record images at higher sharpness levels. Images will look blurry and less sharper with an ordinary lens and it becomes necessary to use high quality and premium lenses that are capable to resolve upto the demands of the sensor.

So, while a lens is OK to go with a Canon 450, it might not be OK with a 550D / 7D. A premium lens however can work on both of them. That is why in terms of building up on an SLR kit, focussing more on lenses than the camera body pays off in the long run.

Regards
Prasad

[bbkp]

Originally Posted by bblost

Can someone suggest a good (500$-600$) range dslr for taking pics of jewelery.

Essentially Gemstones.

My friend designs jewelery and wants to get a good camera so she can showcase the same in a very professional but personal website.

Hi,

You need a camera with good macro capabilities and wide aperature. Shooting Jewellery involves working from very short distances and a wide aperature will help you isolate the jewellery from other items in the frame. Difficult to suggest a good SLR for 500-600 dollars. This is the beginner's range. I would rather advice you to look for a point and shoot with a very bright lens - f2.0.

If you want to go for an SLR itself, Pentax K-r with 18-55mm is a good bet. Same is the case with Canon 550D with 18-55mm or a Nikon D3100 with 18-55mm. Please make note that the Canon and Nikon will be expensive to the Pentax.

Regards
Prasad

[bbkp]

Originally Posted by amitk26

Guys quick question about Canon 15-85 IS USM and does anyone know latest price for this in grey and also with B&W.
Does canon non L lens purchased abroad carry international warranty or the warranty is country specific like bodies ?

Also pointers on price of Sigma 17-70 OS will be appreciated.

Hi Amit,

The Canon 15-85 mm IS USM is a EF-S lens and not a EF lens. So, be prepared to be using it only on APS-C sensors and not on full frame ones. It should comes for about 30 K in grey and about 40 K in B&W.

The Sigma is not a match to the canon and you will be better off with the Canon 18-55mm and 55-250mm IS combo - that way you will get a better range as well.

Cheers
Prasad

[kkr2k2]

Originally Posted by bbkp

.....
In terms of deciding the lens, a lot also depends on the sensor - How much clarity does the sensor need? If you are onto a 6 - 10 MP sensor, then even a not so sharp lens can do the job. Adding a high quality lens with more sharpness and resolution to it doesn't make sense, because, beyond a point, the sensor is not in a position to accept and record the extra sharpness offered. .....

This is the second time I have come across someone who is talking about deciding the lens based on the sensor!! The last was from a guy who is into the sensor development and he was talking about it after his purchase of $1000 Carl-Zeiss lenses by selling of his 'L' lenses!!!

[amitk26]

Originally Posted by bbkp

Hi Amit,

The Canon 15-85 mm IS USM is a EF-S lens and not a EF lens. So, be prepared to be using it only on APS-C sensors and not on full frame ones. It should comes for about 30 K in grey and about 40 K in B&W.

Yes I know that and have no plan for Full frame , I asked that question because a frined was returning to India who could have carried 15-85 IS USM at 635$ that day which was an excellent price considering that in India the price being quoted is anything between 44K to 50K but I missed informing him by few hours.

Originally Posted by bbkp

The Sigma is not a match to the canon and you will be better off with the Canon 18-55mm and 55-250mm IS combo - that way you will get a better range as well.

Cheers
Prasad

This is simply not correct, Subsequent to that post I did a lot of search. MTF charts ( as per photozone.de ) for Sigma between 3.5 to 5.6 exceeds Canon the only problem it is little soft at F4 at 70mm and F2.8 at 17mm but if you stop down to F5.6 or F3.5 then it is fine. So it is sharper in the range which is available with Canon and also if you badely need F2.8 at 17mm it is available atleast.
Real Advantage with Canon is 15mm at wide end but Sigma 17-70 OS is bang for buck lens with half the price. The only concern was about the warranty and QC anyway in India Canon 15-85 IS USM with B&W is 45K and even in grey people quote crazy prices maybe because lens is not in stock with them.
Whereas with international warranty it costs around 30K abroad so I am waiting for some one who can bring it back for me as there is no urgent need my current lenses fulfill the needs.

[amitk26]

Originally Posted by bbkp

In terms of deciding the lens, a lot also depends on the sensor - How much clarity does the sensor need? If you are onto a 6 - 10 MP sensor, then even a not so sharp lens can do the job. Adding a high quality lens with more sharpness and resolution to it doesn't make sense, because, beyond a point, the sensor is not in a position to accept and record the extra sharpness offered.

However, if you are using a high resolution sensor (upwards of 12 MP) like a Canon 550D or a 7D, then, you cannot afford to have ordinary lenses, because the sensor is now in a position to accept and record images at higher sharpness levels. Images will look blurry and less sharper with an

The el-chepo lens of today also gives more then 100 line pair per mm resolution which exceeds the sensor resolution from latest greatest sensors so this is actually a bankum marketing tactic by companies.
Anyway all the consumer bodies today are in excess of 10MP

Even if I have to accept that sensor resolution is very high then also fitting a cheap lens does not harm the image in any way. It depends on how much exactly you are going to blow up the image.

The maximum resolution possible by human ratina is 50 cycles per degree ( 1 cycle is 1 line pair) which roughtly translates to 447 pixels per inch at distance of 10 inch but this is retina resolution and not of eye.
The resolution of human eye is extimated to be 30 cycles per degree and that means 330 pixels per inch at a distance of 10 inch and this is what Steve Jobs touted as retina display.

This kind of high resolution makes sense only for LCD / AMOLED displays becuase when you print the inks have lot less tonal range and anyway your 330 Pixel image gets compressed in tonal range ( even if you print at 1800DPI)

You can have higher resolution with latest greatest lenses + sensors but the real question is can anyone see it untill you are blowing them up to wall sized prints for giant hoardings or projecting them in cinema hall ?

For details refer to the MTF charts of various lenses with various sensors at photozone.de.

[bbkp]

Originally Posted by amitk26

Yes I know that and have no plan for Full frame , I asked that question because a frined was returning to India who could have carried 15-85 IS USM at 635$ that day which was an excellent price considering that in India the price being quoted is anything between 44K to 50K but I missed informing him by few hours.



This is simply not correct, Subsequent to that post I did a lot of search. MTF charts ( as per photozone.de ) for Sigma between 3.5 to 5.6 exceeds Canon the only problem it is little soft at F4 at 70mm and F2.8 at 17mm but if you stop down to F5.6 or F3.5 then it is fine. So it is sharper in the range which is available with Canon and also if you badely need F2.8 at 17mm it is available atleast.
Real Advantage with Canon is 15mm at wide end but Sigma 17-70 OS is bang for buck lens with half the price. The only concern was about the warranty and QC anyway in India Canon 15-85 IS USM with B&W is 45K and even in grey people quote crazy prices maybe because lens is not in stock with them.
Whereas with international warranty it costs around 30K abroad so I am waiting for some one who can bring it back for me as there is no urgent need my current lenses fulfill the needs.

Well, the think with SLR cameras is that you buy the lenses forever (as you can hold on to them) and change the bodies as newer technologies with better sensors is available. So, my recommendation will always be to be on the lookout for lenses that are usable on full-format as well. That way, we have the lenses ready as and when there is an affordable ful-frame camera body in the market. Having said that, I bought the Canon 7D along with this very lens. Didn't realise it then and only realised my mistake after the purchase.

Coming to the wide-angle prespective, let me tell you that a lot of my results at 15mm suffer from heavy barrel distortion and Vignetting. You might want to think about it - while it gives you a wide angle, it comes at a cost. Infact, I was not happy with that aspect. Other than that there is no issues. It is a very sharp lens. I avoid shooting with this below 25mm.

In terms of Sigma lens being better than Canon, I suggest you to still rethink because of the quality issues which Sigma has. Pick 2 canon lenses and they will be pretty similar to each other. Same for Nikon or Pentax or Zeiss or any other primary brand. Tamron and Sigma are different. They don't seem to enjoy the same levels of quality assurance. Recently, I has tried a Sigma lens at a camera shop over here in Sydney and the results were just amazing. But then, my friend burnt his fingers with the same lens as his results are pathetic. With Sigma and Tamron, there is a very high chance that you may get your hands onto a bad one.

In that, it is slow to focus when compared to the Canon ones. The Canon has a super fast USM, where as the Sigma has a slow standard AF motor and takes atleast twice the time to focus when compared to the canon. Being a conventional AF motor means that it is going to be noisy. So, for a real quick shot, it will be caught napping. I can vouch for Canon 15-85mm as a user of that lens - it is super fast in terms of focussing speed.

Cheers
Prasad

[bbkp]

Originally Posted by amitk26

The el-chepo lens of today also gives more then 100 line pair per mm resolution which exceeds the sensor resolution from latest greatest sensors so this is actually a bankum marketing tactic by companies.
Anyway all the consumer bodies today are in excess of 10MP

Even if I have to accept that sensor resolution is very high then also fitting a cheap lens does not harm the image in any way. It depends on how much exactly you are going to blow up the image.

The maximum resolution possible by human ratina is 50 cycles per degree ( 1 cycle is 1 line pair) which roughtly translates to 447 pixels per inch at distance of 10 inch but this is retina resolution and not of eye.
The resolution of human eye is extimated to be 30 cycles per degree and that means 330 pixels per inch at a distance of 10 inch and this is what Steve Jobs touted as retina display.

This kind of high resolution makes sense only for LCD / AMOLED displays becuase when you print the inks have lot less tonal range and anyway your 330 Pixel image gets compressed in tonal range ( even if you print at 1800DPI)

You can have higher resolution with latest greatest lenses + sensors but the real question is can anyone see it untill you are blowing them up to wall sized prints for giant hoardings or projecting them in cinema hall ?

For details refer to the MTF charts of various lenses with various sensors at photozone.de.

It starts making a difference when you start to really use the high megapixels. It is when you zoom the pictures to more than 50% that you start noticing the differences. That is precisely one of the reasons why real professionals go for full-frame sensors with high MPs on the sensors and always couple the bodies like the 5D or the 1D with professional quality L series lenses.
In terms of photography, a lot of people indulge in cropping the photos, which by the way is very important. To have an ability to crop an image and still have an acceptable quality output is very essential.
Images will turn-up blotchy if the lens cannot supplement the performance of the sensor. The lens need to be as sharp enough to be able to cater to each pixel. If it can't, then, blotchy images. Lens being better and the sensor having less MP is still fine though.

Secondly comparing the MTF charts on Photozone is not the most brilliant thing to do - Those charts are studied using the JPEG output and not the RAW outputs of the camera. So, the post-processing capabilities and the settings on the camera like White Balancing etc. come into play. In terms of actual comparison when testing lenses, we should be looking at RAW files and not JPEGs.

Just as a case in the point, 7D has a stored setting for canon 15-85mm, so, the JPEGs are corrected for barrel distortion and vignetting (doesn't do a good job though), but, it doesn't have such settings stored for the Sigma lens. So, the actual comparison of how much a lens is able to resolve can only come by comparing RAW files and not JPEGs. Most of SLR work happens in RAW.

Cheers
Prasad

Cheers
Prasad

[bbkp]

Originally Posted by kkr2k2

This is the second time I have come across someone who is talking about deciding the lens based on the sensor!! The last was from a guy who is into the sensor development and he was talking about it after his purchase of $1000 Carl-Zeiss lenses by selling of his 'L' lenses!!!

Yes, very true. It is the sensor and demands of the sensor that rule on which lens to pair it with. Just as a case in the point, attaching a high quality professional L series lens before the sensor of a point and shoot doesn't do any justice to the lens. Needless to say, an enlarged model of the lens of a point and shoot camera cannot match to the requirements of the sensor in a high quality SLR camera. It is the combo of the sensor and the lens that works basically.

I have to though add that you will not go wrong with a high quality lens because it can resolve higher than what is needed by a less MP sensor, while catering to the requirements of a high MP sensor.

Regards
Prasad

[amitk26]

Originally Posted by bbkp

It starts making a difference when you start to really use the high megapixels. It is when you zoom the pictures to more than 50% that you start noticing the differences. That is precisely one of the reasons why real professionals go for full-frame sensors with high MPs on the sensors and always couple the bodies like the 5D or the 1D with professional quality L series lenses.

Check your facts once more 5D MK2 and 1D have less pixel density then 550D or 60D or 7D so if you crop then you will see more pixelation in full frame rather then in APS-C use of Full frame is for entirely different reason and that is to get larger field of view at wide angle and not for cropping.

If you use a L lens of Zeiss lens on Cropped body actually you are using a central portion of image so you will get better picture because resolution at corners is always less for any lens.

Secondly the lens aberration correction settings also do it in post processing and MTF figure for lens is different from lens + sensor combination you get at photozone but still you can compare the lenses as long as they have same sensor.

You need better lenses be it on 6MP or 21 MP because of colour rendering focus sharpness and less distortions , just that you have 15MP sensor does not automatically mean that pictures with ordinary lenses will look worse then say if same lens was attached to 6MP.

[bbkp]

Originally Posted by amitk26

Check your facts once more 5D MK2 and 1D have less pixel density then 550D or 60D or 7D so if you crop then you will see more pixelation in full frame rather then in APS-C use of Full frame is for entirely different reason and that is to get larger field of view at wide angle and not for cropping.

If you use a L lens of Zeiss lens on Cropped body actually you are using a central portion of image so you will get better picture because resolution at corners is always less for any lens.

Secondly the lens aberration correction settings also do it in post processing and MTF figure for lens is different from lens + sensor combination you get at photozone but still you can compare the lenses as long as they have same sensor.

You need better lenses be it on 6MP or 21 MP because of colour rendering focus sharpness and less distortions , just that you have 15MP sensor does not automatically mean that pictures with ordinary lenses will look worse then say if same lens was attached to 6MP.

I am sorry and I beg to differ. Pixelation has got nothing to do with Pixel density on the sensor. A photo with a 6 MP output will have the same pixelation irrespective of whether it comes from a APS-C sensor or a Full-frame sensor. a 6 MP result is pretty good to go for an A4 or an even bigger A3 print - this is irrespective of the sensor size and pixel density of the sensor. But, you try and print a 2 MP photo on an A3 size print, it is then that you will start to see the pixelation. More megapixels always means that you have more capability to crop images.
Why full frame sensors are better than APS-Cs - The reason is that they have more area per pixel than an APS-C cropped sensor. A 10 MP full-frame sensor has more than twice the area per pixel than a 10 MP APS-C sensor. As a result, the pixels in the full-frame sensor can capture more light per pixel because the area per pixel is larger. The end result is very less sensor noise at high sensitivity because each pixel has enough light capturing capability to record a signal as against noise. It is precisely for this reason that full-frame cameras always report lesser noise than cameras with APS-C sensors.

From a photography perspective as well, a full frame sensor is better because the size of the sensor starts to play a lot of effect in Depth of Field. Full Frame Sensors will provide a narrower depth of field for the same aperature settings when compared to an APS-C sensor and this results in better bokeh - with everything else kept the same. And yes, you are right when you say that you get a larger field of view at wide angle with the same lens. But the real effect of the full frame sensor from a photography perspective has got to do with the effect of lot narrower Depth of Field.

Secondly, if you put an L-series lens on a camera, then comparitively, the full-frame sensor will still report better results purely because of it's capability to capture more light. Going by your logic, the smaller the sensor, the better images you get as the sensor gets the sweet spot of the lens but that's not the way how it works. It is because of the more area on a full-frame sensor , that it can capture more light and it is because it can capture more light, they result in a much lesser noise and better outputs even in low-light situations.

As suggested, when we are comparing lenses, then, post-processing introduced by the camera needs to be thrown out of the window, because, it is the RAW file that has the exact information as received by the sensor. A lot of processing is done by the camera and comparing MTF charts for JPEGs doesn't make any sense. If a lens has a problem in projecting light properly in a certain part of the image, the post-processing done by the camera might actually correct the issue and not report the problem at all and the images might look similar to those taken by cameras without any such issues - So, would that make sense to say that the lens is on par or better than others? A number of such defects gets overwritten by the post-processing. So, it is not correct to compare MTF charts for resolution of lenses using JPEGs, even though it is on the same camera and the same sensor. Post-processing may fix some issues for one lens while not fixing some for the other. It is only when you compare the MTF of the RAW files that you can get to know the exact results of which lens is better.

[amitk26]

Originally Posted by bbkp

I am sorry and I beg to differ. Pixelation has got nothing to do with Pixel density on the sensor. A photo with a 6 MP output will have the same pixelation irrespective of whether it comes from a APS-C sensor or a Full-frame sensor. a 6 MP result is pretty good to go for an A4 or an even bigger A3 print -

Were you not talking about cropping ? If you need to crop a butterfly from a scene on an 18MP APS-C or 21 MP Full frame where you will get more pixels?

You are mixing up too many things just check the MTFs of a D7 versus MTF from 5D MK2 with same lens ( any lens ) and see why you get more lines pain per mm on APS-C rather then on FF with exact same lens.

About the JPEG vs RAW thing they convert to JPEG for obvious reasons and photo-zone state that tests across the different systems are not comparable becuase of different RAW convertors but in case of Canons same RAW convertor applies for both APS-C and FF. They do not mean that they shoot in camera JPG.

Read the FAQ for lens tests from Photozone.de

Photozone Lens Test FAQ

A similar discussion is going on on JJMF so you can refer to same.
Pixels - How many do we need anyway?

And also on this thread I posted details on how human eye resolves and max resolution with calculations converting angular resolution to PPI
The audacity of Olympus